New Trends in Crystals at Saudi Arabia (Volume II)

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 2022) | Viewed by 31941

Special Issue Editors

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
Special Issues, Collections and Topics in MDPI journals
Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321, Egypt
Interests: amino acids; peptide synthesis; small bioactive molecules; pincer ligands
Special Issues, Collections and Topics in MDPI journals
Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321, Egypt
Interests: X-ray crystallography; coordination compounds; metal-based drugs; DFT; Hirshfeld; pincer ligands
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

After the success of the first volume of the Special Issue, titled “New Trends in Crystals at Saudi Arabia” (https://www.mdpi.com/journal/crystals/special_issues/King_Saud_University) (57 articles), we are pleased to announce that we are looking for papers for second volume on this topic. The original volume was mainly focused on the most important approaches for the 3D chemical structure elucidation of micro/macromolecules’ remains via single-crystal X-ray crystallography. This nondestructive 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, atom ordering, etc.

We invite researchers to contribute to the Special Issue, “New Trends in Crystals at Saudi Arabia (Volume II)”, 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.

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
Prof. Dr. Ayman El-Faham
Prof. Dr. Saied Soliman
Guest Editors

Manuscript Submission Information

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • crystal and molecular structure
  • coordination complexes
  • heterocyclic molecules
  • new ligands
  • computational study
  • bioactive compounds
  • natural products
  • nanomaterials
  • MOFs
  • crystallography

Published Papers (16 papers)

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Research

10 pages, 2392 KiB  
Article
Synthesis, Characterization and Single Crystal X-ray Diffraction Analysis of Fused Triazolo/Thiadiazole Clubbed with Indole Scaffold
Crystals 2023, 13(3), 423; https://doi.org/10.3390/cryst13030423 - 01 Mar 2023
Cited by 1 | Viewed by 1971
Abstract
The present synthetic strategy involves the synthesis of indolyl-triazolo-thiadiazole heterocyclic ring systems 813 from the condensation of 4-amino-5-(1H-indol-2-yl)-3H-1,2,4-triazole-3-thione 1 with the aromatic carboxylic acid derivatives 27 in presence of POCl3 for 1 h. All [...] Read more.
The present synthetic strategy involves the synthesis of indolyl-triazolo-thiadiazole heterocyclic ring systems 813 from the condensation of 4-amino-5-(1H-indol-2-yl)-3H-1,2,4-triazole-3-thione 1 with the aromatic carboxylic acid derivatives 27 in presence of POCl3 for 1 h. All compounds were obtained in very good yields and have been well-characterized using spectroscopic techniques. Exclusively, good quality crystals from the target organic hybrid 8-(1H-indol-2-yl)-5-(p-tolyl)-[1,2,4]triazolo [3,4-b][1,3,4]thiadiazole 9 were obtained and found suitable for X-ray single crystal diffraction measurement, which is used to confirm and analyze the molecular and supramolecular structure aspects of 9. The solid-state structure of the synthesized molecule 9 agrees very well with other characterizations. The packing of 9 is dominated by the N…H, S…H, C…C and S…C non-covalent interactions, which agree with the Hirshfeld surface analysis. The percentages of these contacts are calculated to be 20.3%, 5.4%, 9.4% and 4.3%, respectively. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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12 pages, 3359 KiB  
Article
Synthesis, Characterization, DFT, and Thermogravimetric Analysis of Neutral Co(II)/Pyrazole Complex, Catalytic Activity toward Catecholase and Phenoxazinone Oxidation
Crystals 2023, 13(2), 155; https://doi.org/10.3390/cryst13020155 - 17 Jan 2023
Viewed by 1913
Abstract
The pyrazole-pyridin-2-amine, as a tridentate pyrazole ligand, and its neutral Co(II)/pyrazole complex were prepared using a direct method with a high yield. The desired pyrazole ligand and its complex were subjected to several physicochemical and thermal analyses; moreover, the DFT-like optimization of MEP, [...] Read more.
