scholarly journals Synthesis, crystal structure at 219 K and Hirshfeld surface analyses of 1,4,6-trimethylquinoxaline-2,3(1H,4H)-dione monohydrate

2020 ◽  
Vol 76 (8) ◽  
pp. 1296-1301
Author(s):  
Ayman Zouitini ◽  
Md. Serajul Haque Faizi ◽  
Younes Ouzidan ◽  
Fouad Ouazzani Chahdi ◽  
Jérôme Marrot ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Density Functional ◽  
Energy Gap ◽  
Hirshfeld Surface ◽  
Asymmetric Unit ◽  
Lumo Energy ◽  
Functional Theory ◽  
Compound C ◽  
Packing Arrangement ◽  
Homo Lumo

The asymmetric unit of the title compound, C11H12N2O2·H2O, contains a molecule of 1,4,6-trimethyl-1,4-dihydroquinoxaline-2,3-dione and a solvent water molecule. Four atoms of the benzene ring are disordered over two sets of sites in a 0.706 (7):0.294 (7) ratio while the N-bound methyl groups are rotationally disordered with occupancy ratios of 0.78 (4):0.22 (4) and 0.76 (5):0.24 (5). In the crystal, molecules are linked by O—H...O and C—H...O hydrogen bonds into layers lying parallel to (10\overline{1}). The Hirshfeld surface analysis indicates that the most important contributions to the packing arrangement are due to H...H (51.3%) and O...H/H...O (28.6%) interactions. The molecular structure calculated by density functional theory is compared with the experimentally determined molecular structure, and the HOMO–LUMO energy gap has been calculated.

scholarly journals Crystal structure, Hirshfeld surface analysis and DFT study of N-(2-amino-5-methylphenyl)-2-(5-methyl-1H-pyrazol-3-yl)acetamide

2021 ◽  
Vol 77 (6) ◽  
pp. 638-642
Author(s):  
Gamal Al Ati ◽  
Karim Chkirate ◽  
Joel T. Mague ◽  
Nadeem Abad ◽  
Redouane Achour ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Crystal Packing ◽  
Layer Structure ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Lumo Energy ◽  
Functional Theory ◽  
Homo Lumo

The title molecule, C13H16N4O, adopts an angular conformation. In the crystal a layer structure is generated by N—H...O and N—H...N hydrogen bonds together with C—H...π(ring) interactions. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (53.8%), H...C/C...H (21.7%), H...N/N...H (13.6%), and H...O/O...H (10.8%) interactions. The optimized structure calculated using density functional theory (DFT) at the B3LYP/ 6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated HOMO–LUMO energy gap is 5.0452 eV.

scholarly journals Crystal structure and DFT study of a zinc xanthate complex

2019 ◽  
Vol 75 (11) ◽  
pp. 1582-1585 ◽  
Author(s):  
Adnan M. Qadir ◽  
Sevgi Kansiz ◽  
Necmi Dege ◽  
Georgina M. Rosair ◽  
Igor O. Fritsky
Keyword(s):  
Molecular Structure ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Energy Gap ◽  
Three Dimensional ◽  
Intramolecular Interactions ◽  
Lumo Energy ◽  
Functional Theory ◽  
Homo Lumo

In the title compound, bis(2-methoxyethyl xanthato-κS)(N,N,N′,N′-tetramethylethylenediamine-κ2 N,N′)zinc(II) acetone hemisolvate, [Zn(C4H7O2S2)2(C6H16N2)]·0.5C3H6O, the ZnII ion is coordinated by two N atoms of the N,N,N′,N′-tetramethylethylenediamine ligand and two S atoms from two 2-methoxyethyl xanthate ligands. The amine ligand is disordered over two orientations and was modelled with refined occupancies of 0.538 (6) and 0.462 (6). The molecular structure features two C—H...O and two C—H...S intramolecular interactions. In the crystal, molecules are linked by weak C—H...O and C—H...S hydrogen bonds, forming a three-dimensional supramolecular architecture. The molecular structure was optimized using density functional theory (DFT) at the B3LYP/6–311 G(d,p) level. The smallest HOMO–LUMO energy gap (3.19 eV) indicates the suitability of this crystal for optoelectronic applications. The molecular electrostatic potential (MEP) further identifies the positive, negative and neutral electrostatic potential regions of the molecules. Half a molecule of disordered acetone was removed with the solvent-mask procedure in OLEX2 [Dolomanov et al. (2009). J. Appl. Cryst. 42, 339–341] and this contribition is included in the formula.

