scholarly journals Molecular Orbital Study of Flouroaryl Substituted Amino-Borane Dimers: Geometry, Energetics and Reactivity

2019 ◽  
Vol 31 (8) ◽  
pp. 1785-1790
Author(s):  
Shikha Gulati ◽  
Divya Lamba ◽  
H.C. Tandon
Keyword(s):  
Electronic Properties ◽  
Molecular Orbital ◽  
Chemical Reactivity ◽  
Parametric Method ◽  
Geometrical Parameters ◽  
Electrophilicity Index ◽  
Lumo Energy ◽  
Molecular Orbital Study ◽  
Homo Lumo ◽  
Good Agreement

The electronic properties in terms of HOMO-LUMO energy, electronegativity, hardness and electrophilicity index have been calculated and discussed in the framework of Unrestricted Hartee-Fock (UHF), semi-emperical parametric method (PM3) for six fluoro-substituted aminoborane dimers, viz. [Me2B-μ-N(H)ArF]2 (Ar: 4-C6H4F (1), 2-C6H5F (2); 3,5-C6H3F2 (3); 2,3,4,5-C6HF4 (4); 2,3,5,6-C6HF4 (5) and C6F5 (6)). The calculated parameters mentioned above have been compared with the available experimental and other theoretical estimates. The results are in excellent agreement with the reported estimates. The geometrical parameters calculated are also in good agreement with available experimental and theoretical values. The chemical reactivity is also discussed in terms of electrophilicity index (ω) values.

scholarly journals Electronic Structure of Two New Bis-Schiff Base Ligands using DFT Method

2021 ◽  
pp. 10-15
Author(s):  
Elham Abdalrahem Bin Selim ◽  
Mohammed Hadi Al–Douh ◽  
Hassan Hadi Abdullah ◽  
Dahab Salim Al–Nohey
Keyword(s):  
Experimental Data ◽  
Biological Activity ◽  
Metal Ion ◽  
Energy Levels ◽  
Dft Method ◽  
Ftir Spectra ◽  
Schiff Base Ligands ◽  
Lumo Energy ◽  
Homo Lumo ◽  
Good Agreement

Two bis-Schiff Bases 1 and 2 are ligands that can coordinate with manganese metal to form stable complexes and have biological activity. Thermodynamic parameters, HOMO-LUMO energy levels and FTIR spectra of two ligands have been computed using B3LYP/6-311++G(d,p) functional of the DFT calculations. Both ligands are favored thermodynamically, and the ligand 1 has been shown to be more stable than ligand 2. The Polarizability values of two ligands have been investigated. The results refer that ligand 2 interacts earlier than ligand 1 to the metal ion. The FTIR spectra of two ligands have been evaluated. All results show the good agreement between the theoretical and experimental data.

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.

scholarly journals HOMO–LUMO energy gap control in platinum(ii) biphenyl complexes containing 2,2′-bipyridine ligands

2015 ◽  
Vol 44 (39) ◽  
pp. 17075-17090 ◽  
Author(s):  
D. Paul Rillema ◽  
Stanislav R. Stoyanov ◽  
Arvin J. Cruz ◽  
Huy Nguyen ◽  
Curtis Moore ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Energy Gap ◽  
Lumo Energy ◽  
Covalently Bonded ◽  
Gap Control ◽  
Homo Lumo

Electronic properties including the HOMO–LUMO energy gap in Pt(ii) complexes can be effectively controlled using electron-donating and electron-withdrawing moieties covalently bonded to the ligands.

Sulfonyl radicals, sulfinic acid, and related species: an abinitio molecular orbital study

1980 ◽  
Vol 58 (4) ◽  
pp. 331-338 ◽  
Author(s):  
Russell J. Boyd ◽  
Abha Gupta ◽  
Richard F. Langler ◽  
Stephen P. Lownie ◽  
James A. Pincock
Keyword(s):  
Molecular Orbital ◽  
Functional Group ◽  
Basis Set ◽  
Geometrical Parameters ◽  
Molecular Orbital Calculations ◽  
Sulfinic Acid ◽  
Molecular Orbital Study ◽  
Polarization Functions ◽  
Total Energies ◽  
D Orbitals

Extensive abinitio molecular orbital calculations on six sulfonyl radicals (XSO2 where X = H, CH3, NH2, OH, F, and Cl), the simplest sulfinic acid HSO2H3 and its isomeric sulfone H2SO2, the HSO2− anion of sulfinic acid, the isomeric anion SO2H−, and for completeness, the SO2H radical are presented. By use of the STO-3G* basis set, which includes d-type polarization functions on second-row atoms, all geometrical parameters are varied until the total energy is minimized, subject only to certain symmetry restrictions specified for each system. The inclusion of d orbitals on S is observed to affect the S—O bond lengths by as much as 0.45 Å. The calculations suggest that the radical site in sulfonyl radicals is significantly delocalized over the entire functional group and that the geometrical parameters of the SO2 functional group in sulfonyl radicals are nearly independent of the substituent (r(S—O) = 1.47 ± 0.01 Å, < OSO = 123 ± 2°). Estimates of the X—S bond energy in CH3SO2, NH2SO2, and OHSO2 are consistent with the chemistry of alkylsulfonyl and aminosulfonyl radicals and lead to an interesting prediction for alkoxylsulfonyl radicals. Furthermore the calculations yield lower total energies for HSO2H, HSO2−, and SO2H than for the respective isomeric forms H2SO2, SO2H−, and HSO2.

