scholarly journals DFT study and NBO analysis of solvation/substituent effects of 3-phenylbenzo[d]thiazole-2(3H)-imine derivatives

2020 ◽  
Vol 85 (11) ◽  
pp. 1445-1462
Author(s):  
Marzieh Miar ◽  
Abolfazl Shiroudi ◽  
Khalil Pourshamsian ◽  
Ahmad Oliaey ◽  
Farhad Hatamjafari
Keyword(s):  
Charge Transfer ◽  
Relative Stability ◽  
Energy Gap ◽  
Substituent Effects ◽  
Nbo Analysis ◽  
Frontier Molecular Orbital ◽  
Thiazole Ring ◽  
Chemical Thermodynamics ◽  
Lumo Energy ◽  
Homo Lumo

In this work, to determine natural bond orbital (NBO) analysis, solvation and substituent effects for electron-releasing substituents (CH3, OH) and electron-withdrawing derivatives (Cl, NO2, CF3) in para positions on the molecular structure of the synthesized 3-phenylbenzo[d]thiazole-2(3H)-imine derivatives 1?6 (H (1), CH3 (2), Cl (3), OH (4), CF3 (5), NO2 (6)) in the selected solvents (acetone, toluene, and ethanol) and gas-phase employing polarizable continuum method (PCM) model were studied at the M06-2x/6- -311++G(d,p) level of theory. The relative stability of the studied compounds was affected by the possibility of intramolecular interactions between substituents and the electron donor/acceptor centers of the thiazole ring. Furthermore, atomic charges electron density, chemical thermodynamics, energetic properties, dipole moments, and the nucleus-independent chemical shifts (NICS) of the studied compounds and their relative stability are considered. The dipole moment values and the HOMO?LUMO energy gap reveal the different charge transfer possibilities within the considered molecules. Frontier molecular orbital (FMO) analysis revealed that compound 6 has very small HOMO-LUMO energy gaps in the considered phases, and thus is kinetically less stable. The obtained HOMO-LUMO energy gap corresponds to intramolecular hyperconjugative interactions ?? ?*. Finally, NBO analysis is carried out to demonstrate the charge transfer between localized bonds and lone pairs.

scholarly journals Trans influence and substituent effects on the HOMO-LUMO energy gap and Stokes shift in Ru mono-diimine derivatives

2019 ◽  
Vol 1195 ◽  
pp. 620-631 ◽  
Author(s):  
Sanaa AlAbbad ◽  
Tova Sardot ◽  
Oliko Lekashvili ◽  
Daniel Decato ◽  
Francesco Lelj ◽  
...  
Keyword(s):  
Energy Gap ◽  
Stokes Shift ◽  
Substituent Effects ◽  
Lumo Energy ◽  
Trans Influence ◽  
Homo Lumo

scholarly journals Crystal Structure, Spectral investigations, DFT and Antimicrobial activity of Brucinium Benzilate (BBA)

2021 ◽  
Author(s):  
Karnan Chandran ◽  
Nagaraja Karachalacherevu Seetharamiah ◽  
Manivannan Sambanthan ◽  
Manikandan Anandhan ◽  
Ragavendran Venkatesan
Keyword(s):  
Molecular Electrostatic Potential ◽  
Energy Gap ◽  
Intramolecular Hydrogen Bonding ◽  
Frontier Molecular Orbital ◽  
Lumo Energy ◽  
Ammonium N ◽  
Intramolecular Hydrogen ◽  
Homo Lumo ◽  
Binding Plasma Protein ◽  
Tertiary Nitrogen

Abstract The unreported Brucinium Benzilate (BBA) crystal and hirshfeld surface analysis indicated the influence of intramolecular hydrogen bonding network. The protonation of tertiary nitrogen occurs as it is most basic. The protonated N-H+ proton was observed at 7.08 ppm and the benzilate carbon COO- at 178.41 ppm. Molecular electrostatic potential (MEP) studies indicated the electron-rich and electron-deficient sites in the molecule for understanding BBA interaction with an enzyme. Frontier molecular orbital (FMO) studies indicated that it is thermodynamically stable and HOMO-LUMO energy gap was found to be 4.454 eV. The highest interaction as the energy (322.86 kcal/mol) between tertiary ammonium N(LP) and H+. The compound showed the inhibition of Bacillus cereus and Salmonella typhimurium bacteria. ADMET properties indicated that BBA has drug characteristics in binding plasma protein.

scholarly journals Theoretical investigations on the HOMO–LUMO gap and global reactivity descriptor studies, natural bond orbital, and nucleus-independent chemical shifts analyses of 3-phenylbenzo[d]thiazole-2(3H)-imine and its para-substituted derivatives: Solvent and substituent effects

