New Trends in Crystals at Saudi Arabia

A special issue of Crystals (ISSN 2073-4352). This special issue belongs to the section "Organic Crystalline Materials".

Deadline for manuscript submissions: closed (31 December 2021) | Viewed by 141354

Special Issue Editors


E-Mail Website1 Website2
Guest Editor
Department of Chemistry, King Saud University, Riyadh 11451, Saudi Arabia
Interests: drug discovery; protein–protein interaction inhibitor; organic synthesis of biological active compounds; asymmetric synthesis; X-ray single crystallography
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Guest Editor
Institute of Chemistry, Saint Petersburg State University, 198504 St. Petersburg, Russia
Interests: quantum and computational chemistry; computer modeling; non-covalent interactions; reaction mechanisms; catalysis; coordination and organometallic chemistry; supramolecular chemistry
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

One of the most important approaches for 3D chemical structure elucidation of micro/macromolecules remains single crystal X-ray crystallography. This non-destructive analytical technique can provide accurate data related to the exact chemical feature of the internal crystal lattice of solid crystalline compounds, that also afford unit cell dimensions, bond angles and bond length, atoms ordering, etc. In this virtual conference, I will present some examples and outline how single-crystal XRD has helped us to confirm molecular structures for biologically active compounds.

We invite researchers to contribute to the Special Issue on New Trends in Crystals at Saudi Arabia, which is intended to serve as a unique multidisciplinary forum covering broad aspects of science, technology and the application of single crystal X-ray crystallography for the synthetic and natural small molecules relevant to biological activities.

The potential topics include, but are not limited to:

  • Synthesis and single crystal X-ray crystallography.
  • Supramolecular assembly of coordination polymers.
  • Chemical insight of the molecular structure.
  • Both experimental and theoretical/computational modelling.

Prof. Dr. Assem Barakat
Dr. Alexander S. Novikov
Guest Editors

Manuscript Submission Information

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Keywords

  • Crystal and molecular structure
  • Coordination complexes
  • Heterocyclic molecules
  • New ligands
  • Computational study
  • Bioactive compounds
  • Natural products
  • Nano-materials
  • MOFs
  • Crystallography

Published Papers (57 papers)

