Crystals

Research

15 pages, 3900 KiB

Open AccessArticle

Crystal Structure, DFT Calculation, and Hirshfeld Surface Analysis of the 1-(Cyclohex-1-en-1-yl)-3-(prop-2-yn-1-yl)-1,3-dihydro-2H-benzimidazol-2-one

by Mohamed Adardour, Marouane Ait Lahcen, Ismail Hdoufane, Mohammed M. Alanazi, Mohamed Loughzail, Hénia Mousser, Solenne Fleutot, Michel François, Driss Cherqaoui and Abdesselam Baouid

Crystals 2023, 13(12), 1661; https://doi.org/10.3390/cryst13121661 - 3 Dec 2023

Cited by 1 | Viewed by 1129

Abstract

In this paper, we describe the synthesis and structural characterization of the 1-(cyclohex-1-en-1-yl)-3-(prop-2-yn-1-yl)-1,3-dihydro-2H-benzimidazol-2-one (2) via IR, NMR (¹H and ¹³C), and HRMS. The crystal structure of the isolated organic compound 2 was confirmed through single-crystal X-ray diffraction analysis. [...] Read more.

In this paper, we describe the synthesis and structural characterization of the 1-(cyclohex-1-en-1-yl)-3-(prop-2-yn-1-yl)-1,3-dihydro-2H-benzimidazol-2-one (2) via IR, NMR (¹H and ¹³C), and HRMS. The crystal structure of the isolated organic compound 2 was confirmed through single-crystal X-ray diffraction analysis. The experimental results regarding the molecular geometry and intermolecular interactions within the crystal are in accordance with the DFT calculations and Hirshfeld surface analysis. Full article

(This article belongs to the Special Issue Density Functional Theory (DFT) and Beyond for Crystalline Materials)

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12 pages, 6854 KiB

Open AccessFeature PaperArticle

Superdense Hexagonal BP and AlP with Quartz Topology: Crystal Chemistry and DFT Study

by Vladimir L. Solozhenko and Samir F. Matar

Crystals 2023, 13(12), 1622; https://doi.org/10.3390/cryst13121622 - 22 Nov 2023

Cited by 2 | Viewed by 733

Abstract

The superdense hexagonal phosphides BP and AlP, whose structures are formed by distorted tetrahedra and characterized by quartz-derived (qtz) topology, were predicted from crystal chemistry and first principles as potential high-pressure phases. From full geometry structure relaxations and ground state energy [...] Read more.

The superdense hexagonal phosphides BP and AlP, whose structures are formed by distorted tetrahedra and characterized by quartz-derived (qtz) topology, were predicted from crystal chemistry and first principles as potential high-pressure phases. From full geometry structure relaxations and ground state energy calculations based on quantum density functional theory (DFT), qtz BP and AlP were found to be less cohesive than the corresponding cubic zinc-blende (zb) phases with diamond-like (dia) topology, but were confirmed to be mechanically (elastic constants) and dynamically (phonons) stable. From the energy–volume equations of state, qtz phases were found to be energetically favorable at small volumes (high pressures), with zb-to-qtz transition pressures of 144 GPa for BP and 28 GPa for AlP. According to the electronic band structures and the site projected density of states, both phosphides exhibit larger band gaps of the zinc-blende phases compared to the qtz phases; the smaller values for the latter result from the smaller volumes per formula unit, leading to increased covalence. Full article

(This article belongs to the Special Issue Density Functional Theory (DFT) and Beyond for Crystalline Materials)

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11 pages, 2175 KiB

Open AccessArticle

The Effects of Chlorine Doping on the Thermoelectric Properties of Bi₂O₂Se

by Buda Li, Menglu Li, Hangbo Qi, Xiaotao Zu, Liang Qiao and Haiyan Xiao

Crystals 2023, 13(11), 1586; https://doi.org/10.3390/cryst13111586 - 15 Nov 2023

Viewed by 842

Abstract

In this study, we investigate the effects of chlorine doping on the structural, electronic, and thermoelectric properties of Bi₂O₂Se by employing density functional theory combined with semiclassical Boltzmann transport theory. It is shown that chlorine doping has significant effects [...] Read more.

