The six-membered-ring azomethineN-((E)-{5-[(E)-(pyridin-3-ylimino)methyl]thiophen-2-yl}methylidene)pyridin-3-amine

2013 ◽  
Vol 69 (10) ◽  
pp. 1196-1199 ◽  
Author(s):  
Andréanne Bolduc ◽  
Stéphane Dufresne ◽  
W. G. Skene
Keyword(s):  
Energy Gap ◽  
Three Dimensional ◽  
Energy Difference ◽  
Membered Ring ◽  
Intermolecular Hydrogen Bonding ◽  
Lumo Energy ◽  
Azomethine Group ◽  
Compound C ◽  
The Mean ◽  
Homo Lumo

The title compound, C16H12N4S, forms a three-dimensional layered network structureviaintermolecular hydrogen bonding and π-stacking. The azomethine molecule adopts the thermodynamically stableEregioisomer and the pyridine substituents are antiperiplanar. The mean planes of the pyridine rings and the azomethine group to which they are connected are twisted by 27.27 (5) and 33.60 (5)°. The electrochemical energy gap of 2.3 eV based on the HOMO–LUMO energy difference is in agreement with the spectroscopically derived value.

scholarly journals 5-Methyl-1,3-phenylene bis[5-(dimethylamino)naphthalene-1-sulfonate]: crystal structure and DFT calculations

2019 ◽  
Vol 75 (7) ◽  
pp. 1079-1083
Author(s):  
Tanwawan Duangthongyou ◽  
Ramida Rattanakam ◽  
Kittipong Chainok ◽  
Songwut Suramitr ◽  
Thawatchai Tuntulani ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Energy Gap ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Hydrogen Atoms ◽  
Lumo Energy ◽  
Compound C ◽  
Dansyl Group ◽  
Weak Hydrogen Bonds ◽  
Homo Lumo

The title compound, C31H30N2S2O6, possesses crystallographically imposed twofold symmetry with the two C atoms of the central benzene ring and the C atom of its methyl substituent lying on the twofold rotation axis. The two dansyl groups are twisted away from the plane of methylphenyl bridging unit in opposite directions. The three-dimensional arrangement in the crystal is mainly stabilized by weak hydrogen bonds between the sulfonyl oxygen atoms and the hydrogen atoms from the N-methyl groups. Stacking of the dansyl group is not observed. From the DFT calculations, the HOMO–LUMO energy gap was found to be 2.99 eV and indicates n→π* and π→π* transitions within the molecule.

Direct Observation of a Lattice-Framework Silylene:  A Planar Four-Membered-Ring Dialkylsilylene with a Small HOMO−LUMO Energy Gap

2006 ◽  
Vol 25 (5) ◽  
pp. 1325-1328 ◽  
Author(s):  
Eunsang Kwon ◽  
Hiromasa Tanaka ◽  
Takayuki Makino ◽  
Shinobu Tsutsui ◽  
Shigeki Matsumoto ◽  
...  
Keyword(s):  
Direct Observation ◽  
Energy Gap ◽  
Membered Ring ◽  
Lumo Energy ◽  
Homo Lumo

Saturated N,X-Heterocyclic Carbenes (X=N, O, S, P, Si, C, and B): Stability, Nucleophilicity, and Basicity

2015 ◽  
Vol 68 (9) ◽  
pp. 1438 ◽  
Author(s):  
Zahra Azizi ◽  
Mehdi Ghambarian ◽  
Mohammad A. Rezaei ◽  
Mohammad Ghashghaee
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Energy Difference ◽  
Heterocyclic Carbenes ◽  
Structure Stability ◽  
Triplet Energy ◽  
Lumo Energy ◽  
Dft Methods ◽  
Functional Theory ◽  
Homo Lumo

Various saturated five-membered N,X-heterocyclic carbenes (X = N, O, S, P, Si, C, and B) have been studied by ab initio and density functional theory (DFT) methods. The substitutions alter the properties of the reference carbene from the viewpoint of electronic structure, stability, nucleophilicity, and basicity. Our study shows that the oxygen containing carbene (X = O) induces the highest HOMO–LUMO energy gap (ΔEHOMO–LUMO), while carbene with X = N has the widest singlet–triplet energy difference (ΔEs–t). The nucleophilicity of the carbene derivatives increased upon replacement of C, Si, and B, with the effect of the boron substituent being more pronounced. In addition, the basicity of the structure increased for the carbene derivatives with X = C and B with the latter substitution imposing a remarkably higher effect. Moreover, the substitution of boron at the α-position of the carbene increased the nucleophilicity and basicity, while inducing a reduction in the values of ΔEs–t and ΔEHOMO–LUMO.

scholarly journals Crystal structure of 13-phenyl-2,3,4,13-tetrahydro-1H-indazolo[1,2-b]phthalazine-1,6,11-trione

2015 ◽  
Vol 71 (12) ◽  
pp. o1036-o1037
Author(s):  
Esma Lamera ◽  
Saida Benzerka ◽  
Abdelmalek Bouraiou ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phenyl Ring ◽  
Three Dimensional ◽  
Phenyl Group ◽  
Ring System ◽  
Membered Ring ◽  
Dimensional Structure ◽  
Compound C ◽  
Centroid Distance ◽  
The Mean

The title compound, C21H16N2O3, consists of an indazolone moiety, bearing a phenyl group, fused to a phthalazine ring system (r.m.s. deviation = 0.018 Å). The phenyl ring is almost normal to the mean plane of the five-membered ring of the indazolone moiety, making a dihedral angle of 89.64 (7)°. The six-membered ring of the indazolone moiety has an envelope conformation, with the central methylene C atom as the flap. In the crystal, molecules are linkedviaC—H...O hydrogen bonds, forming slabs parallel to thebcplane. The slabs are linkedviaC—H...π and π–π interactions [the shortest inter-centroid distance involving rings of pyrazolophthalazine moieties is 3.6430 (8) Å], forming a three-dimensional structure.