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Research

20 pages, 3066 KiB  
Article
Chemical Characterization of Taif Rose (Rosa damascena Mill var. trigentipetala) Waste Methanolic Extract and Its Hepatoprotective and Antioxidant Effects against Cadmium Chloride (CdCl2)-Induced Hepatotoxicity and Potential Anticancer Activities against Liver Cancer Cells (HepG2)
by Reham Z. Hamza, Hatim M. Al-Yasi, Esmat F. Ali, Mustafa A. Fawzy, Tharwat G. Abdelkader and Tarek M. Galal
Crystals 2022, 12(4), 460; https://doi.org/10.3390/cryst12040460 - 25 Mar 2022
Cited by 10 | Viewed by 2942
Abstract
Taif rose (Rosa damascena Mill) is one of the most important economic products of the Taif Governorate, Saudi Arabia. Cadmium chloride (CdCl2) is a common environmental pollutant that is widely used in industries and essentially induces many toxicities, including hepatotoxicity. [...] Read more.
Taif rose (Rosa damascena Mill) is one of the most important economic products of the Taif Governorate, Saudi Arabia. Cadmium chloride (CdCl2) is a common environmental pollutant that is widely used in industries and essentially induces many toxicities, including hepatotoxicity. In this study, the major compounds in the waste of Taif rose extract (WTR) were identified and chemically and biologically evaluated. GC–MS analysis of WTR indicated the presence of many saturated fatty acids, vitamin E, triterpene, dicarboxylic acid, terpene, linoleic acid, diterpenoid, monoterpenoid, flavonoids, phenylpyrazoles, and calcifediol (vitamin D derivative). The assessment of potential anticancer activity against HepG2 cells proved that WTR had a high cell killing effect with IC50 of 100–150 µg/mL. In addition, WTR successfully induced high cell cycle arrest at G0/G1, S, and G2 phases, significant apoptosis, necrosis, and increased autophagic cell death response in the HepG2 line. For the evaluation of its anti-CdCl2 toxicity, 32 male rats were allocated to four groups: control, CdCl2, WTR, and CdCl2 plus WTR. Hepatic functions and antioxidant biomarkers (SOD, CAT, GRx, GPx, and MDA) were examined. Histological changes and TEM variations in the liver were also investigated to indicate liver status. The results proved that WTR alleviated CdCl2 hepatotoxicity by improving all hepatic vitality markers. In conclusion, WTR could be used as a preventive and therapeutic natural agent for the inhibition of hepatic diseases and the improvement of redox status. Additional in vitro and in vivo studies are warranted. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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11 pages, 2547 KiB  
Article
Synthesis, X-ray Structure, Antimicrobial and Anticancer Activity of a Novel [Ag(ethyl-3-quinolate)2(citrate)] Complex
by Mezna Saleh Altowyan, Mostafa A. El-Naggar, Morsy A. M. Abu-Youssef, Saied M. Soliman, Matti Haukka, Assem Barakat and Ahmed M. A. Badr
Crystals 2022, 12(3), 356; https://doi.org/10.3390/cryst12030356 - 07 Mar 2022
Cited by 5 | Viewed by 2248
Abstract
A novel Ag(I) citrate complex with ethyl-3-quinolate (Et3qu) was synthesized. Its structure was confirmed using X-ray single crystal to be [Ag(Et3qu)2(citrate)]. It crystallized in the Triclinic crystal system and P-1 space group with unit cell parameters of a [...] Read more.
A novel Ag(I) citrate complex with ethyl-3-quinolate (Et3qu) was synthesized. Its structure was confirmed using X-ray single crystal to be [Ag(Et3qu)2(citrate)]. It crystallized in the Triclinic crystal system and P-1 space group with unit cell parameters of a = 8.6475(2) Å, b = 11.4426(3) Å, c = 15.2256(3) Å, α = 73.636(2)°, β = 79.692(2)° and γ = 86.832(2)°, while the unit cell volume was 1422.19(6) Å3. In the unit cell, there are two [Ag(Et3qu)2(citrate)] molecules and one unit as the asymmetric formula. The molecular structure comprised one Ag(I) coordinated with two Et3qu molecules via two almost equidistant Ag-N bonds and one citrate ion acting as a mono-negative monodentate ligand via a short Ag-O bond (2.5401(14) Å). Hence, Ag(I) is tri-coordinated and has a highly distorted triangular planar coordination geometry which is more like to be described as a slightly distorted T-shape. The supramolecular structure of the [Ag(Et3qu)2(citrate)] complex was analyzed using Hirshfeld calculations. The H···H (39.3–40.1%), O···H (33.2-34.0%), C···C (9.1–9.5%) and C···H (7.2–7.4%) contacts shared significantly in the packing of the studied Ag(I) complex. The antimicrobial and anticancer activities of the Ag(I) complex were investigated. The [Ag(Et3qu)2(citrate)] complex has broad-spectrum antimicrobial activity specifically against the fungus A. fumigatus. In addition, the IC50 values of 1.87 ± 0.09 µg/mL and 0.95 ± 0.06 µg/mL against the breast MCF-7 and lung A-549 cell lines, respectively, revealed the potent anticancer activity of the [Ag(Et3qu)2(citrate)] complex compared to the free Et3qu (IC50 = 30.64 ± 1.98 and 22.89 ± 1.48 µg/mL, respectively). Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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17 pages, 1538 KiB  
Article
In Silico Investigation of Some Compounds from the N-Butanol Extract of Centaurea tougourensis Boiss. & Reut.
by Saliha Dassamiour, Mohamed Sabri Bensaad, Leila Hambaba, Mohamed Akram Melakhessou, Rokayya Sami, Amina A. M. Al-Mushhin, Amani H. Aljahani and Luluah M. Al Masoudi
Crystals 2022, 12(3), 355; https://doi.org/10.3390/cryst12030355 - 07 Mar 2022
Cited by 1 | Viewed by 2135
Abstract
Bioinformatics as a newly emerging discipline is considered nowadays a reference to characterize the physicochemical and pharmacological properties of the actual biocompounds contained in plants, which has helped the pharmaceutical industry a lot in the drug development process. In this study, a bioinformatics [...] Read more.
Bioinformatics as a newly emerging discipline is considered nowadays a reference to characterize the physicochemical and pharmacological properties of the actual biocompounds contained in plants, which has helped the pharmaceutical industry a lot in the drug development process. In this study, a bioinformatics approach known as in silico was performed to predict, for the first time, the physicochemical properties, ADMET profile, pharmacological capacities, cytotoxicity, and nervous system macromolecular targets, as well as the gene expression profiles, of four compounds recently identified from Centaurea tougourensis via the gas chromatography–mass spectrometry (GC–MS) approach. Thus, four compounds were tested from the n-butanol (n-BuOH) extract of this plant, named, respectively, Acridin-9-amine, 1,2,3,4-tetrahydro-5,7-dimethyl- (compound 1), 3-[2,3-Dihydro-2,2-dimethylbenzofuran-7-yl]-5-methoxy-1,3,4-oxadiazol-2(3H)-one (compound 2), 9,9-Dimethoxybicyclo[3.3.1]nona-2,4-dione (compound 3), and 3-[3-Bromophenyl]-7-chloro-3,4-dihydro-10-hydroxy-1,9(2H,10H)-acridinedione (compound 4). The insilico investigation revealed that the four tested compounds could be a good candidate to regulate the expression of key genes and may also exert significant cytotoxic effects against several tumor celllines. In addition, these compounds could also be effective in the treatment of some diseases related to diabetes, skin pathologies, cardiovascular, and central nervous system disorders. The bioactive compounds of plant remain the best alternative in the context of the drug discovery and development process. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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12 pages, 4030 KiB  
Article
Synthesis, X-ray Single-Crystal Analysis, and Anticancer Activity Evaluation of New Alkylsulfanyl-Pyridazino[4,5-b]indole Compounds as Multitarget Inhibitors of EGFR and Its Downstream PI3K-AKT Pathway
by Eid E. Salama, Ibrahim O. Althobaiti, Matti Haukka and Ahmed T. A. Boraei
Crystals 2022, 12(3), 353; https://doi.org/10.3390/cryst12030353 - 04 Mar 2022
Cited by 3 | Viewed by 2301
Abstract
The alkylation of 3,5-dihydro-4H-pyridazino[4,5-b]indole-4-thione with benzyl bromide, ethyl chloroacetate, and allyl bromide in the presence of potassium carbonate (K2CO3) yielded new alkylsulfanylpyridazino[4,5-b]indole derivatives (i.e., compounds 46). Hydrazinolysis of ester 6 resulted in hydrazide 7. The [...] Read more.
The alkylation of 3,5-dihydro-4H-pyridazino[4,5-b]indole-4-thione with benzyl bromide, ethyl chloroacetate, and allyl bromide in the presence of potassium carbonate (K2CO3) yielded new alkylsulfanylpyridazino[4,5-b]indole derivatives (i.e., compounds 46). Hydrazinolysis of ester 6 resulted in hydrazide 7. The structure of compound 6 was verified by X-ray single-crystal analysis. Among the synthesized compounds, compound 6 exhibited the most promising cytotoxicity toward MCF-7 cells with an IC50 value of 12 µM. It showed potential inhibition activity toward EGFR, PI3K, and AKT in MCF-7 cells, with 0.26-, 0.49-, and 0.31-fold reductions in concentration compared to an untreated control. Additionally, it showed apoptosis-inducing activity in MCF-7 cells (47.98-fold); overall apoptosis increased to 38.87% compared to 0.81% in the untreated control, which disrupted the cell cycle at pre-G1 and S phases. Moreover, compound 6 exhibited good binding affinities toward the tested proteins (EGFR, PI3K, and AKT) and had binding energies ranging from −15.87 to −24.87 Kcal/mol. It also formed good interactions with essential amino acids inside the binding sites. Hence, compound 6 is recommended as an anti-breast cancer chemotherapeutic due to its effects on the EGFR-PI3K-AKT pathway. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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15 pages, 2506 KiB  
Article
Spectroscopic Characterization, Thermogravimetry and Biological Studies of Ru(III), Pt(IV), Au(III) Complexes with Sulfamethoxazole Drug Ligand
by Eid H. Alosaimi
Crystals 2022, 12(3), 340; https://doi.org/10.3390/cryst12030340 - 02 Mar 2022
Cited by 2 | Viewed by 1908
Abstract
Complexes of Ru(III), Pt(IV), and Au(III) with sulfamethoxazole (SMX) were experimentally produced. The resulted formations of novel metal complexes were discussed using several techniques, such as effective magnetic moment molar conductivity, IR, UV, and 1H NMR spectra, elemental analyses, thermal analysis, microscopic and [...] Read more.
Complexes of Ru(III), Pt(IV), and Au(III) with sulfamethoxazole (SMX) were experimentally produced. The resulted formations of novel metal complexes were discussed using several techniques, such as effective magnetic moment molar conductivity, IR, UV, and 1H NMR spectra, elemental analyses, thermal analysis, microscopic and XRD analyses. The X-ray diffraction patterns of the solid powders of the synthesized sulfamethoxazole complexes indicated their identical formulation. The surface uniformity of the complexes’ samples was confirmed by SEM images. These complexes appear as spots, dark in appearance, with particle sizes of 100–200 nanometers in transmission electron microscopy (TEM) pictures. The sulfamethoxazole ligand was shown to be bidentate coordinated to the metallic ions with sulfonyle oxygen and amido nitrogen groups, according to IR spectral data. Both Ru(III) and Au(III) complexes have an electrolytic nature, but the Pt(IV) complex has non-electrolytic properties. TG and DTG experiments proved the assigned composition and provided information regarding the thermal stability of complexes in a dynamic air atmosphere, according to the thermal analysis. The effect of the novel prepared complexes was examined for antibacterial and antifungal activity in vitro against a variety of pathogens, and they exceeded the sulfamethoxazole ligand in antibacterial activity. It was observed that the Pt(IV) complex has the ultimate activity versus all the assessed organisms relative to all compounds. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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22 pages, 4873 KiB  
Article
Cyclohexylammonium Hexaisothiocyanatonickelate(II) Dihydrate as a Single-Source Precursor for High Surface Area Nickel Oxide and Sulfide Nanocrystals
by Mohamed F. Aly Aboud, Abdulmalik M. BinTaleb, Hamdi Ben Yahia, Abdelhamid Albaid, Sultan Albishi, Rasheed Arasheed, Ibrahim Albinali, Fahad Albaqi, Khalid Anojaidi, Fahad Alqahtani, Asma M. Alenad, Kamal Taha and Abdulaziz Bagabas
Crystals 2022, 12(3), 315; https://doi.org/10.3390/cryst12030315 - 23 Feb 2022
Viewed by 2036
Abstract
Cyclohexylammonium hexaisothiocyanatonickelate(II) dihydrate, (C6H11NH3)4[Ni(NCS)6]·2H2O, was synthesized, for the first time, by a four-step method in a yield of 95%. The compound was fully characterized by elemental microanalysis, Fourier transform infrared (FTIR), [...] Read more.
Cyclohexylammonium hexaisothiocyanatonickelate(II) dihydrate, (C6H11NH3)4[Ni(NCS)6]·2H2O, was synthesized, for the first time, by a four-step method in a yield of 95%. The compound was fully characterized by elemental microanalysis, Fourier transform infrared (FTIR), ultraviolet-visible-near infrared (UV-Vis-NIR), and nuclear magnetic resonance (NMR) spectroscopy and thermogravimetry. A single crystal X-ray diffraction (SXRD) gave the monoclinic space group P21/c with a = 15.8179 (5) Å, b = 10.6222 (3) Å, c = 13.8751 (4) Å, β = 109.362 (1)°, V = 2199.45 (11) Å3, Z = 2 (T = 293 K) for this novel hybrid organic–inorganic compound. The title compound was employed as a single-source precursor for the synthesis of mesoporous, high surface area nickel oxide (53 Å; 452 m2/g) and nickel sulfide (46 Å; 220 m2/g) via pyrolysis under air at 550 °C or helium atmosphere at 500 °C, respectively. X-ray powder diffraction (XRPD) demonstrated the nanocrystalline nature of both NiO and NiS with an average crystallite size of 16 and 54 nm, respectively. Scanning electron microscope (SEM) indicated the formation of agglomerated, quasi-spherical particles of nickel oxide and agglomerated flake-like structures of nickel sulfide. The high surface area, porosity, and nanocrystallinity of both NiO and NiS, obtained via this approach, are promising for a wide spectrum of applications. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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19 pages, 10961 KiB  
Article
Synthesis and Spectroscopic Characterization of Dapagliflozin/Zn (II), Cr (III) and Se (IV) Novel Complexes That Ameliorate Hepatic Damage, Hyperglycemia and Oxidative Injury Induced by Streptozotocin-Induced Diabetic Male Rats and Their Antibacterial Activity
by Samy M. El-Megharbel, Eman H. Al-Thubaiti, Safa H. Qahl, Rasha A. Al-Eisa and Reham Z. Hamza
Crystals 2022, 12(3), 304; https://doi.org/10.3390/cryst12030304 - 22 Feb 2022
Cited by 9 | Viewed by 2768
Abstract
Diabetes mellitus (DM) causes an imbalance in the oxidative status of the human body. Three novel Dapagliflozin (Dapg) Zn (II), Cr (III) and Se (IV) complexes were prepared and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility, scanning electron microscopy (SEM) and [...] Read more.