In this study, we investigate the effects of chlorine doping on the structural, electronic, and thermoelectric properties of Bi₂O₂Se by employing density functional theory combined with semiclassical Boltzmann transport theory. It is shown that chlorine doping has significant effects on the electronic structure and thermoelectric properties of Bi₂O₂Se. As chlorine is incorporated into the selenium sites in Bi₂O₂Se, additional electrons are acquired, thereby inducing metallic properties in chlorine-doped Bi₂O₂Se. Meanwhile, Cl doping leads to an increase in the electrical conductivity of Bi₂O₂Se at room temperature by 25 times (from 358.59

S / c m

to 9390

S / c m

), and the power factor is enhanced by a factor of 2.12 (from 4.04 mW/mK² to 12.59 mW/mK²). This study demonstrates that chlorine doping is an effective method to modify the physical properties of Bi₂O₂Se. Full article

(This article belongs to the Special Issue Density Functional Theory (DFT) and Beyond for Crystalline Materials)

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12 pages, 2373 KiB

Open AccessArticle

The Effects of Chlorine Doping on the Mechanical Properties of Bi₂O₂Se

by Buda Li, Hangbo Qi, Menglu Li, Xiaotao Zu, Liang Qiao and Haiyan Xiao

Crystals 2023, 13(10), 1492; https://doi.org/10.3390/cryst13101492 - 13 Oct 2023

Viewed by 871

Abstract

In this work, first-principle calculations based on density functional theory are employed to investigate how chlorine doping influences the elastic moduli, ductility, and lattice thermal conductivity of Bi₂O₂Se, aiming to explore an effective method to improve its mechanical properties [...] Read more.

In this work, first-principle calculations based on density functional theory are employed to investigate how chlorine doping influences the elastic moduli, ductility, and lattice thermal conductivity of Bi₂O₂Se, aiming to explore an effective method to improve its mechanical properties for its applications under thermal stress. Our findings reveal that chlorine(Cl) doping significantly affects the electronic structure and mechanical properties of Bi₂O₂Se. The electrons are distributed on the Fermi level, and the Cl-doped Bi₂O₂Se exhibits metal-like properties. In addition, Cl doping enhances the ductility and toughness of Bi₂O₂Se and reduces its lattice thermal conductivity. These results suggest that Cl doping is an effective approach for tuning the mechanical properties of Bi₂O₂Se. Full article

(This article belongs to the Special Issue Density Functional Theory (DFT) and Beyond for Crystalline Materials)

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21 pages, 9351 KiB

Open AccessArticle

Hirshfeld Surface Analysis and Density Functional Theory Calculations of 2-Benzyloxy-1,2,4-triazolo[1,5-a] quinazolin-5(4H)-one: A Comprehensive Study on Crystal Structure, Intermolecular Interactions, and Electronic Properties

by Ahmed H. Bakheit, Hatem A. Abuelizz and Rashad Al-Salahi

Crystals 2023, 13(10), 1410; https://doi.org/10.3390/cryst13101410 - 22 Sep 2023

Cited by 5 | Viewed by 1701

Abstract

This study employs a comprehensive computational analysis of the 2-benzyloxy-1,2,4-triazolo[1,5-a] quinazolin-5(4H)-one (ID code: CCDC 834498) to explore its intermolecular interactions, surface characteristics, and crystal structure. Utilizing the Hirshfeld surface technique and Crystal Explorer 17.5, the study maps the Hirshfeld [...] Read more.

This study employs a comprehensive computational analysis of the 2-benzyloxy-1,2,4-triazolo[1,5-a] quinazolin-5(4H)-one (ID code: CCDC 834498) to explore its intermolecular interactions, surface characteristics, and crystal structure. Utilizing the Hirshfeld surface technique and Crystal Explorer 17.5, the study maps the Hirshfeld surfaces for a detailed understanding of atom pair close contacts and interaction types. The study also investigates the compound’s electronic and optical characteristics using Frontier Molecular Orbital (FMO) analysis and Global Reactivity Parameters (GRPs). The compound is identified as electron-rich with strong electron-donating and accepting potential, indicating its reactivity and stability. Its band gap suggests Nonlinear Optical (NLO) attributes. The Molecular Electrostatic Potential (MEP) map reveals charge distribution across the compound’s surface. The computational methods’ reliability is validated by the low Mean Absolute Error (MAE) and Mean Squared Error (MSE) in the comparison of experimental and theoretical bond lengths and angles. Full article

(This article belongs to the Special Issue Density Functional Theory (DFT) and Beyond for Crystalline Materials)

