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

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.

2020 ◽  
Vol 76 (8) ◽  
pp. 1296-1301
Author(s):  
Ayman Zouitini ◽  
Md. Serajul Haque Faizi ◽  
Younes Ouzidan ◽  
Fouad Ouazzani Chahdi ◽  
Jérôme Marrot ◽  
...  

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.


Author(s):  
Gamal Al Ati ◽  
Karim Chkirate ◽  
Joel T. Mague ◽  
Nadeem Abad ◽  
Redouane Achour ◽  
...  

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.


Author(s):  
Zainab Jabri ◽  
Karim Jarmoni ◽  
Tuncer Hökelek ◽  
Joel T. Mague ◽  
Safia Sabir ◽  
...  

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.


2021 ◽  
Vol 17 ◽  
pp. 2450-2461
Author(s):  
Najeh Tka ◽  
Mohamed Adnene Hadj Ayed ◽  
Mourad Ben Braiek ◽  
Mahjoub Jabli ◽  
Peter Langer

A facile synthesis of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridine derivatives is reported which is based on POCl3-mediated cyclodehydration followed by double Suzuki–Miyaura cross-coupling. The absorption and fluorescence properties of the obtained products were investigated and their HOMO/LUMO energy levels were estimated by cyclic voltammetry measurements. Besides, density functional theory calculations were carried out for further exploration of their electronic properties.


2020 ◽  
Vol 76 (7) ◽  
pp. 1075-1079
Author(s):  
Nermin Kahveci Yagci ◽  
Md. Serajul Haque Faizi ◽  
Alev Sema Aydin ◽  
Necmi Dege ◽  
Onur Erman Dogan ◽  
...  

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.


Author(s):  
P. Periyannan ◽  
M. Beemarao ◽  
K . Karthik ◽  
S. Ponnuswamy ◽  
K. Ravichandran

In the title compound [systematic name: 1-(3-methyl-2,6-diphenylpiperidin-1-yl)ethanone], C20H23NO, the piperidine ring adopts a distorted boat conformation, while the phenyl rings subtend a dihedral angle 65.1 (2)°. In the crystal, molecules are linked by C—H...O hydrogen bonds into chains extending along the b-axis direction. The DFT/B3LYP/6–311 G(d,p) method was used to determine the HOMO–LUMO energy levels. A Hirshfeld surface analysis was conducted to verify the contributions of the different intermolecular interactions, indicating that the important contributions to the crystal packing are from H...H (73.2%), C...H (18.4%) and O...H (8.4%) interactions.


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 ◽  
...  

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.


Author(s):  
Dian Alwani Zainuri ◽  
Ibrahim Abdul Razak ◽  
Suhana Arshad

The title compound, C31H20O, was synthesized using a Claisen–Schmidt condensation. The enone group adopts an s-trans conformation and the anthracene ring systems are twisted at angles of 85.21 (19) and 83.98 (19)° from the enone plane. In the crystal, molecules are connected into chains along [100] via weak C—H...π interactions. The observed band gap of 3.03 eV is in excellent agreement with that (3.07 eV) calculated using density functional theory (DFT) at the B3LYP/6–311++G(d,p) level. The Hirshfeld surface analysis indicates a high percentage of C...H/H...C (41.2%) contacts in the crystal.


Author(s):  
P. Periyannan ◽  
M. Beemarao ◽  
K. Karthik ◽  
S. Ponnuswamy ◽  
K. Ravichandran

In the title compound, C22H27NO, the piperidine ring adopts a chair conformation. The dihedral angles between the mean plane of the piperidine ring and the phenyl rings are 89.78 (7) and 48.30 (8)°. In the crystal, molecules are linked into chains along the b-axis direction by C—H...O hydrogen bonds. The DFT/B3LYP/6–311 G(d,p) method was used to determine the HOMO–LUMO energy levels. The molecular electrostatic potential surfaces were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots were used to analyse the intermolecular interactions in the molecule.


Author(s):  
Younos Bouzian ◽  
Karim Chkirate ◽  
Joel T. Mague ◽  
Fares Hezam Al-Ostoot ◽  
Noureddine Hammou Ahabchane ◽  
...  

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.


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