scholarly journals Crystal structure, Hirshfeld surface analysis and DFT studies of 6-bromo-3-(12-bromododecyl)-2-(4-nitrophenyl)-4H-imidazo[4,5-b]pyridine

2020 ◽  
Vol 76 (5) ◽  
pp. 677-682 ◽  
Author(s):  
Zainab Jabri ◽  
Karim Jarmoni ◽  
Tuncer Hökelek ◽  
Joel T. Mague ◽  
Safia Sabir ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Side Chain ◽  
Functional Theory ◽  
Compound C ◽  
Homo Lumo

The title compound, C24H30Br2N4O2, consists of a 2-(4-nitrophenyl)-4H-imidazo[4,5-b]pyridine entity with a 12-bromododecyl substituent attached to the pyridine N atom. The middle eight-carbon portion of the side chain is planar to within 0.09 (1) Å and makes a dihedral angle of 21.9 (8)° with the mean plane of the imidazolopyridine moiety, giving the molecule a V-shape. In the crystal, the imidazolopyridine units are associated through slipped π–π stacking interactions together with weak C—HPyr...ONtr and C—HBrmdcyl...ONtr (Pyr = pyridine, Ntr = nitro and Brmdcyl = bromododecyl) hydrogen bonds. The 12-bromododecyl chains overlap with each other between the stacks. The terminal –CH2Br group of the side chain shows disorder over two resolved sites in a 0.902 (3):0.098 (3) ratio. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H...H (48.1%), H...Br/Br...H (15.0%) and H...O/O...H (12.8%) interactions. The optimized molecular structure, using density functional theory at the B3LYP/ 6–311 G(d,p) level, is compared with the experimentally determined structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

scholarly journals Crystal structure and optical spectroscopic analyses of (E)-3-(1H-indol-2-yl)-1-(4-nitrophenyl)prop-2-en-1-one hemihydrate

2018 ◽  
Vol 74 (11) ◽  
pp. 1589-1594 ◽  
Author(s):  
Muhamad Fikri Zaini ◽  
Ibrahim Abdul Razak ◽  
Wan Mohd Khairul ◽  
Suhana Arshad
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Three Dimensional ◽  
Ring System ◽  
Hirshfeld Surface ◽  
Asymmetric Unit ◽  
Functional Theory ◽  
Spectroscopic Analyses ◽  
Dimensional Network ◽  
Homo Lumo

The asymmetric unit of the title compound, 2C17H12N2O3·H2O comprises two molecules of (E)-3-(1H-indol-2-yl)-1-(4-nitrophenyl)prop-2-en-1-one and a water molecule. The main molecule adopts an s-cis configuration with respect to the C=O and C=C bonds. The dihedral angle between the indole ring system and the nitro-substituted benzene ring is 37.64 (16)°. In the crystal, molecules are linked by O—-H...O and N—H...O hydrogen bonds, forming chains along [010]. In addition, weak C—H...O, C—H...π and π–π interactions further link the structure into a three-dimensional network. The optimized structure was generated theoretically via a density functional theory (DFT) approach at the B3LYP/6–311 G++(d,p) basis level and the HOMO–LUMO behaviour was elucidated to determine the energy gap. The obtained values of 2.70 eV (experimental) and 2.80 eV (DFT) are desirable for optoelectronic applications. The intermolecular interactions were quantified and analysed using Hirshfeld surface analysis.