The pyrazole-pyridin-2-amine, as a tridentate pyrazole ligand, and its neutral Co(II)/pyrazole complex were prepared using a direct method with a high yield. The desired pyrazole ligand and its complex were subjected to several physicochemical and thermal analyses; moreover, the DFT-like optimization of MEP, HOMO/LUMO, and TD-DFT correlated well with their experimental relatives. Additionally, the oxidation catalytic activities of the Co(II)/pyrazole complex, such as the catecholase of catechol to o-quinone and the phenoxazinone of 2-aminophenol to 2-aminophenoxazinone, were also evaluated under mild RT conditions and atmospheric oxygen. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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10 pages, 3893 KiB  
Article
Potential Role of ‘Green’ Synthesized Titanium Dioxide Nanoparticles in Photocatalytic Applications
Crystals 2022, 12(11), 1639; https://doi.org/10.3390/cryst12111639 - 14 Nov 2022
Cited by 3 | Viewed by 1185
Abstract
Environmental sustainability is the cornerstone of the development of nanotechnology in today’s time. The synthesis of nanoparticles (NPs) based on green chemistry widely promotes this concept by minimizing the use of toxic precursors. Herein, the synthesis of titanium dioxide (TiO2) NPs [...] Read more.
Environmental sustainability is the cornerstone of the development of nanotechnology in today’s time. The synthesis of nanoparticles (NPs) based on green chemistry widely promotes this concept by minimizing the use of toxic precursors. Herein, the synthesis of titanium dioxide (TiO2) NPs is reported using Origanum majorana extract. The mode of synthesis is facile, eco-friendly, economically, applicable, and rapid. The constituent phytochemicals of the extract responsible for the formation of the nanocatalysts were identified using FTIR spectroscopy. In addition, X-ray diffraction, particle size measurements, and transmission electron microscopy were used to characterize the nanocatalysts. Moreover, the ability of TiO2 NPs to degrade rhodamine B dye under UV irradiation was also investigated. The key findings showed the marked photocatalytic property of the synthesized green TiO2 NPs, which could be potentially incorporated as a nanoscale technique in the process of water purification for human use. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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12 pages, 7159 KiB  
Article
Synthesis and Solid-State X-ray Structure of the Mononuclear Palladium(II) Complex Based on 1,2,3-Triazole Ligand
Crystals 2022, 12(10), 1335; https://doi.org/10.3390/cryst12101335 - 21 Sep 2022
Viewed by 1412
Abstract
Herein, we described the synthesis and X-ray crystal structure of the new [Pd(3)2Cl2] complex with 1,2,3-triazole-based ligand (3). In the unit cell, there are two [Pd(3)2Cl2] molecules, and the [...] Read more.
Herein, we described the synthesis and X-ray crystal structure of the new [Pd(3)2Cl2] complex with 1,2,3-triazole-based ligand (3). In the unit cell, there are two [Pd(3)2Cl2] molecules, and the asymmetric unit comprised half of this formula due to the presence of an inversion symmetry element at the Pd(II) center. The monoclinic unit cell volume is 1327.85(6) Å3, with crystal parameters of a = 10.7712(2) Å, b = 6.8500(2) Å, and c = 18.2136(6) Å, while β = 98.851(2)°. The structure comprised two trans triazole ligand units coordinated to the Pd(II) ion via one of the N-atoms of the triazole moiety. In addition, the Pd(II) is further coordinated with two trans chloride groups, where each of the trans bonds is equidistant. The crystal structure of the [Pd(3)2Cl2] complex was compared with that for free triazole ligand 3. It was found that the coordinated ligand showed less twist around the C–N bond compared to free triazole ligand 3. The molecular packing of the latter is found controlled by short O…H, N…H, C…N, and C…C interactions in addition to the short Cl…F interhalogen and π–π interactions. H…H (23.5%), Cl…H (14.4%), N…H (14.3%), and O…H (11.2%) are the most dominant contacts. In the [Pd(3)2Cl2] complex, no significant interhalogen or π–π interactions were detected. In this case, Cl…H (31.1%), H…H (16.7%), O…H (11.6%), and F…H (9.7%) are the most dominant contacts. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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12 pages, 3519 KiB  
Article
New Bioprecursor Prodrugs of Sulfadiazine: Synthesis, X-ray Structure and Hirshfeld Analysis
Crystals 2022, 12(8), 1016; https://doi.org/10.3390/cryst12081016 - 22 Jul 2022
Cited by 3 | Viewed by 1932
Abstract
Sulphonamide motif is found extensively in numerous chemotherapeutic drug candidates, it acts by stopping the production of folate inside the bacterial cell. Current research has established the synthesis and characterization of new bioprecursor prodrugs of sulfadiazine. The first prodrug, 3, was synthesized via [...] Read more.
