Isaac H. Joe

Spectroscopic investigation and hydrogen-bonding analysis of triazinones.

AbstractNIR FT-Raman, FTIR and UV-vis spectra of the herbicide metamitron were recorded and analyzed. The aromaticities, equilibrium geometries, bonding features, electrostatic potentials, and harmonic vibrational wavenumbers of the monomers and dimers of triazinone derivatives were also investigated with the aid of BLYP/6-311 G(df, p) density functional theory. Features in the vibrational spectra were assigned with the aid of the VEDA.4 program. The calculated results were a good match to the experimental data obtained from FTIR, Raman, and electronic absorption spectra. Mulliken population analysis was performed on the atomic charges and the HOMO–LUMO energies were also calculated. NBO analysis highlighted the intra- and intermolecular N–H…O and C–H…O hydrogen bonds in the crystal structures of the triazinones. The solvent effect was calculated using time-dependent density functional theory in combination with the polarizable continuum model. FigureFT-Raman and IR, UV-Vis spectra were used to investigate bioactivity of triazinone derivatives. The vibrational analysis expounds the charge transfer interaction of the molecule. The solvent effects have been calculated using the time-dependent density functional theory in combination with the polarized continuum model. The intra and intermolecular N-H…O and C-H…O hydrogen bonds in the crystal structures of triazinone herbicides are also investigated.

Spectroscopic Investigations, DFT Calculations, and Molecular Docking Studies of the Anticonvulsant (2E)-2-[3-(1H-Imidazol-1-yl)-1-phenylpropylidene]-N-(4-methylphenyl)hydrazinecarboxamide

Drug discovery for the management of neurological disorders is a challenging arena in medicinal chemistry. Vibrational spectral studies of (2E)-2-[3-(1H-imidazol-1-yl)-1-phenylpropylidene]-N-(4-methylphenyl)hydrazinecarboxamide ((2E)-IPPMP) have been recorded and analyzed to identify the functional groups and intermolecular/intramolecular interactions of the title molecule. The blue shift of the C-H stretching wavenumber reveals the presence of improper C-H⋯O hydrogen bonding. The equilibrium geometry, harmonic vibrational wavenumbers, Frontier orbital energy, and natural bond orbital analyses have been carried out using density functional theory with a B3LYP/6-311

Triphenylamine Derived 3-Acetyl and 3-Benzothiazolyl Bis and Tris Coumarins: Synthesis, Photophysical and DFT Assisted Hyperpolarizability Study

Triphenylamine derived bis- and tris-branched donor-pi-acceptor coumarins with acetyl and benzothiazolyl acceptors are studied for their linear and nonlinear optical properties that originate from their photophysical and molecular structure. Plots of solvent polarities versus the Stokes shift, frontier molecular orbital analysis and Generalised Mulliken Hush analysis have established their strong charge transfer character supported by the strong emission solvatochromism of these chromophores. On the basis of excited state intramolecular charge transfer, the first-, second- and third-order polarizability of these dyes are determined by a solvatochromic method and supported by density functional theory calculations using CAM-B3LYP/6-31g(d). Compared to the acetyl group, the benzothiazolyl group is a strong acceptor, and its corresponding derivatives show enhanced absorption, emission maxima and non-linear optical response. Bond length alternation and bond order alternation analysis reveals that these chromophores approach the cyanine-like framework which is responsible for maximum perturbation to produce high nonlinear optical response. Third order nonlinear susceptibility for dyes 1 and 2 is determined by Z-scan measurement. All of these methods are used to determine the nonlinear optical properties, and thermogravimetric analysis suggests that these chromophores are thermally robust and efficient nonlinear optical materials.

Bis(glycylglycinium) oxalate at 100 K

The structure of the title compound, 2C(4)H(9)N(2)O(3)(+).C(2)O(4)(2-), which has been determined by X-ray diffraction, contains discrete glycylglycine (HGly-Gly)(+) cations in general positions and oxalate anions which lie across centres of inversion. Although the geometry of the (HGly-Gly)(+) cation is not significantly different compared with other structures containing this residue, a few changes in conformation are observed which indicate the presence of molecular interactions. The molecular network in the crystal consists of one nearly linear O-H...O, five N-H...O and two weak C-H.O hydrogen bonds.

Vibrational and electronic profiles, molecular docking and biological prediction of 5-methoxy-1-[(5-methoxy- 1H-indol-2-yl)methyl]-1H-indole: Experimental and theoretical investigations

Indole derivatives represent an important class of privileged structures. Spectroscopic (Fourier transform infrared (FT-IR), FT-Raman, 1H and 13C nuclear magnetic resonance (NMR)) investigations of the indole-bearing title compound, namely 5-methoxy-1-[(5-methoxy-1H-indol-2-yl)methyl]-1H-indole (MMIMI) have been carried out. The corresponding data of the MMIMI molecule were analyzed to understand its optimized geometry, and inter/intra-molecular interactions. The equilibrium geometry, harmonic vibrational wavenumbers, Frontier orbital energy, and natural bond orbital (NBO) analyses have been performed with the help of density functional theory (DFT) with B3LYP/6-311++G(d,p) level of theory. The vibrational modes have been unequivocally assigned using potential energy distribution analysis. The theoretically predicted wavenumbers have good agreement with the experimental values. NBO has confirmed the intra-molecular charge transfer interactions. HOMO–LUMO analysis was carried out to explore charge delocali...