Diabetes mellitus (DM) causes an imbalance in the oxidative status of the human body. Three novel Dapagliflozin (Dapg) Zn (II), Cr (III) and Se (IV) complexes were prepared and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility, scanning electron microscopy (SEM) and X-ray diffraction. The molar conductance values confirmed the non-electrolytic nature of the Dapg complexes. According to spectral data, Dapg acts as a bidentate ligand. The thermal analyses of the complexes were studied using the DSC technique. The surface morphology and particle sizes of the Dapg complexes were investigated using SEM and XRD. XRD confirmed the crystalline structure for the complexity. This study investigated the effect of novel metal complexes of Dapg with the metals Zn (II), Cr (III) and Se (IV) on oxidative injury and tissue damage in the hepatic tissue of streptozotocin (STZ)-induced diabetic male rats. DM was experimentally induced in male rats. The diabetic rats received Dapg, Dapg/Zn, Dapg/Cr and Dapg/Se orally for 30 successive days. Male rats exposed to STZ showed multi-histopathological alterations in their hepatic tissue, including inflammatory and structural changes. STZ elevated oxidative stress markers in the hepatic tissue and lowered the antioxidant defense enzymes. Supplementation of Dapg with Zn, Cr or Se novel complexes significantly prevented hepatic injury and suppressed the generation of reactive oxygen species. The Dapg/Zn complex was highly effective against Bacillus subtilis and Streptococcus penumonia, while Dapg/Cr was highly effective against Escherichia coli and Pseudomonas aeruginosa, and Dapg/Se was highly effective against Staphylococcus aureas. In conclusion, Dapg novel metal complexes with Zn, Cr or Se protect against oxidative injury and the pathophysiological and bacterial complications of DM and hepatic tissue injury. The Dapg novel metal complexes improved hepatic functions, reduced blood glucose levels and enhanced the levels of antioxidant defense enzymes in diabetic male rats. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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13 pages, 3449 KiB  
Article
Straightforward One-Pot Synthesis of New 4-Phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one Derivatives: X-ray Single Crystal Structure and Hirshfeld Analyses
by Ahmed T. A. Boraei, Matti Haukka, Manar Sopaih, Abdullah Mohammed Al-Majid, Saied M. Soliman, Assem Barakat and Ahmed A. M. Sarhan
Crystals 2022, 12(2), 262; https://doi.org/10.3390/cryst12020262 - 15 Feb 2022
Cited by 1 | Viewed by 2411
Abstract
A straightforward one-pot route for the synthesis of a new 4-phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one is reported form the direct hydrazinolysis of triketo ester and hydrazine hydrate in ethanol. 4-Phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one was subjected to aza-Michael addition and N-alkylation on reaction with a [...] Read more.
A straightforward one-pot route for the synthesis of a new 4-phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one is reported form the direct hydrazinolysis of triketo ester and hydrazine hydrate in ethanol. 4-Phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one was subjected to aza-Michael addition and N-alkylation on reaction with a set of alkylating agents in the presence of K2CO3. Hydrazinolysis of 4-phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one ester to hydrazide and conversion of hydrazide to thiosemicarbazide were successful. X-Ray single crystals analysis and 1H, 13C NMR were used for unambiguous structure confirmation. The O…H, N…H, C…N and C…C in 2, and the N…H, C…N, C…C, C…O and H…H interactions in 6 are the most important in the molecular packing based on Hirshfled analysis. Moreover, the presence of short C…C and C…N contacts in both compounds revealed the presence of π–π stacking interactions. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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13 pages, 3555 KiB  
Article
Efficient Consecutive Synthesis of Ethyl-2-(4-Aminophenoxy) Acetate, a Precursor for Dual GK and PPARγ Activators, X-ray Structure, Hirshfeld Analysis, and DFT Studies
by Mezna Saleh Altowyan, Saied M. Soliman, Magda M. F. Ismail, Matti Haukka, Assem Barakat and Mohammed Salah Ayoup
Crystals 2022, 12(2), 227; https://doi.org/10.3390/cryst12020227 - 05 Feb 2022
Viewed by 1851
Abstract
Herein, we report a facile synthesis of ethyl-2-(4-aminophenoxy)acetate 4 as a building synthon for novel dual hypoglycemic agents. This building template was synthesized by alkylation of 4-nitrophenol with ethyl bromo-acetate followed by selective reduction of the nitro group. This reduction methoddoes not require [...] Read more.
Herein, we report a facile synthesis of ethyl-2-(4-aminophenoxy)acetate 4 as a building synthon for novel dual hypoglycemic agents. This building template was synthesized by alkylation of 4-nitrophenol with ethyl bromo-acetate followed by selective reduction of the nitro group. This reduction methoddoes not require nascent hydrogen or any reaction complexity; it goes easily via consecutive reaction in NH4Cl/Fe to yield our target synthon as very pure crystals. This product was characterized by 1HNMR, 13CNMR, COSY, NOESY NMR spectroscopy, and elemental analysis. Additionally, its structure was studied and approved by X-ray single crystal structure determination. The unit cell parameters are a = 8.2104(6)Å, b = 10.3625(9)Å, c = 11.9562(9)Å, α = 101.787(7), β = 91.849(6), and γ = 102.755(7)°, indicating that 4 was crystallized in the triclinic crystal system. The cooperative non-covalent interactions are also discussed with the aid of Hirshfeld surface analysis. The H…H, H…C, and O…H interactions have a major contribution in the molecular packing of 4. Moreover, different quantum chemical parameters were computed and discussed based on DFT calculations. The experimental UV/Vis spectra showed two bands at 299 and 234 nm, which were calculated using the TD-DFT method at 286 (f = 0.068) and 226 nm (f = 0.294), respectively. These bands were assigned to HOMO→LUMO (95%) and HOMO→LUMO+2 (86%) transitions, respectively. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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17 pages, 8015 KiB  
Article
Explore Optical Solitary Wave Solutions of the kp Equation by Recent Approaches
by Hammad Alotaibi
Crystals 2022, 12(2), 159; https://doi.org/10.3390/cryst12020159 - 22 Jan 2022
Cited by 9 | Viewed by 2085
Abstract
The study of nonlinear evolution equations is a subject of active interest in different fields including physics, chemistry, and engineering. The exact solutions to nonlinear evolution equations provide insightful details and physical descriptions into many problems of interest that govern the real world. [...] Read more.
The study of nonlinear evolution equations is a subject of active interest in different fields including physics, chemistry, and engineering. The exact solutions to nonlinear evolution equations provide insightful details and physical descriptions into many problems of interest that govern the real world. The Kadomtsev–Petviashvili (kp) equation, which has been widely used as a model to describe the nonlinear wave and the dynamics of soliton in the field of plasma physics and fluid dynamics, is discussed in this article in order to obtain solitary solutions and explore their physical properties. We obtain several new optical traveling wave solutions in the form of trigonometric, hyperbolic, and rational functions using two separate direct methods: the (w/g)-expansion approach and the Addendum to Kudryashov method (akm). The nonlinear partial differential equation (nlpde) is reduced into an ordinary differential equation (ode) via a wave transformation. The derived optical solutions are graphically illustrated using Maple 15 software for specific parameter values. The traveling wave solutions discovered in this work can be viewed as an example of solutions that can empower us with great flexibility in the systematic analysis and explanation of complex phenomena that arise in a variety of problems, including protein chemistry, fluid mechanics, plasma physics, optical fibers, and shallow water wave propagation. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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18 pages, 3599 KiB  
Article
Modeling of Chloride Binding Capacity in Cementitious Matrices Including Supplementary Cementitious Materials
by Ahmed M. Abd El Fattah and Ibrahim N. A. Al-Duais
Crystals 2022, 12(2), 153; https://doi.org/10.3390/cryst12020153 - 21 Jan 2022
Cited by 6 | Viewed by 2306
Abstract
The improvement in the chloride binding capacity of concrete has been shown to increase corrosion resistance. The addition of supplementary cementitious materials (SCMs) to Portland cement has been proven to increase the binding capacity, except for silica fume, whereas the impact of chemical [...] Read more.
The improvement in the chloride binding capacity of concrete has been shown to increase corrosion resistance. The addition of supplementary cementitious materials (SCMs) to Portland cement has been proven to increase the binding capacity, except for silica fume, whereas the impact of chemical additives is not extensively addressed in the literature. This work studies the influence of SCMs and chemical additives, i.e., calcium nitrite inhibitor (CNI), migrating corrosion inhibitor (MCI), and Caltite as a hydrophobic material, on binding capacity. The addition of both corrosion inhibitors (MCI and CNI) has minimal effect on the binding capacity, while the addition of Caltite reduces the binding capacity by limiting the contact of the samples with the salt in water due to its hydrophobic nature. In addition, the study compares the performance of the available fitting–binding models against the available experimental work in the literature, and shows that the Freundlich isotherm is the best fitting model for describing the relationship between the binding capacity and the free chloride. The study further relates the binding capacity to different compositions in cement and SCMs, and shows, by conducting quantitative analysis, that the Al2O3 content is the dominant factor affecting the binding capacity. Finally, this work proposes a new model, which uses Al2O3 content and free salt concentration to predict the bound chloride. The model shows adequate correlations to the experimental work and, further, can be used in service-life modeling of concrete. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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11 pages, 1398 KiB  
Article
Active Bionanocomposite Coating Quality Assessments of Some Cucumber Properties with Some Diverse Applications during Storage Condition by Chitosan, Nano Titanium Oxide Crystals, and Sodium Tripolyphosphate
by Mahmoud Helal, Rokayya Sami, Eman Algarni, Garsa Alshehry, Huda Aljumayi, Amina A. M. Al-Mushhin, Nada Benajiba, Murthy Chavali, Nishant Kumar, Abdullah Iqbal, Salman Aloufi, Amal Alyamani, Nawal Madkhali and Abeer Almasoudi
Crystals 2022, 12(2), 131; https://doi.org/10.3390/cryst12020131 - 18 Jan 2022
Cited by 4 | Viewed by 2028
Abstract
Cucumbers have a short shelf-life of about 14 days, they are perishable due to the high moisture content. This study aimed to study the effects of nano-coating material such as titanium nanoparticles and chitosan with the addition of sodium tripolyphosphate as a crosslinker [...] Read more.
Cucumbers have a short shelf-life of about 14 days, they are perishable due to the high moisture content. This study aimed to study the effects of nano-coating material such as titanium nanoparticles and chitosan with the addition of sodium tripolyphosphate as a crosslinker to enhance cucumber quality during storage. Some essential physical, chemical, and biological parameters were determined. CH-Nano-ST (chitosan/nano titanium oxide crystals/sodium tripolyphosphate) retained the maximum greenness, −7.99, compared to CH-Nano samples, which recorded −7.31. CH-Nano (chitosan/nano titanium oxide crystals) remained the lightest, 44.38, and CH-Nano-ST was a little darker (43.73) compared to the others treatments. The discoloration was extra severe with control (22.30), which started to spoil after the end of the first week. After 21 days of the storage period at 10 °C, the reducing sugars content reduced to reach −0.64 g/100 g and −0.21 g/100 g for CH-Nano and CH-Nano-ST treatments, respectively. The CH-Nano-ST treatment presented a lower value of toughness, followed by CH-Nano at the end of the storage period. Moreover, the highest crispness index was detected for CH-Nano (5.12%), while CH-Nano-ST treatment had a slight decline to reach 4.92%. The biological results indicated that CH-Nano-ST treatment can be applied to delay the microbial contamination of Salmonella spp. in cucumbers as it reached 0.94 log CFU/g, while the CH-Nano treatment reached 1.09 log CFU/g, at the end of the storage period. In summary, nano-coating treatments with the addition of sodium tripolyphosphate can be applied to regulator postharvest quality measurements of the biological activities in cucumbers during storage at 10 °C until 21 days. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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16 pages, 5724 KiB  
Article
Depicting the DNA Binding and Cytotoxicity Studies against Human Colorectal Cancer of Aquabis (1-Formyl-2-Naphtholato-k2O,O′) Copper(II): A Biophysical and Molecular Docking Perspective
by Ebtisam Alolayqi, Mohd Afzal, Abdullah Alarifi, Abeer Beagan and Mohd Muddassir
Crystals 2022, 12(1), 15; https://doi.org/10.3390/cryst12010015 - 22 Dec 2021
Cited by 4 | Viewed by 2736
Abstract
In this study, we attempted to examine the biological activity of the copper(II)–based small molecule aquabis (1-formyl-2-naphtholato-k2O,O′)copper(II) (1) against colon cancer. The characterization of complex 1 was established by analytical and spectral methods in accordance with the single-crystal X-ray results. [...] Read more.
In this study, we attempted to examine the biological activity of the copper(II)–based small molecule aquabis (1-formyl-2-naphtholato-k2O,O′)copper(II) (1) against colon cancer. The characterization of complex 1 was established by analytical and spectral methods in accordance with the single-crystal X-ray results. A monomeric unit of complex 1 exists in an O4 (H2O) coordination environment with slightly distorted square pyramidal geometry (τ = ~0.1). The interaction of complex 1 with calf thymus DNA (ctDNA) was determined by employing various biophysical techniques, which revealed that complex 1 binds to ctDNA at the minor groove with a binding constant of 2.38 × 105 M–1. The cytotoxicity of complex 1 towards human colorectal cell line (HCT116) was evaluated by the MTT assay, which showed an IC50 value of 11.6 μM after treatment with complex 1 for 24 h. Furthermore, the apoptotic effect induced by complex 1 was validated by DNA fragmentation pattern, which clarified that apoptosis might be regulated through the mitochondrial-mediated production of reactive oxygen species (ROS) causing DNA damage pathway. Additionally, molecular docking was also carried out to confirm the recognition of complex 1 at the minor groove. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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12 pages, 3956 KiB  
Article
Synthesis of Unexpected Dimethyl 2-(4-Chlorophenyl)-2,3-dihydropyrrolo[2,1-a]isoquinoline-1,3-dicarboxylate via Hydrolysis/Cycloaddition/Elimination Cascades: Single Crystal X-ray and Chemical Structure Insights