Sulphonamide motif is found extensively in numerous chemotherapeutic drug candidates, it acts by stopping the production of folate inside the bacterial cell. Current research has established the synthesis and characterization of new bioprecursor prodrugs of sulfadiazine. The first prodrug, 3, was synthesized via the coupling of diazonium salt of sulfadiazine with ethyl acetoacetate in AcONa at 0 °C. The second prodrug, sulfadiazine-pyrazole, 5, was furnished via cyclocondensation of the hydrazono derivative, 3, and 2-pyridyl hydrazine, 4. The generated data from the X-ray analysis is interpreted and refined to obtain the crystal structure of the target compound, 5. Density functional theory (DFT) method was used to calculate the optimized geometrical parameters, electronic state (HOMO–LUMO), and the electronic properties. Moreover, Hirshfeld analysis revealed that the most important contributions to the crystal packing of the prodrug 5 are H···H, O···H and H···C contacts. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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16 pages, 4250 KiB  
Article
Efficacy of Prednisolone/Zn Metal Complex and Artemisinin Either Alone or in Combination on Lung Functions after Excessive Exposure to Electronic Cigarettes Aerosol with Assessment of Antibacterial Activity
Crystals 2022, 12(7), 972; https://doi.org/10.3390/cryst12070972 - 12 Jul 2022
Cited by 4 | Viewed by 2047
Abstract
The use of transition metal complexes as therapeutic compounds has become more and more pronounced. These complexes offer a great diversity of uses in their medicinal applications. Electronic cigarettes (ECs) are an electronic nicotine delivery system that contain aerosol (ECR). The ligation behavior [...] Read more.
The use of transition metal complexes as therapeutic compounds has become more and more pronounced. These complexes offer a great diversity of uses in their medicinal applications. Electronic cigarettes (ECs) are an electronic nicotine delivery system that contain aerosol (ECR). The ligation behavior of prednisolone, which is a synthetic steroid that is used to treat allergic diseases and asthma arthritis, and its Zn (II) metal complex were studied and characterized based on elemental analysis, molar conductance, Fourier-transform infrared (FT-IR) spectra, electronic spectra, XRD, scanning electron microscopy (SEM), energy dispersive x-ray (EDX), and transmission electron microscopy (TEM). The FT-IR spectral data revealed that PRD acts as a mono-dentate ligand via oxygen atoms of the carbonyl group. Electronic and FT-IR data revealed that the PRD/Zn (II) metal complexes have square planner geometry. Artemisinin (ART) is the active main constituent of Artemisia annua extract, and it has been demonstrated to exert an excellent antimalarial effect. The experiment was performed on 40 male mice that were divided into the following 7 groups: Control, EC group, PRD/Zn, ART, EC plus PRD/Zn, EC plus ART, and PRD plus combination of PRD/Zn and ART. Serum CRP, IL-6, and antioxidants biomarkers were determined. Pulmonary tissue histology was evaluated. When in combination with Zn administration, PRD showed potent protective effects against pulmonary biochemical alterations induced by ECR and suppressed severe oxidative stress and pulmonary structure alterations. Additionally, PRD/Zn combined with ART prevented any stress on the pulmonary tissues via antioxidant regulation, reducing inflammatory markers CRP and Il-6 and improving antioxidant enzymatic levels more than either PRD or ART alone. Therefore, PRD/Zn combined with ART produced a synergistic effect against any sort of oxidative stress and also improved the histological structure of the lung tissues. These findings are of great importance for saving pulmonary function, especially during pandemic diseases, such as during the COVID-19 pandemic. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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13 pages, 5435 KiB  
Article
Photocatalytic Degradation of Phenol Red in Water on Nb(x)/TiO2 Nanocomposites
Crystals 2022, 12(7), 911; https://doi.org/10.3390/cryst12070911 - 26 Jun 2022
Cited by 8 | Viewed by 2002
Abstract
In this paper, the photocatalytic effect of Nb(x)/TiO2 nanocomposites on the degradation of phenol red (PR) was studied. Nb(x)/TiO2 nanocomposites are fabricated by a simple sol-gel route with new experimental conditions. The structural and optical properties were determined using high transmission [...] Read more.