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24 pages, 9997 KiB

Open AccessArticle

Structural Analysis and Reactivity Insights of (E)-Bromo-4-((4-((1-(4-chlorophenyl)ethylidene)amino)-5-phenyl-4H-1,2,4-triazol-3-yl)thio)-5-((2-isopropylcyclohexyl)oxy) Furan-2(5H)-one: A Combined Approach Using Single-Crystal X-ray Diffraction, Hirshfeld Surface Analysis, and Conceptual Density Functional Theory

by Ahmed H. Bakheit, Mohamed W. Attwa, Adnan A. Kadi and Hamad M. Alkahtani

Crystals 2023, 13(9), 1313; https://doi.org/10.3390/cryst13091313 - 28 Aug 2023

Cited by 3 | Viewed by 1221

Abstract

This study presents a comprehensive exploration of the structure–reactivity relationship of (E)-3-bromo-4-((4-((1-(4-chlorophenyl)ethylidene)amino)-5-phenyl-4H-1,2,4-triazol-3-yl)thio)-5-((2-isopropylcyclohexyl)oxy)furan-2(5H)-one. The study embarked on an in-depth investigation into the solid-state crystal structure of this organic compound, employing computational Density Functional Theory (DFT) and related methodologies, which have not extensively [...] Read more.

This study presents a comprehensive exploration of the structure–reactivity relationship of (E)-3-bromo-4-((4-((1-(4-chlorophenyl)ethylidene)amino)-5-phenyl-4H-1,2,4-triazol-3-yl)thio)-5-((2-isopropylcyclohexyl)oxy)furan-2(5H)-one. The study embarked on an in-depth investigation into the solid-state crystal structure of this organic compound, employing computational Density Functional Theory (DFT) and related methodologies, which have not extensively been used in the examination of such compounds. A single-crystal X-ray diffraction (SCXRD) analysis was initially performed, supplemented by a Hirshfeld surfaces analysis. This latter approach was instrumental in visualizing and quantifying intermolecular interactions within the crystal structures, offering a detailed representation of the molecule’s shape and properties within its crystalline environment. The concept of energy framework calculations was utilized to understand the varied types of energies contributing to the supramolecular architecture of the molecules within the crystal. The Conceptual DFT (CDFT) was applied to predict global reactivity descriptors and local nucleophilic/electrophilic Parr functions, providing a deeper understanding of the compound’s chemical reactivity properties. The aromatic character and π–π stacking ability were also evaluated with the help of LOLIPOP and ring aromaticity measures. This comprehensive approach not only provides a detailed description of the structure and properties of the investigated compound but also offers valuable insights into the design and development of new materials involving 1,2,4-triazole systems. Full article

(This article belongs to the Special Issue Density Functional Theory (DFT) and Beyond for Crystalline Materials)

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18 pages, 4661 KiB

Open AccessArticle

Role of Non-Covalent Interactions in Novel Supramolecular Compound, Bis(4-phenylpiperazin-1-ium) Oxalate Dihydrate: Synthesis, Molecular Structure, Thermal Characterization, Spectroscopic Properties and Quantum Chemical Study

by Mahdi Jemai, Marwa Khalfi, Noureddine Issaoui, Thierry Roisnel, Aleksandr S. Kazachenko, Omar Al-Dossary, Houda Marouani, Anna S. Kazachenko and Yuriy N. Malyar

Crystals 2023, 13(6), 875; https://doi.org/10.3390/cryst13060875 - 26 May 2023

Cited by 10 | Viewed by 1378

Abstract

The stoichiometric ratio 2:1 mix of 1-phenylpiperazine and oxalic acid dihydrate followed by slow evaporation results in a new material, bis(4-phenylpiperazin-1-ium) oxalate dihydrate, with the general chemical formula (C₁₀H₁₅N₂)₂(C₂O₄).2H₂O, [...] Read more.

The stoichiometric ratio 2:1 mix of 1-phenylpiperazine and oxalic acid dihydrate followed by slow evaporation results in a new material, bis(4-phenylpiperazin-1-ium) oxalate dihydrate, with the general chemical formula (C₁₀H₁₅N₂)₂(C₂O₄).2H₂O, indicated by PPOXH. The title compound’s asymmetric unit and three-dimensional network have been determined by single crystal X-ray diffraction. Intermolecular O-H…O, N-H…O and C-H…O hydrogen bonding assist in maintaining and stabilization of the crystal structure of this new compound. Hirshfeld surface analysis and two-dimensional fingerprints have been performed to quantify the non-covalent interactions in the PPOXH structure. The vibrational modes of the different characteristic groups of the title chemical were identified using infrared spectrum analysis. The thermal characterization of this product was studied by a coupled TG/DTA analysis. The ultraviolet-visible absorption spectrum has been used to study the optical properties and the energy gap of this compound. DFT calculations were employed to evaluate the composition and properties of PPOXH. The analysis of HOMO-LUMO frontier orbitals analysis allows us to understand the chemical reactivity of this supramolecular compound and to determine the electrophilic and nucleophilic sites responsible for electron transfer. Topological analysis (AIM), reduced density gradient (RDG), molecular electrostatic potential surface (MEPS) and Mulliken population were analyzed to evaluate the types of non-covalent interactions, localization of electrons in space, atomic charges and molecular polarity in depth. Full article