2020 ◽  
pp. 174751982093209
Author(s):  
Marzieh Miar ◽  
Abolfazl Shiroudi ◽  
Khalil Pourshamsian ◽  
Ahmad Reza Oliaey ◽  
Farhad Hatamjafari
Keyword(s):  
Charge Transfer ◽  
Molecular Orbital ◽  
Relative Stability ◽  
Natural Bond Orbital ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Natural Bond Orbital Analysis ◽  
Orbital Energy ◽  
Thiazole Ring ◽  
Orbital Analysis

Natural bond orbital analysis, salvation, and substituent effects of electron-releasing (–CH3, –OH) and electron-withdrawing (–Cl, –NO2, –CF3) groups at para positions on the molecular structure of synthesized 3-phenylbenzo[ d]thiazole-2(3 H)-imine and its derivatives in selected solvents (acetone, toluene, and ethanol) and in the gas phase by employing the polarizable continuum method model are studied using the M06-2x method and 6-311++G(d,p) basis set. The relative stability of the studied compounds is influenced by the possibility of intramolecular interactions between substituents and the electron donor–acceptor centers of the thiazole ring. Furthermore, atomic charges, electron density, chemical thermodynamics, energetic properties, dipole moments, and nucleus-independent chemical shifts of the studied compounds and their relative stability are considered. The dipole moment values and the highest occupied molecular orbital–lowest unoccupied molecular orbital energy gaps reveal different charge-transfer possibilities within the considered molecules. Finally, natural bond orbital analysis is carried out to picture the charge transfer between the localized bonds and lone pairs.

scholarly journals Adsorption of 2,4,6-trichlorophenol on kaolinite: DFT calculations

2017 ◽  
Vol 6 (3) ◽  
pp. 141-152 ◽  
Author(s):  
Sara Ghezali ◽  
Amina Mahdad-Benzerdjeb
Keyword(s):  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Energy Gap ◽  
Organic Pollutant ◽  
Nbo Analysis ◽  
Lumo Energy ◽  
Preferential Adsorption ◽  
Donor Acceptor ◽  
Kaolinite Surface ◽  
Homo Lumo

The aim of this work is to explore the adsorption process of an organic pollutant the 2,4,6-trichlorophenol on the clay mineral (kaolinite) surface in order to identify the sites of adsorption as well as conformations corresponding to the lowest energies. Ab-initio calculations have been used to investigate the adsorption process using a representative cluster model. According to the results obtained on the various studied models, the orientation of TCP on the surfaces clay affect the parameters such as : HOMO-LUMO energy gap, the enthalpy change (ΔH), the thermal Gibbs free energy (ΔG) and entropy contribution (ΔS). The results point out a preferential adsorption of TCP on the octahedral surface and the NBO analysis indicates that the electron donor-acceptor complex was the dominant adsorption mechanism.

Theoretical investigation on vibrational spectroscopic and nonlinear optical activity of 1-(4-chloro phenyl)-3-(4-dimethylamino phenyl) prop-2-en-1-one

2017 ◽  
Vol 95 (4) ◽  
pp. 353-360
Author(s):  
Xiao-Hong Li ◽  
Hong-Ling Cui ◽  
Rui-Zhou Zhang
Keyword(s):  
Density Functional ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
Density Functional Theory Method ◽  
Nbo Analysis ◽  
Frontier Molecular Orbital ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Electron Donation ◽  
Homo Lumo

The density functional theory method was used to calculate the vibrational spectrum, geometrical structure of 1-(4-chloro phenyl)-3-(4-dimethylamino phenyl) prop-2-en-1-one in the ground state. The analysis of natural bond orbital (NBO) was also performed. The infrared spectrum was obtained and interpreted by means of potential energies distributions. NBO analysis shows that electron donation from LP(1)N atom to the anti-bonding acceptor σ*(C6–C12) of the phenyl ring results in the stabilization of 43.9 kJ/mol. The predicted NLO properties show that the βtot of the title compound is larger than that of urea and is a good candidate as a nonlinear optical material. In addition, the frontier molecular orbital is also investigated. The high βtot value and the low HOMO–LUMO energy gap assert the suitability of the grown crystal for NLO applications.

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.

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.