In this paper, the photocatalytic effect of Nb(x)/TiO2 nanocomposites on the degradation of phenol red (PR) was studied. Nb(x)/TiO2 nanocomposites are fabricated by a simple sol-gel route with new experimental conditions. The structural and optical properties were determined using high transmission electron microscopy (HRTEM), X-ray diffraction, Raman spectroscopy, photoluminescence, and UV-vis absorbance spectroscopy. Compared to pure anatase TiO2, the recently fabricated Nb(x)/TiO2 nanocomposite has a shift in the optical band edge to the visible wavelength. Consequently, it has high performance in adsorption capacity and photocatalytic activities. A time of 160 min has been observed to be suitable for mostly degradable 20 mgL−1 of phenol red on Nb(2.0)/TiO2 composite. The kinetic results were in good agreement with the first-order kinetic model at different concentrations. In addition, the results showed that the addition of Nb led to a significant degradation process. The decomposition of phenol red pollutants showed a synergistic effect of the Nb(2.0)/TiO2 nanocomposites on wastewater treatment. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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19 pages, 8220 KiB  
Article
Trimetallic Oxides/GO Composites Optimized with Carbon Ions Radiations for Supercapacitive Electrodes
Crystals 2022, 12(6), 874; https://doi.org/10.3390/cryst12060874 - 20 Jun 2022
Cited by 3 | Viewed by 1534
Abstract
Hydrothermally synthesized electrodes of Co3O4@MnO2@NiO/GO were produced for use in supercapacitors. Graphene oxide (GO) was incorporated into the nanocomposites used for electrode synthesis due to its great surface area and electrical conductivity. The synergistic alliance among these [...] Read more.
Hydrothermally synthesized electrodes of Co3O4@MnO2@NiO/GO were produced for use in supercapacitors. Graphene oxide (GO) was incorporated into the nanocomposites used for electrode synthesis due to its great surface area and electrical conductivity. The synergistic alliance among these composites and GO enhances electrode performance, life span, and stability. The structural properties obtained from the X-ray diffraction (XRD) results suggest that nanocomposites are crystalline in nature. The synergistic alliance among these composites and GO enhances electrode performance, life span, and stability. Performance assessment of these electrodes indicates that their characteristic performance was enhanced by C2+ radiation, with the uttermost performance witnessed for electrodes radiated with 5.0 × 1015 ions/cm2. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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11 pages, 7157 KiB  
Article
X-ray Structure Analyses and Biological Evaluations of a New Cd(II) Complex with S-Triazine Based Ligand
Crystals 2022, 12(6), 861; https://doi.org/10.3390/cryst12060861 - 18 Jun 2022
Cited by 6 | Viewed by 1527
Abstract
The crystal structure of a new penta-coordinated Cd(II) complex of the formula [Cd(BPMT)Br2] was presented. This Cd(II) complex was synthesized by mixing Cd(NO3)2·4H2O and 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPMT) in the presence [...] Read more.
The crystal structure of a new penta-coordinated Cd(II) complex of the formula [Cd(BPMT)Br2] was presented. This Cd(II) complex was synthesized by mixing Cd(NO3)2·4H2O and 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPMT) in the presence of KBr. It crystallized in the monoclinic crystal system and P21/n space group. The crystal parameters are a = 11.3680(8) Å, b = 11.1648(8) Å, c = 15.8593(11) Å, and β = 103.563(2)°, while the unit cell volume is 2190.6(12) Å3 and it comprised four molecules. The supramolecular structure of the [Cd(BPMT)Br2] complex is mainly controlled by the intermolecular Br∙∙∙H interactions. Hirshfeld calculations predicted the H∙∙∙H (38.1%), Br∙∙∙H (24.3%), C∙∙∙H (11.1%), and N∙∙∙H (9.5%) interactions are the most dominant. Biological evaluations for the antimicrobial and anticancer properties of the studied complex are presented. The Cd(II) complex has better anticancer and antibacterial activities than the free BPMT ligand. The anticancer activity against lung carcinoma (A-549) is higher for the former (18.64 ± 1.09 µg/mL) compared to the latter (372.79 ± 13.64 µg/mL). Additionally, the best antibacterial activity for the Cd(II) complex was found against B. subtilis. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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19 pages, 4928 KiB  
Article
Doping Zinc Oxide Nanoparticles by Magnetic and Nonmagnetic Nanocomposites Using Organic Species for Fast Removal of Industrial Pollutants from Water in UV Light
Crystals 2022, 12(6), 811; https://doi.org/10.3390/cryst12060811 - 08 Jun 2022
Cited by 1 | Viewed by 1372
Abstract
Advanced photo-active materials have attracted attention for their potential uses in water purification. In this study, a novel and facile route was used for designing nanohybrids to be valuable sources for producing effective photocatalysts for purifying water from the colored pollutants. Host-guest interaction [...] Read more.