by Mezna Saleh Altowyan, Saied M. Soliman, Matti Haukka, Nora H. Al-Shaalan, Aminah A. Alkharboush and Assem Barakat
Crystals 2022, 12(1), 6; https://doi.org/10.3390/cryst12010006 - 21 Dec 2021
Cited by 1 | Viewed by 2857
Abstract
Hydrolysis/[3 + 2] cycloaddition/elimination cascades employed for the synthesis of unexpected tricyclic compound derived from isoquinoline. Reaction of ethylene derivative 1 with the isoquinoline ester iminium ion 2 in alkaline medium (MeOH/NEt3) under reflux for 1 h resulted in the formation [...] Read more.
Hydrolysis/[3 + 2] cycloaddition/elimination cascades employed for the synthesis of unexpected tricyclic compound derived from isoquinoline. Reaction of ethylene derivative 1 with the isoquinoline ester iminium ion 2 in alkaline medium (MeOH/NEt3) under reflux for 1 h resulted in the formation of the fused pyrrolo[2,1-a]isoquinoline derivative 3. Its structure was elucidated by X-ray single crystal and other spectrophotometric tools. Hirshfeld calculations for 3 and its crystal structure analysis revealed the importance of the short O…H (19.1%) contacts and the relatively long H…C (17.1%), Cl…H (10.6%) and C…C (6.1%) interactions in the molecular packing. DFT calculations were used to compute the electronic and spectroscopic properties of the studied system. The studied compound has polar nature (3.5953 Debye). TD-DFT calculations assigned the shortest wavelength band (220 nm) to the HOMO−1→LUMO+2 (57%), HOMO−1→LUMO+4 (14%) mixed excitations. The calculated NMR chemical shifts correlated very well with the experimental data (R2 = 0.93–0.94). Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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13 pages, 11787 KiB  
Article
[3+2] Cycloaddition Reaction for the Stereoselective Synthesis of a New Spirooxindole Compound Grafted Imidazo[2,1-b]thiazole Scaffold: Crystal Structure and Computational Study
by Mezna Saleh Altowyan, Saied M. Soliman, Matti Haukka, Nora Hamad Al-Shaalan, Aminah A. Alkharboush and Assem Barakat
Crystals 2022, 12(1), 5; https://doi.org/10.3390/cryst12010005 - 21 Dec 2021
Cited by 3 | Viewed by 3159
Abstract
A new spirooxindole hybrid engrafted imidazo[2,1-b]thiazole core structure was designed and achieved via [3+2] cycloaddition reaction approach. One multi-component reaction between the ethylene derivative based imidazo[2,1-b]thiazole scaffold with 6-Cl-isatin and the secondary amine under heat conditions afforded the desired [...] Read more.
A new spirooxindole hybrid engrafted imidazo[2,1-b]thiazole core structure was designed and achieved via [3+2] cycloaddition reaction approach. One multi-component reaction between the ethylene derivative based imidazo[2,1-b]thiazole scaffold with 6-Cl-isatin and the secondary amine under heat conditions afforded the desired compound in a stereoselective manner. The relative absolute configuration was assigned based on single-crystal X-ray diffraction analysis. Hirshfeld calculations for 4 revealed the importance of the H…H (36.8%), H…C (22.9%), Cl…H (10.4%) and S…H (6.6%), as well as the O…H (4.7%), N…H (5.3%), Cl…C (1.6%), Cl…O (1.0%) and N…O (0.5%) contacts in the crystal stability. DFT calculations showed excellent straight-line correlations (R2 = 0.9776–0.9962) between the calculated and experimental geometric parameters. The compound has polar nature (3.1664 Debye). TD-DFT and GIAO calculations were used to assign and correlate the experimental UV-Vis and NMR spectra, respectively. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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19 pages, 6276 KiB  
Article
Synthesis, and Molecular Structure Investigations of a New s-Triazine Derivatives Incorporating Pyrazole/Piperidine/Aniline Moieties
by Ihab Shawish, Saied M. Soliman, Matti Haukka, Ali Aldalbahi, Assem Barakat and Ayman El-Faham
Crystals 2021, 11(12), 1500; https://doi.org/10.3390/cryst11121500 - 02 Dec 2021
Cited by 2 | Viewed by 2670
Abstract
In this work, we synthesized two new s-triazine incorporates pyrazole/piperidine/aniline moieties. Molecular structure investigations in the light of X-ray crystallography combined with Hirshfeld and DFT calculations were presented. Intermolecular interactions controlling the molecular packing of 4-(3,5-dimethyl-1H-pyrazol-1-yl)-N-phenyl-6-(piperidin-1-yl)-1,3,5-triazin-2-amine; 5a and [...] Read more.
In this work, we synthesized two new s-triazine incorporates pyrazole/piperidine/aniline moieties. Molecular structure investigations in the light of X-ray crystallography combined with Hirshfeld and DFT calculations were presented. Intermolecular interactions controlling the molecular packing of 4-(3,5-dimethyl-1H-pyrazol-1-yl)-N-phenyl-6-(piperidin-1-yl)-1,3,5-triazin-2-amine; 5a and N-(4-bromophenyl)-4-(3,5-dimethyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)-1,3,5-triazin-2-amine; 5b were analyzed using Hirshfeld calculations. The most dominant interactions are the H...H, N...H and H...C contacts in both compounds. The N...H and H...C interactions in 5a and the N...H, Br...H and H...H interactions in 5b are the most important. In addition, DFT calculations were used to compute the molecular structures of 5a and 5b; then, their electronic properties, as well as the 1H- and 13C-NMR spectra, were predicted. Both compounds are polar where 5a (1.018 Debye) has lower dipole moment than 5b (4.249 Debye). The NMR chemical shifts were calculated and very good correlations between the calculated and experimental data were obtained (R2 = 0.938–0.997). Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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12 pages, 2086 KiB  
Article
Chitosan/Selenium Nanoparticles Attenuate Diclofenac Sodium-Induced Testicular Toxicity in Male Rats
by Samy M. El-Megharbel, Fawziah A. Al-Salmi, Sarah Al-Harthi, Khadeejah Alsolami and Reham Z. Hamza
Crystals 2021, 11(12), 1477; https://doi.org/10.3390/cryst11121477 - 28 Nov 2021
Cited by 16 | Viewed by 2438
Abstract
The detrimental effect of diclofenac sodium (Diclo-Na) on male reproductive organs is reported upon in this paper. Chitosan is a polysaccharide composed of various amounts of glucosamine. Chitosan nanoparticles (CH-NPs) have attracted much attention owing to their biomedical activity. Selenium (Se) has a [...] Read more.
The detrimental effect of diclofenac sodium (Diclo-Na) on male reproductive organs is reported upon in this paper. Chitosan is a polysaccharide composed of various amounts of glucosamine. Chitosan nanoparticles (CH-NPs) have attracted much attention owing to their biomedical activity. Selenium (Se) has a vital role in nutrition, plays an important role in enhancing male reproduction, and has a wide range of free radical scavenging activities. However, the study of the impact of chitosan nanoparticles in combination with Se (IV) (CH-NPs/Se) on male reproductive toxicity associated with Diclo-Na administration is lacking in recent literature. The current study assessed the ameliorative effects of complexes of CH-NPs/Se (IV) on Diclo-Na and the ways in which they alter reproductive toxicity in male rats. Male rats were treated for 30 days successively, either with Diclo-Na (10 mg/kg) or co-treated with a CH-NPs/Se complex (280 mg/kg). Sperm characteristics, marker enzymes of testicular function, LH, FSH, and testosterone were evaluated in addition to oxidative stress markers and histological alterations. CH-NPs/Se significantly alleviated Diclo-Na-induced decline in sperm count and motility, testicular function enzymes, and levels of LH and testosterone in serum. Additionally, CH-NPs/Se co-administration at 280 mg/Kg, inhibited the Diclo-Na-induced decline of antioxidant enzyme activities and elevated oxidative stress indices and reactive free radicals in testicular homogenates of male rats. CH-NPs/Se (280 mg/kg) alone improved Diclo-Na and ameliorated histological damages in exposed rats. In conclusion, chitosan improved testicular function in Diclo-Na-treated rats by enhancing the testosterone hormone levels, ameliorating testicular tissue, and inhibiting markers of oxidative stress in male rats. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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12 pages, 3245 KiB  
Article
One Pot Ultrasonic Assisted {[Ni(tptz)Cl(H2O)2][Ni(tptz)(H2O)3]}-3Cl.5H2O Complex Formation Using Triazine Ligand, XRD/HSA-Interactions, and Spectral and Thermal Investigation
by Abeer A. AlObaid, Ahmed Boshaala, Younis O. Ben Amer, Abrahem F. Abrahem, Nabil Al-Zaqri, Mohammed Suleiman, Abdelkader Zarrouk, Nawaf Al-Maharik, Hussien A. Khamees and Ismail Warad
Crystals 2021, 11(12), 1474; https://doi.org/10.3390/cryst11121474 - 27 Nov 2021
Viewed by 1950
Abstract
Under room temperature ultrasonic conditions, mixing the neutral 2,4,6-tri(pyridin-2-yl)-1,3,5-triazine (tptz) ligand with Ni(II) salt resulted in the preparation of a unique {[Ni(tptz)Cl(H2O)2]-[Ni(tptz)(H2O)3]}3Cl.5H2O complex with two different nickel(II) centers in a high yield. The [...] Read more.
Under room temperature ultrasonic conditions, mixing the neutral 2,4,6-tri(pyridin-2-yl)-1,3,5-triazine (tptz) ligand with Ni(II) salt resulted in the preparation of a unique {[Ni(tptz)Cl(H2O)2]-[Ni(tptz)(H2O)3]}3Cl.5H2O complex with two different nickel(II) centers in a high yield. The crystal structure of {[Ni(tptz)Cl(H2O)2][Ni(tptz)(H2O)3]}3Cl.5H2O revealed the existence of distorted octahedral around both Ni(II) centers. The complex structure was further supported by FT-IR, UV-Vis., CHN-EA, TGA and EDX. The computed HSA was also performed to support the XRD interaction types. The existence of the H2O molecules in the crystal lattice was examined by FT-IR and TG/DTG measurements that proved the presence of coordinated and uncoordinated water molecules. Moreover, the thermal stability of the desired complex was evaluated at open atmosphere via TG/DTG and showed stability up to ~400 °C and multistep thermal decomposition. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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16 pages, 4298 KiB  
Article
Evaluation of Strength and Microstructural Properties of Heat Treated High-Molybdenum Content Maraging Steel
by Asiful H. Seikh, Hossam Halfa and Mahmoud S. Soliman
Crystals 2021, 11(12), 1446; https://doi.org/10.3390/cryst11121446 - 24 Nov 2021
Cited by 6 | Viewed by 2276
Abstract
Effect of high molybdenum content ~10% as an alloying element on the strength and microstructural properties of 11% nickel—1.25% titanium maraging steel was evaluated. To increase the homogeneity and cleanliness of produced ingot, the investigated steel sample was produced by melting the raw [...] Read more.
Effect of high molybdenum content ~10% as an alloying element on the strength and microstructural properties of 11% nickel—1.25% titanium maraging steel was evaluated. To increase the homogeneity and cleanliness of produced ingot, the investigated steel sample was produced by melting the raw material in an open-air induction melting furnace followed by refining utilizing a direct current electro-slag refining machine. The produced steel samples were both forged and heat-treated in optimum condition to acquire the full capacity of mechanical properties especially the tensile properties. After Forging and heat treatment at optimum condition, steel samples were evaluated by optical microscopy (OM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) analysis, electron backscattering diffraction (EBSD), and transmission electron microscopy (TEM). The experimental data showed that this steel sample has ultimate strength ~2100 MPa and elongation around 14%. High tensile properties obtained may be attributed on one hand due to the presence of high alloying lamellar martensite phase and lamellar austenite phase which has high dislocation intensity, and on the other hand, due to the high homogeneity and cleanliness of investigated samples from large nonmetallic inclusions. The results also show that a high amount of intermetallic compounds (NiMo3 and NiTi3) which are completely round and have a very low size not more than hundred nanometers. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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14 pages, 3801 KiB  
Article
Synthesis, X-ray Structure, Conformational Analysis, and DFT Studies of a Giant s-Triazine bis-Schiff Base
by Zainab M. Almarhoon, Maha I. Al-Zaben, Abir Ben Bacha, Matti Haukka, Ayman El-Faham and Saied M. Soliman
Crystals 2021, 11(11), 1418; https://doi.org/10.3390/cryst11111418 - 20 Nov 2021
Viewed by 2256
Abstract
The current work involves the synthesis of 2,2′-(6-(piperidin-1-yl)-1,3,5-triazine-2,4-diyl)bis(hydrazin-2-yl-1-ylidene))bis(methanylylidene))diphenol 4, characterization, and the DFT studies of the reported compound. The crystal unit cell parameters of 4 are a = 8.1139(2) Å, b = 11.2637(2) Å, c = 45.7836(8) Å. [...] Read more.
The current work involves the synthesis of 2,2′-(6-(piperidin-1-yl)-1,3,5-triazine-2,4-diyl)bis(hydrazin-2-yl-1-ylidene))bis(methanylylidene))diphenol 4, characterization, and the DFT studies of the reported compound. The crystal unit cell parameters of 4 are a = 8.1139(2) Å, b = 11.2637(2) Å, c = 45.7836(8) Å. The unit cell volume is 4184.28(15) Å3 and Z = 4. It crystallized in the orthorhombic crystal system and Pbca space group. The O…H, N…H, C…H, H…H and C…C intermolecular contacts which affect the crystal stability were quantitatively analyzed using Hirshfeld calculations. Their percentages were calculated to be 9.8, 15.8, 23.7, 46.4, and 1.6% from the whole contacts occurred in the crystal, respectively. Conformational analysis was performed using DFT calculations for 17 suggested conformers and the most stable conformer was found to be the one which is stabilized by two intramolecular O-H…N hydrogen bonding interactions. This conclusion was further revealed by natural bond orbital calculations. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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14 pages, 4942 KiB  
Article
Selenium/Chitosan-Folic Acid Metal Complex Ameliorates Hepatic Damage and Oxidative Injury in Male Rats Exposed to Sodium Fluoride
by Samy M. El-Megharbel, Fawziah A. Al-Salmi, Moamen S. Refat and Reham Z. Hamza
Crystals 2021, 11(11), 1354; https://doi.org/10.3390/cryst11111354 - 08 Nov 2021
Cited by 11 | Viewed by 1799
Abstract
Continuous exposure to sodium fluoride (NaF) imbalances the oxidative status in the body. The current study investigated the effect of the selenium/chitosan-folic (Se/chitosan-folic acid) novel metal complex on oxidative injury and tissue damage in the hepatic tissues of male rats exposed to (NaF). [...] Read more.