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.

ab initio MO Optimization of Molecular Structures of Fluoro- and Chloro-Substituted Dibenzo-p-dioxines and the Effect of Halogen Substitution at the 2,3,7,8-Positions on Metabolic Attack

1997 ◽  
Vol 52 (11) ◽  
pp. 1418-1431 ◽  
Author(s):  
Roland Weber ◽  
Till Kühn ◽  
Hanspaul Hagenmaier ◽  
Günter Häfelinger
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Energy Gap ◽  
Substituent Effects ◽  
Molecular Structures ◽  
X Ray ◽  
Degree Pattern ◽  
Chlorine Substituent ◽  
Homo Lumo ◽  
Good Agreement

Full ab initio optimizations were performed on the molecular structures of 24 fluorinated and chlorinated dibenzodioxines (PFDD/PCDD ) and dibenzofurans (PFDF/PCDF). Reasonable agreement was found by comparing the geometries of four calculated structures with known X-ray data from the literature. For the fluorine substituent, calculated electron densities (Mulliken total charges and π-electron charges) clearly demonstrate the opposite influence of the inductive (I) and mesomeric (M) effect. The changes in π-densities at carbons in ortho-, meta- and para-position are constant for each fluorine substituent (independent of degree, pattern, and position of substitution). It is thus possible to calculate the π-densities of the substituted dioxines by increments starting from dibenzodioxine. π-Charges from quantum mechanical calculations and the increment system show good agreement even for OctaFDD (O8FDD ), where eight substituent effects are acting additively. Compared with fluorine, the chlorine substituent exercises a smaller -I-effect and a clearly weaker +M-effect. The HOMO coefficients of the unsubstituted dibenzodioxine and dibenzofuran, extracted from ab initio calculations, yield a good explanation for the observed regioselective metabolic attack at the 2,3,7,8-positions. The squares of the HOMO-coefficients of the 2,3,7,8-positions in dibenzodioxine (DD ) are about ten times greater than those of the 1,4,6,9-positions. These HOMO coefficients are practically unaffected by halide substitution. But halogen substitution reduces strongly the electron density at the halogen-bound carbon, which, however, is a necessary prerequisite for the electrophilic oxygen transfer during metabolism. One would therefore expect halogen substitution of dibenzodioxine and dibenzofuran (DF) at the 2,3,7,8-position to hinder metabolism, as is indeed found. This provides a plausible explanation for the highly selective tissue retention of 2,3,7,8-substituted PCDDs and PCDFs. Our ab initio calculations of five tetra CDDs (T4CDDs) confirm the postulate of Kobayashi et al. [1 ] who, using semiempirical calculations, found a correlation between the toxicity of a dioxine congener and its absolute molecular hardness. The 2,3,7,8-T4CDD also exhibits the smallest absolute hardness (derived from the HOMO-LUMO energy gap) in our calculations.

SOLVENT EFFECTS ON THE ELECTRONIC STRUCTURE AND NON-LINEAR OPTICAL PROPERTIES OF PYRENE AND SOME OF ITS DERIVATIVES BASED ON DENSITY FUNCTIONAL THEORY

2021 ◽  
Vol 4 (4) ◽  
pp. 236-251
Author(s):  
A. S. Gidado ◽  
L. S. Taura ◽  
A. Musa
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Energy Gap ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Lumo Energy ◽  
Functional Theory ◽  
Organic Optoelectronic ◽  
Homo Lumo

Pyrene (C16H10) is an organic semiconductor which has wide applications in the field of organic electronics suitable for the development of organic light emitting diodes (OLED) and organic photovoltaic cells (OPV). In this work, Density Functional Theory (DFT) using Becke’s three and Lee Yang Parr (B3LYP) functional with basis set 6-311++G(d, p) implemented in Gaussian 03 package was  used to compute total energy, bond parameters, HOMO-LUMO energy gap, electron affinity, ionization potential, chemical reactivity descriptors, dipole moment, isotropic polarizability (α), anisotropy of polarizability ( Δ∝) total first order hyper-polarizability () and second order hyperpolarizability (). The molecules used are pyrene, 1-chloropyrene and 4-chloropyrene  in gas phase and in five different solvents: benzene, chloroform, acetone, DMSO and water. The results obtained show that solvents and chlorination actually influenced the properties of the molecules. The isolated pyrene in acetone has the largest value of HOMO-LUMO energy gap of and is a bit closer to a previously reported experimental value of  and hence is the most stable. Thus, the pyrene molecule has more kinetic stability and can be described as low reactive molecule. The calculated dipole moments are in the order of 4-chloropyrene (1.7645 D) < 1-chloropyrene (1.9663 D) in gas phase. The anisotropy of polarizability ( for pyrene and its derivatives were found to increase with increasing polarity of the solvents.  In a nutshell, the molecules will be promising for organic optoelectronic devices based on their computed properties as reported by this work.

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