Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

An N-Substituted 1H-indole derivative having an empirical formula C16H13NO3S was synthesized by the <a href="https://www.sciencedirect.com/topics/chemistry/condensation">condensation</a> of 2-Methyl-1H-Indole-3-carbaldehyde and benzene <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/sulfonyl">sulfonyl</a> chloride in presence of a <a href="https://www.sciencedirect.com/topics/chemistry/phase-transfer-catalyst">phase transfer catalyst</a> of type <a href="https://www.sciencedirect.com/topics/chemistry/quaternary-ammonium-salt">quaternary ammonium salt</a> in basic conditions. Then the compound was characterized by using FT-IR, <a href="https://www.sciencedirect.com/topics/chemistry/ultraviolet-spectrum">UV–Visible</a> and NMR spectroscopic methods. Thus the obtained experimental results were effectively compared with DFT studies in arriving the structural characteristics of the title compound. From vibrational analysis, it was observed that carbonyl frequency is somewhat lower than a typical aldehydic stretching frequency and it could be possible only when the <a href="https://www.sciencedirect.com/topics/chemistry/formyl-group">formyl group</a> is coplanar with the ring and subsequent resonance conjugation reduces its force constant. Similarly, the <a href="https://www.sciencedirect.com/topics/chemistry/absorptivity">optical absorption</a> behavior of a typical <a href="https://www.sciencedirect.com/topics/chemistry/indole">indole</a> ring suffered from a bathochromic shift due to the presence of ring substituents. Finally, the molecular drug docking studies of the title compound were performed using <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/autodock">AutoDock</a> 4.2 tools to ascertain its binding mode, efficiency and the nature of chemical interactions with the target proteins and it has been predicted theoretically that the binding efficiency of the ligand on the target receptor surface was found to be better in the case of <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/gram-positive-bacterium">Gram positive bacteria</a> S. Aureus than the Gram negative N. Meningitidis.

VIT Unitversity

Department of Physics

School of Advanced Sciences

Vellore Campus

Journal of Molecular Structure

Synthesis, spectroscopic, computational and drug docking studies of 1-(benzenesulfonyl)-2-methyl-1H-indole-3-carbaldehyde

World University root node

Vibrational analysis, NBO analysis, NMR, UV–VIS, hyperpolarizability analysis of Trimethadione by density functional theory

Fourier transform infrared (FTIR) and FT-Raman spectra have been recorded and extensive spectroscopic investigations have been carried out on Sulfamethoxazole (SMX). The structural and spectroscopic data of the molecule in the ground state were calculated by using density functional method (DFT) using 6-31G(d,p) basis set. The vibrational frequencies were calculated and scaled values were compared with experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies are found to be in good agreement. (13)C and (1)H NMR chemical shifts results were given and are in agreement with the corresponding experimental values. The theoretically constructed FT-IR and FT-Raman spectra exactly coincide with experimental one. Besides, NBO, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis were investigated using theoretical calculations.

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

Molecular structure, vibrational spectra, NMR and UV spectral analysis of sulfamethoxazole

In this work, the FT-Raman and FT-Infrared spectra of 3-chloro-6-methoxypyridazine sample were measured to elucidate the spectroscopic properties of title molecule in the spectral range of 3500-50 cm(-1) and 4000-400 cm(-1), respectively. The molecular geometry and vibrational frequencies of 3-chloro-6-methoxypyridazine in the ground state were calculated using the DFT/B3LYP/6-31G(d),6-311G(d,p) level. The recorded FT-IR and FT-Raman spectral measurements favor the calculated structural parameters which are further supported by spectral simulation. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The UV-Visible absorption spectrum of the compound that dissolved in methanol was recorded in the range of 800-200 nm. The formation of hydrogen bond and the most possible interaction are explained using natural bond orbital (NBO) analysis. The isotropic chemical shift computed by (13)C and (1)H NMR analysis also shows good agreement with experimental observations. In addition, the molecular electrostatic potential (MEP) and frontier molecular orbitals (FMOs) analysis of the title compound were investigated using theoretical calculations.

Structural, vibrational, electronic and NMR spectral analysis of 3-chloro-6-methoxypyridazine by DFT calculations

Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectra of 3,4-dihydroxy-l-phenylalanine (3,4-DPA) in solid phase were recorded and analysed in this research. Along with this, the IR spectra in CHCl3 and the use of acetone as solvents of 3,4-DPA were also recorded. The equilibrium geometry, bonding features and harmonic vibrational frequencies were investigated with the help of density functional theory (DFT) method. The 1H and 13C nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge including atomic orbital method and compared with experimental results. Stability of the molecule arising from hyperconjugative interactions and charge delocalisation was analysed using natural bond orbital analysis. The results show that charge in electron density (E D) in the σ* and π* antibonding orbitals and second-order delocalisation energies E(2) confirms the occurrence of intramolecular charge transfer within the molecule. UV–vis spectrum of the compound was recorded and the electronic properties, such as HOMO and LUMO energies, were analysed using the time-dependent (TD)-DFT approach. Finally, the calculation results were applied to simulate infrared and Raman spectra of the title compound, which showed good agreement with the observed spectra.

Molecular Simulation

Molecular structure and spectroscopic (FT-IR, FT-Raman,13C,1H NMR and UV) studies of 3,4-dihydroxy-l-phenylalanine using density functional theory

The Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectra of antiepileptic drug Ethosuximide (ETX) have been recorded and analyzed. In addition, the IR spectra in CCl(4) at various concentrations of ETX are also recorded. The equilibrium geometry, bonding features and harmonic vibrational frequencies have been investigated with the help of Density Functional Theory (DFT) method. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the Gauge Including Atomic Orbital (GIAO) method. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in the σ* and π* antibonding orbitals and second order delocalization energies E(2) confirms the occurrence of intramolecular charge transfer (ICT) within the molecule. UV-vis spectrum of the compound was recorded and the electronic properties, such as HOMO and LUMO energies, were performed by Time-Dependent Density Functional Theory (TD-DFT) approach. Finally the calculation results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with observed spectra.