Comparative studies of excited state intramolecular proton transfer (ESIPT) and azo-hydrazone tautomerism in naphthalene-based fluorescent acid azo dyes by computational study

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Suvidha Shinde ◽  
Nagaiyan Sekar
Keyword(s):  
Molecular Orbital ◽  
Computational Study ◽  
Intramolecular Proton Transfer ◽  
Energy Band Gap ◽  
Light Fastness ◽  
Electrophilicity Index ◽  
Lumo Energy ◽  
Highest Occupied Molecular Orbital ◽  
Hardness Values ◽  
Hydrazone Form

AbstractWe found that benzothiazole is responsible for enhancing fastness properties of dyes. On comparing the total electronic energies of naphthol tautomers (−1425.16 eV) and its analogs (−2146.59 eV), we found that benzothiazolyl series is more stable than the naphthol series. Frontier Molecular Orbitals (FMOs) also show flow of charge transfer from the donor to the acceptor in benzothiazole-containing compounds, whereas it is absent in plane naphthol series. Among the benzothiazolyl isomers, the hydrazone form is found to be more stable and responsible for fluorescence possession. Highest Occupied Molecular Orbital (HOMO)–Lowest Occupied Molecular Orbital (LUMO) energy band gap also indicates the same. Electrophilicity index and hyper-hardness values of both the series were found to be positive which directly ratifies photostability and reactivity. Benzothiazolyl series was found to be more stable, hence light fastness, enhanced.

scholarly journals Xrd, Quantum Chemical, Vibrational, Thermal and Antifungal Activity Analysis on 3-Nitroanilinium Hydrogen Oxalate

2019 ◽  
Vol 9 (1S3) ◽  
pp. 319-323
Keyword(s):  
Density Functional ◽  
Density Functional Method ◽  
Functional Method ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Geometrical Parameters ◽  
Vibrational Assignments ◽  
Hartree Fock ◽  
Homo Lumo ◽  
Good Agreement

3-nitroanilinium hydrogen oxalate has been crystallized successfully by solvent evaporation method. Optimized molecular geometrical parameters and the vibrational assignments of 3NAOX has been calculated by using Hartree-Fock (HF) and density functional method (B3LYP) with 6-311++G (d, p) basis set. The computational analysis showed good agreement with the experimental data. The energy and various parameters were obtained by HOMO–LUMO plot. The apparent pharmaceutical/biological activity of the salt confirmed by lower band gap value obtain from the Frontier Molecular Orbital (FMO) analysis. Thermal properties of 3NAOX were analyzed by TGA/DTA. The grown crystals were involved in an antimicrobial activity against certain potentially threatening microbes which shows that grown crystal screened the bacteria.

scholarly journals Vibrational Spectroscopic and Computational Analysis of 5-chloro-2-hydroxy Acetophenone

2020 ◽  
Vol 8 (4S4) ◽  
pp. 254-259
Keyword(s):  
Density Functional ◽  
Computational Analysis ◽  
Energy Gap ◽  
Molecular System ◽  
Basis Sets ◽  
Geometrical Parameters ◽  
Lumo Energy ◽  
Functional Theory ◽  
Infrared Intensities ◽  
Homo Lumo

Fourier Transfer infrared and Raman spectra in the range of 4000-400 cm-1 and 3500-50 cm-1 were recorded to study the vibrational spectra of 5-chloro-2-hydroxyacetophenone (CHAP). Using density functional theory (DFT/B3LYP) with 6-31+G(d,p) and 6-311++G(d,p) basis sets the various geometrical parameters such as Raman activities, infrared intensities and optimum frequencies were calculated. The HOMO-LUMO energy gap has been computed which confirms the charge transfer of the molecular system. Mulliken’s atomic charges associated with each atom and thermodynamic parameters have also been reported with the same level of DFT.

scholarly journals Density functional study of structures, stabilities and electronic properties of AgAunλ(λ=0,±1;n=1-12){\rm{AgAu}}_n^\lambda \left( {\lambda = 0, \pm 1;n = 1 - 12} \right) clusters: comparison with pure gold clusters

2020 ◽  
Vol 38 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Prabhat Ranjan ◽  
Tanmoy Chakraborty ◽  
Ajay Kumar
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Gold Clusters ◽  
Pure Gold ◽  
Functional Study ◽  
Bimetallic Clusters ◽  
Planar Geometry ◽  
Lumo Energy ◽  
Energy Gaps ◽  
Homo Lumo

AbstractGeometrical structures, relative stabilities and electronic properties of neutral, cationic and anionic pure gold {\rm{A}}u_{n + 1}^\lambda and Ag-doped bimetallic {\rm{AgAu}}_n^\lambda \left( {\lambda = 0, \pm 1;n = 1 - 12} \right) clusters have been systematically investigated by using density functional theory methodology. The optimized structures show that planar to three-dimensional structural transition occurs at n = 5 for cationic clusters. Due to strong relativistic effect of Au clusters, the ground state configurations of neutral and anionic bimetallic clusters favor planar geometry till n = 12. Silver atoms tend to occupy the most highly coordinated position and form the maximum number of bonds with Au atoms. The computed HOMO-LUMO energy gaps, fragmentation energies and second-order difference of energies show interesting odd-even oscillation behavior. The result indicates that AgAu5, {\rm{AgAu}}_2^ + and {\rm{AgAu}}_2^ - are the most stable clusters in this molecular system. The DFT based descriptors of bimetallic clusters are also discussed and compared with pure gold clusters. The high value of correlation coefficient between HOMO-LUMO energy gaps and DFT based descriptors supports our analysis. A good agreement between experimental and theoretical data has been obtained in this study.

Sign in / Sign up

Export Citation Format

Share Document