Continuous exposure to sodium fluoride (NaF) imbalances the oxidative status in the body. The current study investigated the effect of the selenium/chitosan-folic (Se/chitosan-folic acid) novel metal complex on oxidative injury and tissue damage in the hepatic tissues of male rats exposed to (NaF). Male rats received NaF (10.3 mg/kg) and Se/chitosan-folic acid (0.5 mg/Kg) orally for successive 30 days. Male rats exposed to NaF showed multi-histopathological alterations in the hepatic tissues including degenerative changes. NaF exposure elevated hepatic oxidative stress markers, lipid peroxidation, and lowered the antioxidant defense enzymes. Se/chitosan-folic acid novel complex supplementation significantly prevented hepatic injury, suppressed reactive oxygen species (ROS) generation and lipid peroxidation, and enhanced the antioxidant defense enzymes. In addition, Se/chitosan-folic acid supplementation improved the hepatic tissues of NaF-exposed male rats. In conclusion, the Se/chitosan-folic acid novel metal complex protects against NaF-induced oxidative injury and tissue injury in the hepatic tissues of male rats. The Se/chitosan-folic acid novel metal complex upregulated the hepatic tissues and enhanced the antioxidant defense enzymes in male rats. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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15 pages, 3439 KiB  
Article
Comparison of Mechanical and Microstructural Properties of as-Cast Al-Cu-Mg-Ag Alloys: Room Temperature vs. High Temperature
by Muhammad Farzik Ijaz, Mahmoud S. Soliman, Ahmed S. Alasmari, Adel T. Abbas and Faraz Hussain Hashmi
Crystals 2021, 11(11), 1330; https://doi.org/10.3390/cryst11111330 - 31 Oct 2021
Cited by 7 | Viewed by 2441
Abstract
Unfolding the structure–property linkages between the mechanical performance and microstructural characteristics could be an attractive pathway to develop new single- and polycrystalline Al-based alloys to achieve ambitious high strength and fuel economy goals. A lot of polycrystalline as-cast Al-Cu-Mg-Ag alloy systems fabricated by [...] Read more.
Unfolding the structure–property linkages between the mechanical performance and microstructural characteristics could be an attractive pathway to develop new single- and polycrystalline Al-based alloys to achieve ambitious high strength and fuel economy goals. A lot of polycrystalline as-cast Al-Cu-Mg-Ag alloy systems fabricated by conventional casting techniques have been reported to date. However, no one has reported a comparison of mechanical and microstructural properties that simultaneously incorporates the effects of both alloy chemistry and mechanical testing environments for the as-cast Al-Cu-Mg-Ag alloy systems. This preliminary prospective paper presents the examined experimental results of two alloys (denoted Alloy 1 and Alloy 2), with constant Cu content of ~3 wt.%, Cu/Mg ratios of 12.60 and 6.30, and a constant Ag of 0.65 wt.%, and correlates the synergistic comparison of mechanical properties at room and elevated temperatures. According to experimental results, the effect of the precipitation state and the mechanical properties showed strong dependence on the composition and testing environments for peak-aged, heat-treated specimens. In the room-temperature mechanical testing scenario, the higher Cu/Mg ratio alloy with Mg content of 0.23 wt.% (Alloy 1) possessed higher ultimate tensile strength when compared to the low Cu/Mg ratio with Mg content of 0.47 wt.% (Alloy 2). From phase constitution analysis, it is inferred that the increase in strength for Alloy 1 under room-temperature tensile testing is mainly ascribable to the small grain size and fine and uniform distribution of θ precipitates, which provided a barrier to slip by deaccelerating the dislocation movement in the room-temperature environment. Meanwhile, Alloy 2 showed significantly less degradation of mechanical strength under high-temperature tensile testing. Indeed, in most cases, low Cu/Mg ratios had a strong influence on the copious precipitation of thermally stable omega phase, which is known to be a major strengthening phase at elevated temperatures in the Al-Cu-Mg-Ag alloying system. Consequently, it is rationally suggested that in the high-temperature testing scenario, the improvement in mechanical and/or thermal stability in the case of the Alloy 2 specimen was mainly due to its compositional design. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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19 pages, 54589 KiB  
Article
One-Step Multi-Doping Process for Producing Effective Zinc Oxide Nanofibers to Remove Industrial Pollutants Using Sunlight
by Osama Saber, Nagih M. Shaalan, Faheem Ahmed, Shalendra Kumar and Adil Alshoaibi
Crystals 2021, 11(10), 1268; https://doi.org/10.3390/cryst11101268 - 19 Oct 2021
Cited by 8 | Viewed by 1478
Abstract
Doping processes for optical materials are one of the driving forces for developing efficient and clean technologies for decontamination of aquatic effluents through lowering their band gap energy to become effective in sunlight. The current study has used a non-conventional technique for doping [...] Read more.
Doping processes for optical materials are one of the driving forces for developing efficient and clean technologies for decontamination of aquatic effluents through lowering their band gap energy to become effective in sunlight. The current study has used a non-conventional technique for doping zinc oxide by multi metals, non-metals and organic dyes through a one-step process. In this trend, Zn-Al nanolayered structures have been used as hosts for building host–guest interactions. Organic dyes that have inorganic species of iron, nitrogen and sulfur have been used as guests in the intercalation reactions of Zn-Al layered double hydroxides. By intercalating green dyes, organic–inorganic nanohybrids were formed as nanolayered structures with expanding interlayered spacing to 2.1 nm. By changing the concentration of green dyes and thermal treatment, series of nanofibers and nanoplates of zinc oxides were formed and doped by aluminum, iron and sulfur in addition to colored species. The optical properties of the multi-doped zinc oxide indicated that it became suitable for solar applications because its band gap energy decreased from 3.30 eV to 2.80 eV. The experimental and kinetic results of the multi-doped zinc oxide concluded that the colored pollutants were effectively removed during 50 min of sunlight irradiation. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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11 pages, 3640 KiB  
Article
Synthesis, Single Crystal X-ray, Hirshfeld and DFT Studies of 1,8-Dichloro-9,10-dihydro-9,10-ethanoanthracene-11-carboxylic Acid
by Mezna Saleh Altowyan, Mujeeb A. Sultan, Saied M. Soliman, Sammer Yousuf, Israr Ali, Ihab Shawish and Assem Barakat
Crystals 2021, 11(10), 1161; https://doi.org/10.3390/cryst11101161 - 24 Sep 2021
Cited by 1 | Viewed by 2322
Abstract
In this paper, synthesis, single-crystal X-ray structure, Hirshfeld and DFT studies of 1,8-dichloro-9,10-dihydro-9,10-ethanoanthracene-11-carboxylic acid are discussed. Different intermolecular contacts affecting the crystal stability are studied using Hirshfeld calculations. The H…Cl and O…H contacts are the most significant, showing corresponding interaction distances of 2.731 [...] Read more.
In this paper, synthesis, single-crystal X-ray structure, Hirshfeld and DFT studies of 1,8-dichloro-9,10-dihydro-9,10-ethanoanthracene-11-carboxylic acid are discussed. Different intermolecular contacts affecting the crystal stability are studied using Hirshfeld calculations. The H…Cl and O…H contacts are the most significant, showing corresponding interaction distances of 2.731 Å (Cl2…H10) and 1.681Å (H1…O1), 2.328 Å (O1…H13), 2.510 Å (O1…H12) based on Hirshfeld calculations. DFT calculations are carried out to study the electronic behavior, as well as the 1H- and 13C-NMR spectra of the synthesized compound. The computed NMR chemical shifts show excellent correlation with the experimental data (R2 = 0.9884–0.9705). Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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11 pages, 2540 KiB  
Communication
Pyrrolylquinoline-BF2 and BPh2 BODIPY-Type Analogues: Synthesis, Structural Analysis and Photophysical Properties
by Abdulrahman A. Alsimaree, Omar M. Alatawi, Paul G. Waddell, David P. Day, Nawaf I. Alsenani and Julian G. Knight
Crystals 2021, 11(9), 1103; https://doi.org/10.3390/cryst11091103 - 10 Sep 2021
Cited by 3 | Viewed by 2455
Abstract
Two new pyrrolylquinoline-substituted heteroaromatic-containing compounds bearing a central boron bridge have been prepared by a short, high-yielding sequence consisting of Suzuki-coupling of 8-bromoquinoline and N-Boc 2-pyrroleboronic acid, thermolytic tert-butyloxycarbonyl deprotection, and subsequent boron chelation (either using boron trifluoride or triphenylborane). Both [...] Read more.
Two new pyrrolylquinoline-substituted heteroaromatic-containing compounds bearing a central boron bridge have been prepared by a short, high-yielding sequence consisting of Suzuki-coupling of 8-bromoquinoline and N-Boc 2-pyrroleboronic acid, thermolytic tert-butyloxycarbonyl deprotection, and subsequent boron chelation (either using boron trifluoride or triphenylborane). Both derivatives display longer wavelength absorption maxima (λabsmax) than a previously reported indolopyridine-BPh2 analogue, in agreement with the smaller HOMO-LUMO energy gap predicted by DFT quantum chemical calculations. Both of the pyrrolylquinoline-boron chelates display weak emission (quantum yields 0.3–0.9%) and the BPh2 complex displays a very broad, long-wavelength emission (λemmax = 715 nm, MeCN), which may be due to dimer emission and results in a large pseudo-Stokes’ shift (7753 cm−1) for this compound. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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10 pages, 2090 KiB  
Article
Processing and Characterization of BCZT-Modified BiFeO3-BaTiO3 Piezoelectric Ceramics
by Rizwan Ahmed Malik and Hussein Alrobei
Crystals 2021, 11(9), 1077; https://doi.org/10.3390/cryst11091077 - 06 Sep 2021
Cited by 1 | Viewed by 2357
Abstract
The synthesis of non-lead piezoelectric ceramics (1–z)(0.65Bi1.05Fe2O3-0.35BaTiO3)-z Ba(Ti0.8Zr0.2)O3-(Ba0.7Ca0.3)TiO3 using a solid state method and a quenching strategy was investigated. The processing conditions such as [...] Read more.
The synthesis of non-lead piezoelectric ceramics (1–z)(0.65Bi1.05Fe2O3-0.35BaTiO3)-z Ba(Ti0.8Zr0.2)O3-(Ba0.7Ca0.3)TiO3 using a solid state method and a quenching strategy was investigated. The processing conditions such as the sintering temperature and soaking time were optimized. The patterns of X-ray diffraction (XRD) displayed a pure perovskite structure with no secondary phases. The ferroelectric and piezoelectric characteristics of the samples were considerably improved as a result of the lattice strain. The findings of the experiment revealed that the quenching technique increases the piezoelectric sensor constant of 152 pC/N in optimized conditions. The enhanced piezoelectric sensor constant (d33) value at z = 0.020 was ascribed to the incorporation of multi-cationic BCZT, which modified the bond lengths at a unit cell level and gave rise to more flexibility in complex domain switching. This facilitated easier domain alignment in response to the applied field and resulted in an improvement in the electrical properties. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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15 pages, 4603 KiB  
Article
Synthesis of Novel Aqua ƞ4-NNNO/Cu(II) Complexes as Rapid and Selective Oxidative Catalysts for O-Catechol: Fluorescence, Spectral, Chromotropism and Thermal Analyses
by Amjad M. Shraim, Kifah S. M. Salih, Ranim E. Al-Soufi, Soaad R. Al-Mhini, Mohammad I. Ahmad and Ismail Warad
Crystals 2021, 11(9), 1072; https://doi.org/10.3390/cryst11091072 - 04 Sep 2021
Cited by 4 | Viewed by 2205
Abstract
A new tetradentate Schiff base (SB), (E)-4-fluoro-2-(1-((2-(piperazin-1-yl)ethyl)imino)ethyl)phenol, was synthesized from condensation of 2-(1-piperazinyl)ethylamine and 5-fluoro-2-hydroxyacetophenone. This ligand was coordinated with three copper(II) salts (CuCl2, CuBr2 and Cu(NO3)2⸱3H2O) separately, giving rise to new neutral water-soluble [...] Read more.
A new tetradentate Schiff base (SB), (E)-4-fluoro-2-(1-((2-(piperazin-1-yl)ethyl)imino)ethyl)phenol, was synthesized from condensation of 2-(1-piperazinyl)ethylamine and 5-fluoro-2-hydroxyacetophenone. This ligand was coordinated with three copper(II) salts (CuCl2, CuBr2 and Cu(NO3)2⸱3H2O) separately, giving rise to new neutral water-soluble Cu(II)/ƞ4-NNNO complexes (13). The new materials were fully characterized by standard spectroscopic, elemental, thermal, electronic, absorption, and fluorescence analyses. The chromotropism investigation of the aqueous solutions of the complexes revealed notable outcomes. A turn off-on halochromism effect was observed, both in the acidic and basic mediums. The green-colored solution was changed to colorless (off) upon the addition of HCl, while the initial green color was reversibly restored (on) after the addition of NaOH. On the other hand, bathochromic solvatochromism shifts were noticed in various solvents. Interestingly, complex 2 displayed a remarkable blue fluorescence shift (Δλ = 90 nm) when compared to its SB ligand. The oxidation capability of the three complexes was successfully demonstrated for the conversion of o-catechol to o-benzoquinone in aqueous solutions and in the presence of H2O2, an environmentally friendly oxidant, under mild reaction conditions. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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20 pages, 10028 KiB  
Article
X-ray Single Crystal Structure, Tautomerism Aspect, DFT, NBO, and Hirshfeld Surface Analysis of a New Schiff Bases Based on 4-Amino-5-Indol-2-yl-1,2,4-Triazole-3-Thione Hybrid
by Ahmed T. A. Boraei, Saied M. Soliman, Matti Haukka, El Sayed H. El Tamany, Abdullah Mohammed Al-Majid and Assem Barakat
Crystals 2021, 11(9), 1041; https://doi.org/10.3390/cryst11091041 - 29 Aug 2021
Cited by 4 | Viewed by 3011
Abstract
Four different new Schiff basses tethered indolyl-triazole-3-thione hybrid were designed and synthesized. X-ray single crystal structure, tautomerism, DFT, NBO and Hirshfeld analysis were explored. X-ray crystallographic investigations with the aid of Hirshfeld calculations were used to analyze the molecular packing of the studied [...] Read more.
Four different new Schiff basses tethered indolyl-triazole-3-thione hybrid were designed and synthesized. X-ray single crystal structure, tautomerism, DFT, NBO and Hirshfeld analysis were explored. X-ray crystallographic investigations with the aid of Hirshfeld calculations were used to analyze the molecular packing of the studied systems. The H···H, H···C, S···H, Br···C, O···H, C···C and N···H interactions are the most important in the molecular packing of 3. In case of 4, the S···H, N···H, S···C and C···C contacts are the most significant. The results obtained from the DFT calculations indicated that the thione tautomer is energetically lower than the thiol one by 13.9545 and 13.7464 kcal/mol for 3 and 4, respectively. Hence, the thione tautomer is the most stable one which agree with the reported X-ray structure. In addition, DFT calculations were used to compute the electronic properties while natural bond orbital calculations were used to predict the stabilization energies due to conjugation effects. Both compounds are polar where 4 (3.348 Debye) has a higher dipole moment than 3 (2.430 Debye). Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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8 pages, 736 KiB  
Article
Computational Study on the Interaction and Moving of ssDNA through Nanosheets
by Mansoor H. Alshehri