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.

A Graph-theoretical Analysis of the HOMO-LUMO Separation in Conjugated Hydrocarbons

1974 ◽  
Vol 29 (1-2) ◽  
pp. 80-82 ◽  
Author(s):  
I. Gutman ◽  
J. V. Knop ◽  
N. Trinajstić
Keyword(s):  
Theoretical Analysis ◽  
Energy Gap ◽  
Membered Ring ◽  
Lumo Energy ◽  
Graph Theoretical Analysis ◽  
Conjugated Hydrocarbons ◽  
Homo Lumo

Graph-theoretical rules concerning the HOMO-LUMO separation in conjugated hydrocarbons are given. It has been found that a closure of odd-membered rings will not essentially change the HOMO-LUMO energy gap (ΔΕ). However, ΔΕ will be shifted down or up depending whether a (4m + 1)-or (4m + 3)-ring is closed. A closure of an even-membered ring increase the value of ΔΕ in the case of (4m + 2)- and decrease ΔΕ value in the case of (4m)-cycles if delocalized rings are formed. The effect is opposite if quinonoid rings are generated.

scholarly journals Crystal structure of 1,3-dimethyl-3-phenylpyrrolidine-2,5-dione: a clinically used anticonvulsant

2014 ◽  
Vol 70 (9) ◽  
pp. o942-o943 ◽  
Author(s):  
Carlos Ordonez ◽  
Ilia M. Pavlovetc ◽  
Victor N. Khrustalev
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Membered Ring ◽  
Framework Structure ◽  
Phenyl Substituent ◽  
Compound C ◽  
Planar Part ◽  
The Mean

In the title compound, C12H13NO2, the five-membered ring has an envelope conformation; the disubstituted C atom lies out of the mean plane through the four other ring atoms (r.m.s. deviation = 0.0038 Å) by 0.1877 (18) Å. The plane of the phenyl substituent is practically perpendicular to that of the planar part of the five-membered ring, with a dihedral angle of 87.01 (5)°. In the crystal, molecules are linked by weak C—H...O hydrogen bonds, forming inversion dimers. The dimers are linked by further C—H...O hydrogen bonds, as well as carbonyl–carbonyl attractive interactions [O...C = 3.2879 (19) Å], forming a three-dimensional framework structure.

scholarly journals Crystal structure and optical properties of fused-ring chalcone (E)-3-(anthracen-9-yl)-1-(4-nitrophenyl)prop-2-en-1-one

2019 ◽  
Vol 75 (5) ◽  
pp. 685-689 ◽  
Author(s):  
Muhamad Fikri Zaini ◽  
Ibrahim Abdul Razak ◽  
Wan Mohd Khairul ◽  
Suhana Arshad
Keyword(s):  
Close Agreement ◽  
Energy Gap ◽  
Dft Method ◽  
Ring System ◽  
Hirshfeld Surface ◽  
Lumo Energy ◽  
Compound C ◽  
Two Component ◽  
Fused Ring ◽  
Homo Lumo

The title compound, C23H15NO3, adopts an s-cis conformation with respect to the ethylene C=C and carbonyl C=O double bonds in the enone unit. The molecule is significantly twisted with a dihedral angle of 48.63 (14)° between the anthracene ring system and the benzene ring. In the crystal, molecules are linked into inversion dimers with an R 2 2(10) graph-set motif via pairs of C—H...O hydrogen bonds. The intermolecular interactions were analysed and quantified by Hirshfeld surface analysis. The molecular structure was optimized and a small HOMO–LUMO energy gap of 2.55 eV was obtained using the DFT method at the B3LYP/6–311 G++(d,p) level of theory. This value is in close agreement with the experimental value of 2.52 eV obtained from the UV–vis analysis. The crystal used was a two-component merohedral twin with a refined ratio of 0.1996 (16):0.8004 (16).

scholarly journals (11aS)-1,5,11,11a-Tetrahydro-1-benzothieno[3,2-f]indolizin-3(2H)-one

2013 ◽  
Vol 69 (12) ◽  
pp. o1819-o1820
Author(s):  
Viktor Vrábel ◽  
Július Sivý ◽  
Peter Šafář ◽  
Jozef Kožíšek
Keyword(s):  
Absolute Configuration ◽  
Structure Determination ◽  
Three Dimensional ◽  
Ring System ◽  
Membered Ring ◽  
Asymmetric Unit ◽  
Framework Structure ◽  
Compound C ◽  
The Mean ◽  
Independent Molecules

The absolute configuration of the title compound, C14H13NOS, was assigned from the synthesis and confirmed by the structure determination. There are two independent molecules in the asymmetric unit. The central six-membered ring of the indolizine moiety adopts an envelope conformation, with the greatest deviations from the mean planes being 0.569 (3) and 0.561 (3) Å for the indolizine bridgehead C atoms of the two molecules. The benzothieno ring attached to the indolizine ring system is planar to within 0.015 (3) Å in both molecules. In the crystal, weak C—H...O and C—H...π interactions lead to the formation of a three-dimensional framework structure.

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.

Sign in / Sign up

Export Citation Format

Share Document