scholarly journals Crystal structure of 4,4′-bis(4-bromophenyl)-1,1′,3,3′-tetrathiafulvalene

2019 ◽  
Vol 75 (8) ◽  
pp. 1195-1198 ◽  
Author(s):  
Sergei Rigin ◽  
Marina Fonari
Keyword(s):  
Title Compound ◽  
Density Functional ◽  
Energy Levels ◽  
Hirshfeld Surface ◽  
Molecular Symmetry ◽  
Lumo Energy ◽  
Functional Theory ◽  
Compound C ◽  
Phenyl Rings ◽  
Homo Lumo

The molecule of the title compound, C18H10Br2S4, has a C-shape, with C s molecular symmetry. The dihedral angle between the planes of the dithiol and phenyl rings is 8.35 (9)°. In the crystal, molecules form helical chains along [001], the shortest interactions being π...S contacts within the helices. The intermolecular interactions were investigated by Hirshfeld surface analysis. Density functional theory (DFT) was used to calculate HOMO–LUMO energy levels of the title compound and its trans isomer.

scholarly journals Crystal structure, Hirshfeld surface analysis and DFT studies of (E)-4-methyl-2-{[(4-methylphenyl)imino]methyl}phenol

2020 ◽  
Vol 76 (7) ◽  
pp. 1075-1079
Author(s):  
Nermin Kahveci Yagci ◽  
Md. Serajul Haque Faizi ◽  
Alev Sema Aydin ◽  
Necmi Dege ◽  
Onur Erman Dogan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Functional Theory ◽  
Compound C ◽  
The Density Functional Theory ◽  
Homo Lumo

In the title compound, C15H15NO, the configuration of the C=N bond of the Schiff base is E, and an intramolecular O—H...N hydrogen bond is observed, forming an intramolecular S(6) ring motif. The phenol ring is inclined by 45.73 (2)° from the plane of the aniline ring. In the crystal, molecules are linked along the b axis by O—H...N and C—H...O hydrogen bonds, forming polymeric chains. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the packing arrangement are from H...H (56.9%) and H...C/C...H (31.2%) interactions. The density functional theory (DFT) optimized structure at the B3LYP/ 6–311 G(d,p) level is compared with the experimentally determined molecular structure, and the HOMO–LUMO energy gap is provided. The crystal studied was refined as an inversion twin.

scholarly journals Crystal structure, Hirshfeld surface analysis and DFT studies of (E)-4-methyl-2-{[(2-methyl-3-nitrophenyl)imino]methyl}phenol

2020 ◽  
Vol 76 (10) ◽  
pp. 1551-1556
Author(s):  
Emine Berrin Cinar ◽  
Md. Serajul Haque Faizi ◽  
Nermin Kahveci Yagci ◽  
Onur Erman Dogan ◽  
Alev Sema Aydin ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Functional Theory ◽  
Compound C ◽  
Homo Lumo ◽  
Phenol Ring

The title compound, C15H14N2O3, was prepared by condensation of 2-hydroxy-5-methyl-benzaldehyde and 2-methyl-3-nitro-phenylamine in ethanol. The configuration of the C=N bond is E. An intramolecular O—H...N hydrogen bond is present, forming an S(6) ring motif and inducing the phenol ring and the Schiff base to be nearly coplanar [C—C—N—C torsion angle of 178.53 (13)°]. In the crystal, molecules are linked by C—H...O interactions, forming chains along the b-axis direction. The Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (37.2%), C...H (30.7%) and O...H (24.9%) interactions. The gas phase density functional theory (DFT) optimized structure at the B3LYP/ 6–311 G(d,p) level is compared to the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

scholarly journals Crystal structure, Hirshfeld surface analysis and density functional theory study of benzyl 2-oxo-1-(prop-2-yn-1-yl)-1,2-dihydroquinoline-4-carboxylate