Crystals 2021, 11(9), 1019; https://doi.org/10.3390/cryst11091019 - 25 Aug 2021
Viewed by 1288
Abstract
The adsorption characteristics and moving through nanopores of a single-stranded deoxyribonucleic acid (ssDNA) molecule on monolayers, such ashexagonal boron nitride and graphene nanosheets, were studied using the continuous approach with the 6–12 Lennard–Jones potential function. The ssDNA molecule is assumed to be at [...] Read more.
The adsorption characteristics and moving through nanopores of a single-stranded deoxyribonucleic acid (ssDNA) molecule on monolayers, such ashexagonal boron nitride and graphene nanosheets, were studied using the continuous approach with the 6–12 Lennard–Jones potential function. The ssDNA molecule is assumed to be at a distance l above the sheet, and the relation between the minimum energy location and the perpendicular distance of the ssDNA molecule from the nanosheet surface is found. In addition, by assuming that there is a hole in the surface of the nanosheet as a pore, the interaction energies for the ssDNA molecule moving through the pore in the surface of the nanosheet (used to calculate the radius p of the hole) are obtained, which provides the minimum energies. Furthermore, a comparative study with graphene was performed in order to compare with hexagonal boron nitride nanosheets. Our results indicate that the binding energies of the ssDNA onto graphene and hexagonal boron nitride nanosheets are approximately 15.488 and 17.582 (kcal/mol), corresponding to perpendicular distances of l=20.271 and l=20.231 Å, respectively. In addition, we observe that the ssDNA molecule passes through graphene and hexagonal boron nitride nanopores when the gap radius p>7.5 Å. Our results provide critical insights to understand and develop the interactions and translocation of DNA molecules with and through nanosheets. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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17 pages, 5703 KiB  
Article
Diagonalization Method to Hyperbolic Two-Temperature Generalized Thermoelastic Solid Sphere under Mechanical Damage Effect
by Eman A. N. Al-Lehaibi
Crystals 2021, 11(9), 1014; https://doi.org/10.3390/cryst11091014 - 25 Aug 2021
Cited by 2 | Viewed by 1826
Abstract
This study is the first to use the diagonalization method for the new modelling of a homogeneous, thermoelastic, and isotropic solid sphere that has been subjected to mechanical damage. The fundamental equations were derived using the hyperbolic two-temperature generalized thermoelasticity theory with mechanical [...] Read more.
This study is the first to use the diagonalization method for the new modelling of a homogeneous, thermoelastic, and isotropic solid sphere that has been subjected to mechanical damage. The fundamental equations were derived using the hyperbolic two-temperature generalized thermoelasticity theory with mechanical damage taken into account. The outer surface of the sphere has been assumed to have been shocked thermally without cubical dilatation. The numerical results for the dynamical and conductive temperatures increment, strain, displacement, and average of the principal stresses components have been represented graphically with different values of the hyperbolic two-temperature parameter and mechanical damage parameters. The two-temperature model parameter and the mechanical damage parameter have significant effects. The propagations of the thermomechanical waves take place at finite speeds in the context of the hyperbolic two-temperature theory as well as in the usual context of the Lord–Shulman theory with one-temperature. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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21 pages, 7954 KiB  
Article
Comparative Study of the Sensitivity of PLA, ABS, PEEK, and PETG’s Mechanical Properties to FDM Printing Process Parameters
by Mohammed Algarni and Sami Ghazali
Crystals 2021, 11(8), 995; https://doi.org/10.3390/cryst11080995 - 21 Aug 2021
Cited by 76 | Viewed by 7833
Abstract
Significant advances in fused deposition modeling (FDM), as well as its myriad applications, have led to its growing prominence among additive manufacturing (AM) technologies. When the technology was first developed, it was used for rapid prototyping to examine and analyze a product in [...] Read more.
Significant advances in fused deposition modeling (FDM), as well as its myriad applications, have led to its growing prominence among additive manufacturing (AM) technologies. When the technology was first developed, it was used for rapid prototyping to examine and analyze a product in the design stage. FDM facilitates rapid production, requires inexpensive tools, and can fabricate complex-shaped parts; it, therefore, became popular and its use widespread. However, various FDM processing parameters have proven to affect the printed part’s mechanical properties to different extents. The values for the printing process parameters are carefully selected based on the part’s application. This study investigates the effects of four process parameters (raster angle, layer thickness, infill percentage, and printing speed) on the mechanical behavior of printed parts that are based on available literature data. These process parameter’s influence on part’s mechanical properties varies depending on the FDM material. The study focuses on four FDM materials: polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polyether ether ketone (PEEK), and polyethylene terephthalate glycol (PETG). This paper summarizes the state-of-the-art literature to show how sensitive the material’s mechanical properties are to each process parameter. The effect of each parameter on each material was quantified and ranked using analysis of variance (ANOVA). The results show that infill percentage then layer thickness are the most influential process parameter on most of the material’s mechanical properties. In addition, this work identifies gaps in existing studies and highlights opportunities for future research. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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13 pages, 6026 KiB  
Article
Synthesis and X-ray Crystal Structure of New Substituted 3-4′-Bipyrazole Derivatives. Hirshfeld Analysis, DFT and NBO Studies
by Ahmed T. A. Boraei, Matti Haukka, Ahmed A. M. Sarhan, Saied M. Soliman, Abdullah Mohammed Al-Majid and Assem Barakat
Crystals 2021, 11(8), 953; https://doi.org/10.3390/cryst11080953 - 15 Aug 2021
Viewed by 2565
Abstract
A new compounds named 3-4′-bipyrazoles 2 and 3 were synthesized in high chemical yield from a reaction of pyran-2,4-diketone 1 with aryl hydrazines under thermal conditions in MeOH. Compound 2 was unambiguously confirmed by single-crystal X-ray analysis. It crystalizes in a triclinic crystal [...] Read more.
A new compounds named 3-4′-bipyrazoles 2 and 3 were synthesized in high chemical yield from a reaction of pyran-2,4-diketone 1 with aryl hydrazines under thermal conditions in MeOH. Compound 2 was unambiguously confirmed by single-crystal X-ray analysis. It crystalizes in a triclinic crystal system and space group P-1. Its crystal structure was found to be in good agreement with the spectral characterizations. With the aid of Hirshfeld calculations, the H…H (54.8–55.3%) and H…C (28.3–29.2%) intermolecular contacts are the most dominant, while the O…H (5.8–6.5%), N…H (3.8–4.6%) and C…C (3.0–4.9%) are less dominant. The compound has a polar nature with a net dipole moment of 6.388 Debye. The BD(2)C31-C32→BD*(2)N4-C34 (27.10 kcal/mol), LP(1)N5→BD*(2)C31-C32 (36.90 kcal/mol), BD(1)C32-C34→BD*(1)C18-C31 (6.78 kcal/mol) and LP(1)N4→BD*(1)N5-C31 (7.25 kcal/mol) are the strongest π→π*, n→π*, σ-σ* and n→σ* intramolecular charge transfer processes, respectively. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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9 pages, 1623 KiB  
Article
Revisiting the Electronic Structures and Phonon Properties of Thermoelectric Antimonide-Tellurides: Spin–Orbit Coupling Induced Gap Opening in ZrSbTe and HfSbTe
by Souraya Goumri-Said, Tahani A. Alrebdi, Engin Deligoz, Haci Ozisik and Mohammed Benali Kanoun
Crystals 2021, 11(8), 917; https://doi.org/10.3390/cryst11080917 - 06 Aug 2021
Cited by 6 | Viewed by 1845
Abstract
We report theoretical studies based on density functional theory within spin-orbit coupling to explore electronic structures, lattice dynamical properties of ZrSbTe and HfSbTe. With spin−orbit coupling included, our findings reveal that ZrSbTe and HfSbTe exhibit a semiconducting behavior with narrow indirect band gaps [...] Read more.
We report theoretical studies based on density functional theory within spin-orbit coupling to explore electronic structures, lattice dynamical properties of ZrSbTe and HfSbTe. With spin−orbit coupling included, our findings reveal that ZrSbTe and HfSbTe exhibit a semiconducting behavior with narrow indirect band gaps of 0.10 eV, and 0.15 eV, respectively. Besides, the lattice dynamical properties revealed that the explored materials based on antimonide−tellurides are dynamically stable. On the basis of electronic structures, the thermoelectric properties were computed using the Landauer-Buttiker formula by considering both electron and phonon contributions in the transport properties calculation. We employed Green’s-function method based on the Green-Kubo-Mori formula, where the thermoelectric properties such as the electrical conductivity σ and thermopower α were estimated in terms of the correlation functions. The present work could be viewed as a significant amendment of the electronic nature of ZrSbTe and HfSbTe that were reported to be metallic in literature. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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22 pages, 28654 KiB  
Article
Intramolecular Hydrogen Bond, Hirshfeld Analysis, AIM; DFT Studies of Pyran-2,4-dione Derivatives
by Ahmed T. A. Boraei, Matti Haukka, Ahmed A. M. Sarhan, Saied M. Soliman and Assem Barakat
Crystals 2021, 11(8), 896; https://doi.org/10.3390/cryst11080896 - 30 Jul 2021
Cited by 9 | Viewed by 3303
Abstract
Intra and intermolecular interactions found in the developed crystals of the synthesized py-ron-2,4-dione derivatives play crucial rules in the molecular conformations and crystal stabili-ties, respectively. In this regard, Hirshfeld calculations were used to quantitatively analyze the different intermolecular interactions in the crystal structures [...] Read more.
Intra and intermolecular interactions found in the developed crystals of the synthesized py-ron-2,4-dione derivatives play crucial rules in the molecular conformations and crystal stabili-ties, respectively. In this regard, Hirshfeld calculations were used to quantitatively analyze the different intermolecular interactions in the crystal structures of some functionalized py-ran-2,4-dione derivatives. The X-ray structure of pyran-2,4-dione derivative namely (3E,3′E)-3,3′-((ethane-1,2-diylbis(azanediyl))bis(phenylmethanylylidene))bis(6-phenyl-2H-pyran-2,4(3H)-dione) was determined. It crystallized in the monoclinic crystal system and C2/c space group with unit cell parameters: a = 14.0869(4) Å, b = 20.9041(5) Å, c = 10.1444(2) Å and β = 99.687(2)°. Generally, the H…H, H…C, O…H and C…C contacts are the most important interactions in the molecular packing of the studied pyran-2,4-diones. The molecular structure of these compounds is stabilized by intramolecular O…H hydrogen bond. The nature and strength of the O…H hy-drogen bonds were analyzed using atoms in molecules calculations. In all compounds, the O…H hydrogen bond belongs to closed-shell interactions where the interaction energies are higher at the optimized geometry than the X-ray one due to the shortening in the A…H distance as a con-sequence of the geometry optimization. These compounds have polar characters with different charged regions which explored using molecular electrostatic potential map. Their natural charges, reactivity descriptors and NMR chemical shifts were computed, discussed and compared. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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13 pages, 3178 KiB  
Article
Effect of the Relative Positions of Di-Laterally Substituted Schiff Base Derivatives: Phase Transition and Computational Investigations
by Fowzia S. Alamro, Hoda A. Ahmed, Saheed A. Popoola, Hamud A. Altaleb, Khulood A. Abu Al-Ola and Sobhi M. Gomha
Crystals 2021, 11(8), 870; https://doi.org/10.3390/cryst11080870 - 27 Jul 2021
Cited by 6 | Viewed by 1525
Abstract
Two new laterally di-substituted derivatives namely, (E)-4-(((2-Chlorophenyl)imino)methyl)-3-methoxyphenyl 4-(alkoxy)benzoate, were designed and investigated for their mesomorphic properties. Elucidation of their molecular structures was carried out by elemental analyses, NMR and FT-IR, spectroscopy. Phase transitions were examined by differential scanning calorimetry (DSC) and polarized optical [...] Read more.
Two new laterally di-substituted derivatives namely, (E)-4-(((2-Chlorophenyl)imino)methyl)-3-methoxyphenyl 4-(alkoxy)benzoate, were designed and investigated for their mesomorphic properties. Elucidation of their molecular structures was carried out by elemental analyses, NMR and FT-IR, spectroscopy. Phase transitions were examined by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The optimized geometrical architectures of both compounds were deduced theoretically using GAUSSIAN 09 program. In order to establish the most probable conformation for each compound, four probable conformations were predicted for their positional isomers which vary according to the orientations of the two lateral groups. The results were used to correlate the experimental measurements with the predicted conformations. The study revealed that the investigated derivatives are non-mesomorphic and the orientations, as well as positions of the two-lateral groups, have a significant effect on the molecular packing of the molecules, their geometrical and thermal parameters. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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12 pages, 5370 KiB  
Article
Microstructure Evaluation Study of Al5083 Alloy Using EBSD Technique after Processing with Different ECAP Processes and Temperatures
by Muneer Baig, Asiful H. Seikh, Ateekh Ur Rehman, Jabair A. Mohammed, Faraz Hussain Hashmi and Sameh Mohamed Ragab
Crystals 2021, 11(8), 862; https://doi.org/10.3390/cryst11080862 - 25 Jul 2021
Cited by 3 | Viewed by 2079
Abstract
The temperature effects on the microstructural evolution of a coarse-grained Al5083 alloy during equal channel angular pressing (ECAP), were studied at ambient and high temperatures. The microstructural evaluation was done using an EBSD (electron backscattering diffraction) process. The grain refinement occurred as the [...] Read more.