Advanced photo-active materials have attracted attention for their potential uses in water purification. In this study, a novel and facile route was used for designing nanohybrids to be valuable sources for producing effective photocatalysts for purifying water from the colored pollutants. Host-guest interaction and intercalation reactions used long chains of hydrocarbons of n-capric acid and stearic acid to facilitate incorporation of fine particles of cobalt iron oxide nanocomposite with the internal surface of the nanolayers of Al/Zn for building nanohybrids. The thermal decomposition of the prepared nanohybrids led to formation of zinc oxide nanoparticles doped with multi-oxides of magnetic and non-magnetic dopants. These dopants created new optical centers causing a strong reduction in the band gap energy from 3.30 eV to 2.60 eV. This positive effect was confirmed by a complete removal of the dye of Naphthol green B from water after 15 min of light irradiation. Moreover, a kinetic study showed that the reaction rate of photocatalytic degradation of the pollutants was faster than that of the conventional photocatalysts. Finally, this route was effective for producing benign and fast solutions for purifying water in addition to environment-related problems. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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10 pages, 2888 KiB  
Article
Co (II) Complexes Based on the Bis-Pyrazol-S-Triazine Pincer Ligand: Synthesis, X-ray Structure Studies, and Cytotoxic Evaluation
Crystals 2022, 12(5), 741; https://doi.org/10.3390/cryst12050741 - 20 May 2022
Cited by 6 | Viewed by 1435
Abstract
Four pincer-type Co (II) complexes of the 2,4-bis (3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine ligand (L) were evaluated for their cytotoxic activities against lung and breast cancer cell lines using cell viability assay. The X-ray single crystal structure of [Co(L)(H2O)2 [...] Read more.
Four pincer-type Co (II) complexes of the 2,4-bis (3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine ligand (L) were evaluated for their cytotoxic activities against lung and breast cancer cell lines using cell viability assay. The X-ray single crystal structure of [Co(L)(H2O)2Br]Br (1) confirmed the pincer coordination behavior of the ligand L as an N-tridentate chelate. The hexa-coordination environment of Co (II) is completed by one bromide ion completing the equatorial plane of the octahedral structure and two trans water molecules at the axial positions. It crystallized in the monoclinic crystal system and P21/m space group with crystal parameters of a = 11.3170(10) Å, b = 7.4613(7) Å, c = 12.6917(12) Å and β = 95.927(3)°. Based on Hirshfeld analysis, the most dominant contacts are H…H (48.8%), Br…H (17.6%), H…C (11.2%) and O…H (10.1%), where the Br…H interactions are the most significant. The cytotoxic evaluation of the studied systems indicated that complex [Co(L)(NO3)2] (4) has the highest activity against lung (A-549) and breast (MCF-7) cell lines. In contrast, complex [Co(L)(H2O)3](ClO4)2.H2O(3) has the lowest cytotoxic activity against both cell lines. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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8 pages, 2202 KiB  
Article
Crystallographic Evidence of η1-Coordination of Bulky Aminopyridine in Halide-Containing Iron (II) Complexes
Crystals 2022, 12(5), 697; https://doi.org/10.3390/cryst12050697 - 14 May 2022
Cited by 4 | Viewed by 3865
Abstract
Reaction of N-(2,6-diisopropylphenyl)-[6-(2,4,6-triisopropylphenyl)-pyridine-2-yl]-amine (ApH) in equimolar ratio with anhydrous FeBr2 and FeI2 in tetrahydrofuran (THF) afforded, after workup in toluene, the first examples of mono(aminopyridine) Fe(II) complexes, [ApHFeBr(µ-Br)]2 (1) and [ApHFeI2(thf)] (2), [...] Read more.