2021 ◽  
Vol 77 (8) ◽  
pp. 824-828
Author(s):  
Younos Bouzian ◽  
Karim Chkirate ◽  
Joel T. Mague ◽  
Fares Hezam Al-Ostoot ◽  
Noureddine Hammou Ahabchane ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Lumo Energy ◽  
Functional Theory ◽  
Homo Lumo

The title molecule, C20H15NO3, adopts a Z-shaped conformation with the carboxyl group nearly coplanar with the dihydroquinoline unit. In the crystal, corrugated layers are formed by C—H...O hydrogen bonds and are stacked by C—H...π(ring) interactions. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (43.3%), H...C/C...H (26.6%) and H...O/O...H (16.3%) interactions. The optimized structure calculated using density functional theory at the B3LYP/ 6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated HOMO–LUMO energy gap is 4.0319 eV.

scholarly journals Crystal structure, Hirshfeld surface analysis and DFT studies of 4-methyl-2-({[4-(trifluoromethyl)phenyl]imino}methyl)phenol

2020 ◽  
Vol 76 (8) ◽  
pp. 1325-1330
Author(s):  
Md. Serajul Haque Faizi ◽  
Emine Berrin Cinar ◽  
Onur Erman Dogan ◽  
Alev Sema Aydin ◽  
Erbil Agar ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Functional Theory ◽  
Compound C ◽  
The Density Functional Theory ◽  
Homo Lumo

The title compound, C15H12F3NO, crystallizes with one molecule in the asymmetric unit. The configuration of the C=N bond is E and there is an intramolecular O—H...N hydrogen bond present, forming an S(6) ring motif. The dihedral angle between the mean planes of the phenol and the 4-trifluoromethylphenyl rings is 44.77 (3)°. In the crystal, molecules are linked by C—H...O interactions, forming polymeric chains extending along the a-axis direction. The Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from C...H/H...C (29.2%), H...H (28.6%), F...H/H...F (25.6%), O...H/H...O (5.7%) and F...F (4.6%) interactions. The density functional theory (DFT) optimized structure at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap. The crystal studied was refined as an inversion twin.

STRUCTURES, ABSORPTION SPECTRA, AND ELECTRONIC PROPERTIES OF POLYFLUORENE AND ITS DERIVATIVES: A THEORETICAL STUDY

2006 ◽  
Vol 05 (03) ◽  
pp. 595-608 ◽  
Author(s):  
KRIENGSAK SRIWICHITKAMOL ◽  
SONGWUT SURAMITR ◽  
POTJAMAN POOLMEE ◽  
SUPA HANNONGBUA
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Level Energy ◽  
Excitation Energies ◽  
Lumo Energy ◽  
Functional Theory ◽  
Local Energy Minimum ◽  
Pi Systems ◽  
Homo Lumo

The structural and energetic properties of polyfluorene and its derivatives were investigated, using quantum chemical calculations. Conformational analysis of bifluorene was performed by using ab initio (HF/6-31G* and MP2/6-31G*) and density functional theory (B3LYP/6-31G*) calculations. The results showed that the local energy minimum of bifluorene lies between the coplanar and perpendicular conformation, and the B3LYP/6-31G* calculations led to the overestimation of the stability of the planar pi systems. The HOMO-LUMO energy differences of fluorene oligomers and its derivatives — 9,9-dihexylfluorene (DHPF), 9,9-dioctylfluorene (PFO), and bis(2-ethylhexyl)fluorene (BEHPF) — were calculated at the B3LYP/6-31G* level. Energy gaps and effective conjugation lengths of the corresponding polymers were obtained by extrapolating HOMO-LUMO energy differences and the lowest excitation energies to infinite chain length. The lowest excitation energies and the maximum absorption wavelength of polyfluorene were also performed, employing the time-dependent density functional theory (TDDFT) and ZINDO methods. The extrapolations, based on TDDFT and ZINDO calculations, agree well with experimental results. These theoretical methods can be useful for the design of new polymeric structures with a reducing energy gap.

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