The temperature effects on the microstructural evolution of a coarse-grained Al5083 alloy during equal channel angular pressing (ECAP), were studied at ambient and high temperatures. The microstructural evaluation was done using an EBSD (electron backscattering diffraction) process. The grain refinement occurred as the number of passes increased, which had a positive effect on its strength. Additionally, increasing the pressing temperature leads to a decrease in the new grain’s formation and an increase in the normal grain size in the third pass. This can be ascribed to the unwinding of strain similarity between the grains because of the continuous activity of dynamic recuperation and the grain limit sliding occurring at a higher temperature. The attainment of grain refinement is examined exhaustively in this study. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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8 pages, 453 KiB  
Article
Modeling Interactions of Iron Atoms Encapsulated in Nanotubes
by Mansoor H. Alshehri
Crystals 2021, 11(8), 845; https://doi.org/10.3390/cryst11080845 - 22 Jul 2021
Cited by 2 | Viewed by 1522
Abstract
The behavior and electronic structure of the carbon and boron nitride nanotubes that interact with the iron atom were studied using the Lennard–Jones potential and hybrid discrete-continuum approach. The iron-filled nanotubes were explored by means of classical applied mathematics in order to develop [...] Read more.
The behavior and electronic structure of the carbon and boron nitride nanotubes that interact with the iron atom were studied using the Lennard–Jones potential and hybrid discrete-continuum approach. The iron-filled nanotubes were explored by means of classical applied mathematics in order to develop an understanding of the underlying mechanisms of the encapsulation of metal atoms inside nanotubes. Herein, we examined the suction energy and then the equilibrium offset positions of the iron atoms inside zigzag and armchair single-walled nanotubes, to obtain the optimal radii of the tubes and encapsulate the iron atom by determining the radii that provide the minimum interaction energies. Our observations indicate that the encapsulation behaviour depends on the radii of the nanotubes, and we predict that it is less likely for an iron atom to be enclosed inside the nanotubes when the value of the tube radius is less than ≈2.5 Å. The optimal nanotube necessary to fully enclose the iron atom has a radius of ≈4.2 for both carbon and boron nitride nanotubes, which approximately corresponds to the interaction energies of −1.8 kcal/mol. In its entirety, this work presents an approach that might further the understanding of the encapsulation of metal atoms inside nanotubes. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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13 pages, 3513 KiB  
Article
Synthesis and Structural Characterization of Isostructural 4-(4-Aryl)-2-(5-(4-fluorophenyl)-3-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazoles
by Benson M. Kariuki, Bakr F. Abdel-Wahab and Gamal A. El-Hiti
Crystals 2021, 11(7), 795; https://doi.org/10.3390/cryst11070795 - 08 Jul 2021
Cited by 9 | Viewed by 1831
Abstract
4-(4-Chlorophenyl)-2-(5-(4-fluorophenyl)-3-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazole (4) and 4-(4-fluorophenyl)-2-(5-(4-fluorophenyl)-3-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazole (5) have been synthesized in high yields. Crystallization of 4 and 5 from dimethylformamide solvent produced samples suitable for structure determination by single crystal diffraction. The materials [...] Read more.
4-(4-Chlorophenyl)-2-(5-(4-fluorophenyl)-3-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazole (4) and 4-(4-fluorophenyl)-2-(5-(4-fluorophenyl)-3-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazole (5) have been synthesized in high yields. Crystallization of 4 and 5 from dimethylformamide solvent produced samples suitable for structure determination by single crystal diffraction. The materials are isostructural with triclinic, PĪ and symmetry and comprise two independent molecules in the asymmetric unit. The two independent molecules in the asymmetric unit assume similar conformation. The molecule is essentially planar apart from one of the two fluorophenyl groups, which is oriented roughly perpendicular to the plane of the rest of the molecule. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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22 pages, 7325 KiB  
Article
One Pot Synthesis, Surface and Magnetic Properties of Cu2O/Cu and Cu2O/CuO Nanocomposites
by Sameerah I. Al-Saeedi, Ghadah M. Al-Senani, Omar H. Abd-Elkader and Nasrallah M. Deraz
Crystals 2021, 11(7), 751; https://doi.org/10.3390/cryst11070751 - 26 Jun 2021
Cited by 21 | Viewed by 2883
Abstract
A series of copper-based systems containing two different nanocomposites (Cu2O/CuO and Cu2O/Cu) was synthesized by the egg white assisted auto-combustion route. This method was distinguished by the simplicity of its steps, low cost, one-pot synthesis process at low temperature [...] Read more.
A series of copper-based systems containing two different nanocomposites (Cu2O/CuO and Cu2O/Cu) was synthesized by the egg white assisted auto-combustion route. This method was distinguished by the simplicity of its steps, low cost, one-pot synthesis process at low temperature and, short time. The characterization of the as prepared nanocomposites was carried out by using X-ray diffraction (XRD), Fourier-transform infrared (FTIR), Scanning electron microscope (SEM) and transmission electron micrograph (TEM), Energy dispersive spectrometry (EDS) techniques. Surface and magnetic properties of the obtained systems were determined by using N2 adsorption/desorption isotherms at 77 K and the vibrating sample magnetometer (VSM) technique. XRD results confirmed the formation of Cu2O/CuO and Cu2O/Cu nanocomposites with different ratios of well crystalline CuO, Cu2O, and Cu phases. FTIR results of the combusted product displays the presence of both CuO and Cu2O, respectively. SEM/EDS and TEM results confirm the formation of a porous nanocomposite containing Cu, O, and C elements. The change in concentration of the oxygen vacancies at the surface or interface of both Cu2O/CuO and Cu2O/Cu nanoparticles resulted in different changes in their magnetization. Based on this study, it is possible to obtain nanocomposite-based copper with multiple valances by a simple and inexpensive route which can be suitable for the fabrication of different transition metal composites. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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12 pages, 1128 KiB  
Article
Synthesis, Structural Studies, and Anticancer Properties of [CuBr(PPh3)2(4,6-Dimethyl-2-Thiopyrimidine-κS]
by Bandar A. Babgi, Jalal H. Alsayari, Bambar Davaasuren, Abdul-Hamid Emwas, Mariusz Jaremko, Magda H. Abdellattif and Mostafa A. Hussien
Crystals 2021, 11(6), 688; https://doi.org/10.3390/cryst11060688 - 16 Jun 2021
Cited by 10 | Viewed by 2616
Abstract
CuBr(PPh3)2(4,6-dimethylpyrimidine-2-thione) (Cu-L) was synthesized by stirring CuBr(PPh3)3 and 4,6-dimethylpyrimidine-2-thione in dichloromethane. The crystal structure of Cu-L was obtained, and indicated that the complex adopts a distorted tetrahedral structure with several intramolecular hydrogen bonds. Moreover, a centrosymmetric [...] Read more.
CuBr(PPh3)2(4,6-dimethylpyrimidine-2-thione) (Cu-L) was synthesized by stirring CuBr(PPh3)3 and 4,6-dimethylpyrimidine-2-thione in dichloromethane. The crystal structure of Cu-L was obtained, and indicated that the complex adopts a distorted tetrahedral structure with several intramolecular hydrogen bonds. Moreover, a centrosymmetric dimer is formed by the intermolecular hydrogen bonding of the bromine acceptor created by symmetry operation 1−x, 1−y, 1−z to the methyl group (D3 = C42) of the pyrimidine–thione ligand. HSA-binding of Cu-L and its ligand were evaluated, revealing that Cu-L binds to HSA differently than its ligand. The HSA-bindings were modeled by molecular docking, which suggested that Cu-L binds to the II A domain while L binds between the I B and II A domains. Anticancer activities toward OVCAR-3 and HeLa cell lines were tested and indicated the significance of the copper center in enhancing the cytotoxic effect; negligible toxicities for L and Cu-L were observed towards a non-cancer cell line. The current study highlights the potential of copper(I)-phosphine complexes containing thione ligands as therapeutic agents. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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11 pages, 3416 KiB  
Article
Effect of Microstructure and Mechanical Properties of Al5083 Alloy Processed by ECAP at Room Temperature and High Temperature
by Muneer Baig, Ateekh Ur Rehman, Jabair A. Mohammed and Asiful H. Seikh
Crystals 2021, 11(6), 683; https://doi.org/10.3390/cryst11060683 - 14 Jun 2021
Cited by 7 | Viewed by 1970
Abstract
In this investigation, the focus is on improving the quality of the Al 5083 alloy by equal-channel angular pressing (ECAP) innovation. Equal-channel angular pressing (ECAP) is one of the best technologies for converting macro grain into ultra-fine-grained structure. Grain structure which is finer [...] Read more.
In this investigation, the focus is on improving the quality of the Al 5083 alloy by equal-channel angular pressing (ECAP) innovation. Equal-channel angular pressing (ECAP) is one of the best technologies for converting macro grain into ultra-fine-grained structure. Grain structure which is finer increases the strength of the material. In this work, a severe plastic deformation using equal-channel angular pressing (ECAP) up to 3 passes was given on Al5083 alloy using path BC at room temperature. The evolution of the microstructure was studied using an optical microscope. Tensile studies were also done. Both hardness (Vickers) and tensile strength rises as the number of passes increases; however, the ductility or the percentage of elongation increases. It can be said that the final product of this aforementioned alloy after ECAPed processing is considered to be suitable for various applications in which higher strength is required. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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9 pages, 3037 KiB  
Article
Microwave Mediated Fast Synthesis of Silver Nanoparticles and Investigation of Their Antibacterial Activities for Gram-Positive and Gram-Negative Microorganisms
by Faheem Ahmed, Suliman Yousef AlOmar, Fadwa Albalawi, Nishat Arshi, Sourabh Dwivedi, Shalendra Kumar, Nagih Mohammed Shaalan and Naushad Ahmad
Crystals 2021, 11(6), 666; https://doi.org/10.3390/cryst11060666 - 10 Jun 2021
Cited by 6 | Viewed by 2050
Abstract
Herein, a simple one-step microwave irradiation technique has been used to synthesize the silver nanoparticles using silver nitrate (AgNO3) solution and cetyltrimethyl ammonium bromide (CTAB) as a stabilizing agent. The crystals of as-prepared nanoparticles were studied using X-ray diffraction (XRD) and [...] Read more.
Herein, a simple one-step microwave irradiation technique has been used to synthesize the silver nanoparticles using silver nitrate (AgNO3) solution and cetyltrimethyl ammonium bromide (CTAB) as a stabilizing agent. The crystals of as-prepared nanoparticles were studied using X-ray diffraction (XRD) and a selected area electron diffraction (SAED) pattern, confirming the single-phase face-centered cubic structure. The optical property measured using UV-Vis spectroscopy shows an absorption maximum at 420 nm, which also confirms the formation of silver nanoparticles. Transmission electron microscopy (TEM) analysis revealed that the silver nanoparticles have a spherical shape with an average diameter of ~6 nm. The antibacterial properties of silver nanoparticles were investigated using both Gram-positive and Gram-negative microorganisms, such as Staphylococcus aureus, Pseudomonas aeruginosa, andEscherichia coli. Klebsiella pneumoniae, and Candida albicans. Results showed a highest zone of inhibition of about 35 mm against P. aeruginosa as compared with E. coli (21 mm), S. aureus (30 mm), K. pneumonia (28 mm), and C. albicans (29 mm). These studies suggested that silver nanoparticles prepared by this fast and effective method might be developed as antibacterial agents against an extensive range of microorganisms to control and stop the spreading and persistence of bacterial infections. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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16 pages, 2952 KiB  
Article
Valorization of Powder Obtained from Marble Sludge Waste and Its Suitability as a Mineral Filler
by Omrane Benjeddou and Mamdooh Alwetaishi
Crystals 2021, 11(6), 619; https://doi.org/10.3390/cryst11060619 - 31 May 2021
Cited by 4 | Viewed by 3214
Abstract
Stone industry has generated about 200 million tons of marble waste by marble processing industries whether in the form of sludge or solid blocks. The accumulated marble wastes contaminate water and air and have harmful effects on human health, plants, and animals. This [...] Read more.
Stone industry has generated about 200 million tons of marble waste by marble processing industries whether in the form of sludge or solid blocks. The accumulated marble wastes contaminate water and air and have harmful effects on human health, plants, and animals. This study focuses on exploring the uses of powder obtained by drying and grinding marble sludge waste, generated from marble manufacturing processes, as a mineral filler for other construction materials. First, physical characterization was performed on marble sludge. Second, the powder preparation process was presented. Thereafter, a set of tests was carried out to identify the chemical, mineralogical, and physical properties of marble powder. By doing so, tests such as chemical analysis, calcium carbonate content, and methylene blue test, as well as mineralogical characterization using X-ray diffraction (XRD), Atterberg limits, particle size analysis, densities, Blaine specific surface, hydraulic property, as well as reaction with admixture, cement, and activity index were conducted. In the last part of this work, the obtained powder properties are compared to the standards requirements to confirm its suitability as mineral filler. The test results showed that the obtained marble powder is too rich in calcite; it is poor of any clay minerals fraction; it is very well graded; it is not reactive; and it does not have any effects on concrete strength; consequently, it can be considered as a mineral filler. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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12 pages, 2936 KiB  
Article
Structural and Magnetic Properties Study of Fe2O3/NiO/Ni2FeO4 Nanocomposites
by Zakia Alhashem, Chawki Awada, Faheem Ahmed and Ashraf H. Farha
Crystals 2021, 11(6), 613; https://doi.org/10.3390/cryst11060613 - 29 May 2021
Cited by 9 | Viewed by 2713
Abstract
In the current work, the nanocomposites that consist chiefly of three components—α-Fe2O3, NiO and Ni2FeO4, in two different ratios 2:2:1 (FNN-221) and 2:1:1 (FNN-211), respectively—were produced. The synthesis was done in two steps by following [...] Read more.