Reaction of N-(2,6-diisopropylphenyl)-[6-(2,4,6-triisopropylphenyl)-pyridine-2-yl]-amine (ApH) in equimolar ratio with anhydrous FeBr2 and FeI2 in tetrahydrofuran (THF) afforded, after workup in toluene, the first examples of mono(aminopyridine) Fe(II) complexes, [ApHFeBr(µ-Br)]2 (1) and [ApHFeI2(thf)] (2), respectively. X-ray analysis shows 1 to be dimeric, whereas compound 2 is monomeric. In both cases, aminopyridine ligands show rare η1-coordination to Fe through pyridine nitrogen atom. Compound 1 exhibits intramolecular N–H⋯Br hydrogen bonds [3.363 Å] with an N–H⋯Br angle of 158.84°. Hirshfeld surface and fingerprint plots identify the significant intermolecular interactions in the crystal network. Both compounds crystallized in the monoclinic space group. For compound 1, C2/c, the cell parameters are: a  =  25.5750(5) Å, b  =  10.5150(5) Å, c = 18.9610(8) Å, β  =  97.892(5)°, V  =  5050.7(3) A3, Z  =  4. For compound 2, P21/c, the cell parameters are: a  =  10.3180(7) Å, b  =  16.1080(10) Å, c  =  18.6580(11) Å, β  =  102.038(5)°, V  = 3032.8(3) A3, Z  =  4. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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10 pages, 1077 KiB  
Article
Impact of Heating Temperature on the Crystallization, Structural, Pasting, and Hydration Properties of Pre-Gelatinized Adlay Flour and Its Implementation in Instant Porridge Product
Crystals 2022, 12(5), 689; https://doi.org/10.3390/cryst12050689 - 12 May 2022
Cited by 2 | Viewed by 1898
Abstract
Pre-gelatinization by using an autoclave is the simplest lab-scale method for preparing instant flour from adlay. The effect of heating temperatures (60 °C, 80 °C, and 100 °C) on the structural and pasting properties of pre-gelatinized adlay flour was studied. Moreover, the sensory [...] Read more.
Pre-gelatinization by using an autoclave is the simplest lab-scale method for preparing instant flour from adlay. The effect of heating temperatures (60 °C, 80 °C, and 100 °C) on the structural and pasting properties of pre-gelatinized adlay flour was studied. Moreover, the sensory acceptability of instant porridge prepared from this flour was investigated. Results showed that the shapes of starch granules of pre-gelatinized adlay flour started to disappear at a temperature of 80 °C. However, the crystallinity of the flour gelatinized at 60 °C was higher than that of flours gelatinized at other temperatures. The treatment increased water absorption, water solubility, and swelling power of pre-gelatinized adlay flour. It changed the pasting properties of pre-gelatinized adlay flour and decreased the lightness of pre-gelatinized adlay flour. Overall, the panelists preferred the instant porridge made from pre-gelatinized adlay flour prepared from 100 °C Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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10 pages, 1359 KiB  
Article
Intermolecular Interactions of 3,5-bis(4-Methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide in a Cocrystal with 1,3-bis(4-Methoxyphenyl)prop-2-en-1-one and Dimethylformamide Solvate
Crystals 2022, 12(5), 663; https://doi.org/10.3390/cryst12050663 - 05 May 2022
Cited by 4 | Viewed by 2108
Abstract
Two new multicomponent crystals consisting of 3,5-bis(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide (1) with 1,3-bis(4-methoxyphenyl)prop-2-en-1-one (2) and with dimethylformamide (DMF), both in 1:1 ratio, prepared and structurally characterized. The occurrence of 1 in different crystal structures enabled a [...] Read more.
