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.

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 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 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).

Anthracene-Based Zwitterion with a Small HOMO‒LUMO Energy Gap

Synthesis ◽  
2021 ◽  
Author(s):  
Ayane Kayama ◽  
Akihiro Shimizu ◽  
Ryo Shintani
Keyword(s):  
Electronic Structure ◽  
Dft Calculations ◽  
Light Absorption ◽  
Energy Gap ◽  
Redox Properties ◽  
Low Energy ◽  
Structure And Properties ◽  
Lumo Energy ◽  
Homo Lumo

We have designed and synthesized an anthracene-based zwitterion, 2-methyl-2-azoniaanthracene-7-olate. The zwitterion shows amphoteric redox properties and low-energy light absorption originating from the small HOMO‒LUMO energy gap of ca. 1.7 eV. DFT calculations show that the combination of replacing the C–H with N+–Me and introducing O− is necessary to alter the electronic structure and properties of anthracene significantly.

scholarly journals Theoretical insights into a colorimetric azo-based probe to detect copper ions

RSC Advances ◽  
2020 ◽  
Vol 10 (39) ◽  
pp. 23196-23202
Author(s):  
Juan Pang ◽  
Li Shu ◽  
Ming Li ◽  
Xiaohong Hu
Keyword(s):  
Dft Calculations ◽  
Energy Gap ◽  
Copper Ions ◽  
Colour Change ◽  
Amino Group ◽  
Lumo Energy ◽  
Homo Lumo

DFT calculations indicated that the rotation of the N,N-di(carboxymethyl)amino group around the N–CAr bond by approximately 90°, resulted in a larger HOMO–LUMO energy gap, and led to the observed colour change.

TDDFT study of the UV-vis spectra of subporphyrazines and subphthalocyanines

2011 ◽  
Vol 15 (11n12) ◽  
pp. 1220-1230 ◽  
Author(s):  
Al Mokhtar Lamsabhi ◽  
Manuel Yáñez ◽  
Otilia Mó ◽  
Cristina Trujillo ◽  
Fernando Blanco ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Absorption Spectra ◽  
Boron Atom ◽  
Energy Gap ◽  
Red Shift ◽  
Lumo Energy ◽  
Td Dft ◽  
Homo Lumo

The UV-vis spectra of a series of subporphyrazines, SubPz(A,R), and subphthalocyanines, SubPc(A,R) ( A = F, Cl; R = H, F, CH3, C3H7, SCH3, SC2H5 and SPh), where A is the substituent attached to the central boron atom and R is the substituent attached to the periphery of the molecule have been analyzed through the use of TD–DFT calculations in vacuum and using chloroform as a solvent. The absorption spectra depend on both, the characteristics of the substituent attached to the periphery of the molecule and the extension of the π-system on going from SubPz to the SubPc analog. These latter effects lead to a red-shift of both the Q-band and the B-band, although the effect is larger for the former, mainly due to the increase of HOMO–LUMO energy gap on going from the SubPz to the SubPc analog. The effect of the substituents R is more intricate, because the profile of the absorption spectra changes depending on whether both substituents are on the same side (uu or dd) or on opposite sides (ud) of the molecular cone. Since the three conformers are rather close in energy, the observed spectra correspond, very likely, to the sum of the spectra of all of them.

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.

A p–n fusion strategy to design bipolar organic materials for high-energy-density symmetric batteries

2021 ◽  
Author(s):  
Jihyeon Kim ◽  
Heechan Kim ◽  
Sechan Lee ◽  
Giyun Kwon ◽  
Taewon Kang ◽  
...  
Keyword(s):  
Energy Density ◽  
Organic Material ◽  
Energy Gap ◽  
High Energy ◽  
High Energy Density ◽  
Lumo Energy ◽  
Fusion Strategy ◽  
Redox Active ◽  
Bipolar Type ◽  
Homo Lumo

A new bipolar-type redox-active organic material with a wide HOMO–LUMO energy gap is designed though the ‘p–n fusion’ strategy.

scholarly journals 2-Amino-5-chloropyridinium cis-diaquadioxalatochromate(III) sesquihydrate

2012 ◽  
Vol 68 (6) ◽  
pp. m824-m825 ◽  
Author(s):  
Ichraf Chérif ◽  
Jawher Abdelhak ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Rotation Axis ◽  
Three Dimensional ◽  
Octahedral Geometry ◽  
Distorted Octahedral Geometry ◽  
Water Molecules ◽  
Lattice Water ◽  
Compound C ◽  
Hydrogen Bonding Interactions ◽  
Distorted Octahedral ◽  
Independent Lattice

In the crystal structure of the title compound, (C5H6ClN2)[Cr(C2O4)2(H2O)2]·1.5H2O, the CrIII atom adopts a distorted octahedral geometry being coordinated by two O atoms of two cis water molecules and four O atoms from two chelating oxalate dianions. The cis-diaquadioxalatochromate(III) anions, 2-amino-5-chloropyridinium cations and uncoordinated water molecules are linked into a three-dimensional supramolecular array by O—H...O and N—H...O hydrogen-bonding interactions. One of the two independent lattice water molecules is situated on a twofold rotation axis.

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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