In the current work, the nanocomposites that consist chiefly of three components—α-Fe2O3, NiO and Ni2FeO4, in two different ratios 2:2:1 (FNN-221) and 2:1:1 (FNN-211), respectively—were produced. The synthesis was done in two steps by following the chemical co-precipitation and mechanical ball-milling route. The presence of individual phase was identified from the XRD data without the detection of any additional impurities. The phase fraction of each component estimated from the profile fitting of XRD patterns were found to be 41.2%, 39.7%, 19.1% in FNN-221 sample and 49.5%, 26.4%, 24.1% for FNN-211 sample, respectively, which were consistent with the experimental values. The total magnetization at 300 K was obtained to be 13.41 emu/g and 10.95 emu/g for FNN-221 and FNN-211 samples, respectively. In FNN-211 compound the zero field coercivity (HC) expanded towards the higher field values thereby signifying the exchange bias behavior. Furthermore, the exchange bias field (Hex) for FNN-211 was obtained as 35.1 Oe. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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17 pages, 8445 KiB  
Article
π-Extended Boron Difluoride [NՈNBF2] Complex, Crystal Structure, Liquid NMR, Spectral, XRD/HSA Interactions: A DFT and TD-DFT Study
by Abdulrahman A. Alsimaree, Nawaf. I. Alsenani, Omar Mutlaq Alatawi, Abeer A. AlObaid, Julian Gary Knight, Mouslim Messali, Abdelkader Zarrouk and Ismail Warad
Crystals 2021, 11(6), 606; https://doi.org/10.3390/cryst11060606 - 27 May 2021
Cited by 2 | Viewed by 2240
Abstract
The novel tetrahedral 10-(4-carboxyphenyl)-2,8-diethyl-5,5-difluoro-1,3,7,9-tetramethyl-5H-di-pyrrolo[1,2-c:2’,1’-f][1,3,2]diazaborinin-4-ium-5-uide [NՈNBF2] BODIPY complex was prepared in a very good yield and via one-pot synthesis. The desired [NՈNBF2] has been used as a model complex for XRD/HSA interactions and DFT/B3LYP/6-311G(d,p) computations. The tetrahedral geometry around the [...] Read more.
The novel tetrahedral 10-(4-carboxyphenyl)-2,8-diethyl-5,5-difluoro-1,3,7,9-tetramethyl-5H-di-pyrrolo[1,2-c:2’,1’-f][1,3,2]diazaborinin-4-ium-5-uide [NՈNBF2] BODIPY complex was prepared in a very good yield and via one-pot synthesis. The desired [NՈNBF2] has been used as a model complex for XRD/HSA interactions and DFT/B3LYP/6-311G(d,p) computations. The tetrahedral geometry around the boron center was demonstrated by DFT optimization and XRD-crystallography. The 1H, 11B, and 19F-NMR spectra were used also to support the high symmetrical BODIPY via π-extended phenomena. Moreover, the values of the DFT-calculated structural bond lengths/angles and DFT-IR were matched to the corresponding experimental XRD and IR parameters, respectively. The crystal lattice interactions were correlated to Hirshfeld surface analysis (HSA) calculations. Calculations of the Mulliken Atomic Charge (MAC), Natural Population Analysis (NPA), Global reactivity descriptors (GRD), and Molecular Electrostatic Potential (MEP) quantum parameters were performed to support the XRD/HSA interactions result. Analysis of the predicted Density of States (DOS), molecular orbital, and time-dependent density functional theory (TD-DFT) calculations have been combined to explain the experimental UV-vis spectra and electron transfer behavior in [NՈNBF2] complex using MeOH and other four solvents. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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14 pages, 6773 KiB  
Article
Enhancement of Optical Activity and Properties of Barium Titanium Oxides to Be Active in Sunlight through Using Hollandite Phase Instead of Perovskite Phase
by Adil Alshoaibi, Osama Saber and Faheem Ahmed
Crystals 2021, 11(5), 550; https://doi.org/10.3390/cryst11050550 - 15 May 2021
Cited by 9 | Viewed by 2165
Abstract
The present study aims to enhance the optical properties of barium titanate through narrowing its band gap energy to be effective for photocatalytic reactions in sunlight and be useful for solar cells. This target was achieved through growth of the hollandite phase instead [...] Read more.
The present study aims to enhance the optical properties of barium titanate through narrowing its band gap energy to be effective for photocatalytic reactions in sunlight and be useful for solar cells. This target was achieved through growth of the hollandite phase instead of the perovskite phase inside the barium titanate crystals. By using solvent thermal reactions and thermal treatment at different temperatures (250 °C, 600 °C, and 900 °C), the hollandite phase of barium titanate was successfully obtained and confirmed through X-ray diffraction (XRD), Raman spectra and scanning electron microscopy techniques. XRD patterns showed a clear hollandite phase of barium titanium oxides for the sample calcined at 900 °C (BT1-900); however, the samples at 600 °C showed the presence of mixed phases. The mean crystallite size of the BT1-900 sample was found to be 38 nm. Morphological images revealed that the hollandite phase of barium titanate consisted of a mixed morphology of spheres and sheet-like features. The optical properties of barium titanate showed that its absorption edge shifted to the visible region and indicated band gap energy tuning ranging from 1.75 eV to 2.3 eV. Photocatalytic studies showed the complete and fast decolorization and mineralization of green pollutants (naphthol green B; NGB) in the prepared barium titanate with hollandite phase after illumination in sunlight for ten minutes. Finally, it can be concluded that the low band gap energy of barium titanate having the hollandite phase introduces beneficial structures for optical applications in sunlight. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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14 pages, 6370 KiB  
Article
Crystal Structure, Topological and Hirshfeld Surface Analysis of a Zn(II) Zwitterionic Schiff Base Complex Exhibiting Nonlinear Optical (NLO) Properties Using Z-Scan Technique
by Saima Kamaal, Mohd Mehkoom, Mohd Muslim, Syed Mohammad Afzal, Abdullah Alarifi, Mohd Afzal, Ahmad Alowais, Mohd Muddassir, Awad Naseer Albalwi and Musheer Ahmad
Crystals 2021, 11(5), 508; https://doi.org/10.3390/cryst11050508 - 04 May 2021
Cited by 14 | Viewed by 2164
Abstract
A mononuclear Zn(II) complex of (Zn(H2L) (CH3OH) Cl2) (1) has been synthesized by using a nonlinear optically active Zwitterionic Schiff base which is 4-((2-hydroxy-3-methoxybenzylidene) amino) benzoic acid (H2L). Complex 1 has been structurally [...] Read more.
A mononuclear Zn(II) complex of (Zn(H2L) (CH3OH) Cl2) (1) has been synthesized by using a nonlinear optically active Zwitterionic Schiff base which is 4-((2-hydroxy-3-methoxybenzylidene) amino) benzoic acid (H2L). Complex 1 has been structurally analyzed by FTIR and UV spectroscopy, TGA, Powder-XRD and single crystal X-ray diffraction. X-Ray crystallographic studies revealed Zn(II) complex crystallizes in a P21/c space group and exists in a distorted trigonal bipyramidal geometry (τ = 0.68). The topological analysis of complex 1 showed that the underlying net is characterized by an unknown topological type and point symbol {342.468.510}, and multilevel analysis of complex packing as dimer gives a 18-c uninodal net with unknown topological type and point symbol {348.499.56}. The calculation results of a Hirshfeld surface analysis have been investigated to explore the H-bonding within the crystal. Third-order non-linear properties were also studied, which revealed that the lower input power (5.0 mM) for the material shows full transparency; however, it becomes opaque for higher input power. Such limiting behavior of complex 1 suggests its potential for instrumental protective devices against high laser illuminations. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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14 pages, 24389 KiB  
Article
Effect of the Glycine Treatment on Synthesis and Physicochemical Characteristics of Nanosized Ni-Mn Mixed Oxides
by Ghadah M. Al-Senani, Omar H. Abd-Elkader, Nada S. Al-Kadhi and Nasrallah M. Deraz
Crystals 2021, 11(5), 487; https://doi.org/10.3390/cryst11050487 - 26 Apr 2021
Cited by 6 | Viewed by 2085
Abstract
Magnetic Ni-Mn mixed oxides based on nanoparticles (NPs) have been developed at 700 °C using a ceramic method and a glycine-assisted auto combustion path. The thermogravimetry–derivative thermogravimetry (TG—DTG), infrared radiation (IR), X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and high resolution transmittance [...] Read more.
Magnetic Ni-Mn mixed oxides based on nanoparticles (NPs) have been developed at 700 °C using a ceramic method and a glycine-assisted auto combustion path. The thermogravimetry–derivative thermogravimetry (TG—DTG), infrared radiation (IR), X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and high resolution transmittance electron micrographs (HRTEM) techniques have been used to characterize as synthesized nanomaterials by evaluating their thermal behavior, structure, distinguishing the components and establishing the morphology. A vibrating sample magnetometer has been used to estimate the magnetic properties of the materials (VSM). The analyses indicate that using a glycine-assisted auto combustion method resulted in formation of cubic spinel NiMn2O4 NPs as a single phase. The ceramic process, from the other side, led to the development of Mn2O3/NiMnO3/NiMn2O4 nanocomposite. The resulting particles being polycrystalline, including average sizes ranging from 10 to 80 nanometers. The prepared NiMn2O4 NPs showed room-temperature ferromagnetism, with an optimal saturation magnetization value of 5.0216 emu/g, according to the magnetic measurement. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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13 pages, 4822 KiB  
Article
Novel Sol-Gel Synthesis of Spherical Lead Titanate Submicrometer Powders
by Radhouane Bel-Hadj-Tahar, Mohamed Abboud, Mohd. Shkir, Abdullah Alhanash, Ali Eisa M. Anqi, Noureddine Belhadj Tahar, Mouna Bouzitoun and Mhamed Benaissa
Crystals 2021, 11(5), 484; https://doi.org/10.3390/cryst11050484 - 26 Apr 2021
Viewed by 1581
Abstract
In this study, a novel and simple synthetic sol-gel procedure was established to directly prepare spherical lead titanate powders without prior synthesis/usage of spherical templates such as TiO2 particles. Isotropic submicron particles with a mean diameter of 1–4 μm were prepared in [...] Read more.
In this study, a novel and simple synthetic sol-gel procedure was established to directly prepare spherical lead titanate powders without prior synthesis/usage of spherical templates such as TiO2 particles. Isotropic submicron particles with a mean diameter of 1–4 μm were prepared in this way. This synthetic process takes advantage of acetone as a stabilizing ligand and autogenous pressure generated in the autoclave during the reaction. The influence of various experimental factors (nature of the ligand, thermal treatment mode, and post-calcining temperature) as well as the formation mechanism were studied. Scanning electron microscopy and transmission electron microscopy were used to explore the particle morphology. The crystalline phases were explored and identified by X-ray diffraction analysis. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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16 pages, 11096 KiB  
Article
Virtual Screening and Molecular Docking Studies for Discovery of Potential RNA-Dependent RNA Polymerase Inhibitors
by Mohammed Y. Ghazwani, Ahmed H. Bakheit, Abdulrahim R. Hakami, Hamad M. Alkahtani and Abdulrahman A. Almehizia
Crystals 2021, 11(5), 471; https://doi.org/10.3390/cryst11050471 - 22 Apr 2021
Cited by 12 | Viewed by 3000
Abstract
The current COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Globally, this pandemic has affected over 111 million individuals and posed many health and economic challenges. Much research effort is dedicated to discovering new treatments to address the [...] Read more.
The current COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Globally, this pandemic has affected over 111 million individuals and posed many health and economic challenges. Much research effort is dedicated to discovering new treatments to address the associated challenges and restrict the spread of SARS-CoV-2. Since SARS-CoV-2 is a positive-strand RNA virus, its replication requires the viral RNA-dependent RNA polymerase (RdRp) enzyme. In this study, we report the discovery of new potential RdRp enzyme inhibitors based on computer modeling and simulation methodologies. The antiviral ZINC database was utilized for covalent docking virtual screening followed by molecular inter-action analyses based on reported hot spots within the RdRp binding pocket (PDB: 7BV2). Eleven molecules, ZINC000014944915, ZINC000027556215, ZINC000013556344, ZINC000003589958, ZINC000003833965, ZINC000001642252, ZINC000028525778, ZINC000027557701, ZINC000013781295, ZINC000001651128 and ZINC000013473324, were shown to have the highest binding interactions. These molecules were further assessed by molecular dynamics (MD) simu-lations and absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies. The results showed that all 11 molecules except ZINC000027557701 formed stable complexes with the viral RdRp and fell within the accepted ADMET parameters. The identified molecules can be used to design future potential RdRp inhibitors. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)
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13 pages, 3403 KiB  
Article
Encapsulated Passivation of Perovskite Quantum Dot (CsPbBr3) Using a Hot-Melt Adhesive (EVA-TPR) for Enhanced Optical Stability and Efficiency
by Saradh Prasad, Mamduh J. Aljaafreh, Mohamad S. AlSalhi and Abeer Alshammari
Crystals 2021, 11(4), 419; https://doi.org/10.3390/cryst11040419 - 13 Apr 2021
Cited by 7 | Viewed by 2701
Abstract
The notable photophysical characteristics of perovskite quantum dots (PQDs) (CsPbBr3) are suitable for optoelectronic devices. However, the performance of PQDs is unstable because of their surface defects. One way to address the instability is to passivate PQDs using different organic (polymers, [...] Read more.
The notable photophysical characteristics of perovskite quantum dots (PQDs) (CsPbBr3) are suitable for optoelectronic devices. However, the performance of PQDs is unstable because of their surface defects. One way to address the instability is to passivate PQDs using different organic (polymers, oligomers, and dendrimers) or inorganic (ZnS, PbS) materials. In this study, we performed steady-state spectroscopic investigations to measure the photoluminescence (PL), absorption (A), transmission (T), and reflectance (R) of perovskite quantum dots (CsPbBr3) and ethylene vinyl acetate/terpene phenol (1%) (EVA-TPR (1%), or EVA) copolymer/perovskite composites in thin films with a thickness of 352 ± 5 nm. EVA is highly transparent because of its large band gap; furthermore, it is inexpensive and easy to process. However, the compatibility between PQDs and EVA should be established; therefore, a series of analyses was performed to compute parameters, such as the band gap, the coefficients of absorbance and extinction, the index of refractivity, and the dielectric constant (real and imaginary parts), from the data obtained from the above investigation. Finally, the optical conductivities of the films were studied. All these analyses showed that the EVA/PQDs were more efficient and stable both physically and optically. Hence, EVA/PQDs could become copolymer/perovskite active materials suitable for optoelectronic devices, such as solar cells and perovskite/polymer light-emitting diodes (PPLEDs). Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)