(This article belongs to the Special Issue Density Functional Theory (DFT) and Beyond for Crystalline Materials)

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10 pages, 1890 KiB

Open AccessArticle

Study of the Electronic Band Structure and Structural Stability of Al(CN)₂ and Si(CN)₂ by Density Functional Theory

by Sok-I Tam, Pak-Kin Leong, Chi-Pui Tang, Weng-Hang Leong, Toshimori Sekine, Chi-Long Tang, Kuan-Vai Tam and Kin-Tak U

Crystals 2023, 13(5), 824; https://doi.org/10.3390/cryst13050824 - 16 May 2023

Viewed by 1073

Abstract

By substituting the A site in

P 2_{1} / c

-

A {(C N)}_{2}

and varying the lattice parameters a, b, c, and the unit-cell angles, along with using crystal graph convolutional neural networks to calculate [...] Read more.

By substituting the A site in

P 2_{1} / c

-

A {(C N)}_{2}

and varying the lattice parameters a, b, c, and the unit-cell angles, along with using crystal graph convolutional neural networks to calculate their cohesive energy, the candidate compounds,

A l {(C N)}_{2}

and

S i {(C N)}_{2}

, were selected from the structure with the lowest cohesive energy. The two candidate structures were then optimized using first-principles calculations, and their phonon, electronic, and elastic properties were computed. As a result, two dynamically stable structures were found:

A l {(C N)}_{2}

with a space group of

C m c m

and

S i {(C N)}_{2}

with a space group of

R \bar{3} m

. Their phonon spectra exhibited no imaginary frequencies; thus, their elastic constants satisfied the mechanical stability criteria. Structurally,

S i {(C N)}_{2}

is similar to 6H-

S i C

and 15R-

SiC

. Its elastic constants indicated that it is harder than those

SiC

materials.

A l {(C N)}_{2}

exhibits metallic properties and the indirect wide-bandgap of

S i {(C N)}_{2}

was calculated by the generalized gradient approximation, the local density approximation, and the screened hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE06) is found to be 3.093, 3.048, and 4.589 eV, respectively. According to this wide bandgap, we can conclude that

S i {(C N)}_{2}

has the potential to be used in high-temperature and high-power environments, making it usable in a broad range of applications. Full article

(This article belongs to the Special Issue Density Functional Theory (DFT) and Beyond for Crystalline Materials)

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14 pages, 3604 KiB

Open AccessArticle

Study of the Bandgap and Crystal Structure of Cu₄TiSe₄: Theory vs. Experiment

by Grzegorz Matyszczak, Szymon Sutuła, Paweł Jóźwik, Krzysztof Krawczyk and Krzysztof Woźniak

Crystals 2023, 13(2), 331; https://doi.org/10.3390/cryst13020331 - 16 Feb 2023

Cited by 1 | Viewed by 1537

Abstract

The aim of this study was to investigate the crystal structure and bandgap of the emerging material Cu₄TiSe₄ using both theoretical and experimental methods. We synthesized the title compound via solid-state synthesis from elements. The occurrence of the single crystals [...] Read more.

The aim of this study was to investigate the crystal structure and bandgap of the emerging material Cu₄TiSe₄ using both theoretical and experimental methods. We synthesized the title compound via solid-state synthesis from elements. The occurrence of the single crystals of the Cu₄TiSe₄ compound was proven by X-ray diffraction and EDX investigations. The resolved crystal structure proves the one recently reported for this compound. Additionally, we utilized the Uspex evolutionary algorithm for the prediction of the crystal structure of the Cu₄TiSe₄ compound and to check for the presence of potential polymorphs. It turns out that Cu₄TiSe₄ may theoretically occur in three different crystal structures (space groups: I-42m (no. 121), R3m (no. 160), and P-43m (no. 215)), in which the rhombohedral phase has the lowest energy. The ab initio study of the bandgap of Cu₄TiSe₄ showed that it is indirect for each polymorphic structure and varies in the range of 1.23–1.26 eV, while experimental investigation revealed a direct transition of energy of 1.35 eV, thus showing the potential of this compound for solar cell applications. Theoretical calculations suggested that the rhombohedral phase of Cu₄TiSe₄ should exhibit a negative or relatively low (0.64 eV) bandgap. Full article

(This article belongs to the Special Issue Density Functional Theory (DFT) and Beyond for Crystalline Materials)

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