Two new multicomponent crystals consisting of 3,5-bis(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide (1) with 1,3-bis(4-methoxyphenyl)prop-2-en-1-one (2) and with dimethylformamide (DMF), both in 1:1 ratio, prepared and structurally characterized. The occurrence of 1 in different crystal structures enabled a comparison of hydrogen bonding contacts between the two structures as well as with the known structure of pure 1. The backbone of molecule 1 was similar in the structures but the orientation of the methoxy groups varied. Molecule 1 was involved in various combinations of the possible hydrogen bonding contacts, including N–H…O=C, N–H…OMe, and N–H…S. Both N–H hydrogens in the cocrystal (12) and the solvate (1-DMF) participated in hydrogen bonding but only one hydrogen atom took part in the structure of pure 1. The S atom accepted contacts in both the structures of pure 1 and cocrystal 12 but not in that of the 1-DMF solvate. The oxygen atoms of both methoxy groups acted as acceptors in the structure of pure 1, whereas one oxygen was involved in the 1-DMF solvate and none in cocrystal 12. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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14 pages, 3575 KiB  
Article
Enhancement of the Stability of Encapsulated Pomegranate (Punica granatum L.) Peel Extract by Double Emulsion with Carboxymethyl Cellulose
Crystals 2022, 12(5), 622; https://doi.org/10.3390/cryst12050622 - 27 Apr 2022
Cited by 3 | Viewed by 2333
Abstract
Pomegranate peel enriched with high value of bioactive phenolics with valuable health benefits. However, after extraction of the phenolic compounds, diverse factors can affect their stability. Therefore, we, herein, aimed to prepare W1/O/W2 double nanoemulsions loaded with phenolic-rich extract from [...] Read more.
Pomegranate peel enriched with high value of bioactive phenolics with valuable health benefits. However, after extraction of the phenolic compounds, diverse factors can affect their stability. Therefore, we, herein, aimed to prepare W1/O/W2 double nanoemulsions loaded with phenolic-rich extract from pomegranate peel in the W1 phase. Double emulsions were fabricate during a two-step emulsification technique. Furthermore, the influence of sodium carboxymethyl cellulose (CMC) in the outer aqueous phase was also investigated. We found that W1/O/W2 emulsions containing phenolic-rich extract showed good physical stability, especially in the particle size, polydispersity index, zeta potential, and creaming index. Intriguingly, high encapsulation rates of pomegranate polyphenols >95% were achieved; however, emulsion with CMC had the best encapsulation stability during storage. Thus, our study provides helpful information about the double nanoemulsions delivery system for polyphenols generated from pomegranate peel, which may lead to the development of innovative polyphenol-enriched functional foods. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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17 pages, 38131 KiB  
Article
Synthesis, X-ray, Hirshfeld, and AIM Studies on Zn(II) and Cd(II) Complexes with Pyridine Ligands
Crystals 2022, 12(5), 590; https://doi.org/10.3390/cryst12050590 - 22 Apr 2022
Cited by 1 | Viewed by 1905
Abstract
The synthesis and crystal structures of three heteroleptic complexes of Zn(II) and Cd(II) with pyridine ligands (ethyl nicotinate (EtNic), N,N-diethylnicotinamide (DiEtNA), and 2-amino-5-picoline (2Ampic) are presented. The complex [Zn(EtNic)2Cl2] (1) showed [...] Read more.
The synthesis and crystal structures of three heteroleptic complexes of Zn(II) and Cd(II) with pyridine ligands (ethyl nicotinate (EtNic), N,N-diethylnicotinamide (DiEtNA), and 2-amino-5-picoline (2Ampic) are presented. The complex [Zn(EtNic)2Cl2] (1) showed a distorted tetrahedral coordination geometry with two EtNic ligand units and two chloride ions as monodentate ligands. Complexes [Zn(DiEtNA)(H2O)4(SO4)]·H2O (2) and [Cd(OAc)2(2Ampic)2] (3) had hexa-coordinated Zn(II) and Cd(II) centers. In the former, the Zn(II) was coordinated with three different monodentate ligands, which were DiEtNA, H2O, and SO42−. In 3, the Cd(II) ion was coordinated with two bidentate acetate ions and two monodentate 2Ampic ligand units. The supramolecular structures of the three complexes were elucidated using Hirshfeld analysis. In 1, the most important interactions that governed the molecular packing were O···H (15.5–15.6%), Cl···H (13.6–13.8%), Cl···C (6.3%), and C···H (10.3–10.6%) contacts. For complexes 2 and 3, the H···H, O···H, and C···H contacts dominated. Their percentages were 50.2%, 41.2%, and 7.1%, respectively, for 2 and 57.1%, 19.6%, and 15.2%, respectively, for 3. Only in complex 3, weak π-π stacking interactions between the stacked pyridines were found. The Zn(II) natural charges were calculated using the DFT method to be 0.8775, 1.0559, and 1.2193 for complexes 13, respectively. A predominant closed-shell character for the Zn–Cl, Zn–N, Zn–O, Cd–O, and Cd–N bonds was also concluded from an atoms in molecules (AIM) study. Full article
(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia (Volume II))
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