D. Tamilvendan

In Silico vibrational spectroscopic investigation on antioxidant active Mannich base 1-[anilino (phenyl) methyl] pyrrolidine-2,5-dione.

The antioxidant active Mannich base 1-[anilino (phenyl) methyl] pyrrolidine-2,5-dione (APMPD) have been synthesized and its FT-IR and FT-Raman vibrational spectra were recorded within the region of 4000cm(-1), 50cm(-1) respectively. The molecular geometric parameters of APMPD have been computed using HF and DFT model theories. The energies of APMPD are calculated for all the eight possible conformers using B3LYP method at 6-311++G(d,p) basis set. From the computational results, the M1 conformer was identified as the most stable conformer of APMPD. The stable conformer was compared with experimental crystal geometry, which again fortifies the results of conformer analysis. The fundamental vibrations of the molecule are assigned according to the characteristic region and the literature report. The predicted highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy gap provide vivid idea on charge transfer behavior of APMPD. The molecular electrostatic potential (MEP) and Mulliken charge analysis indicate the feasible electrophilic and nucleophilic reactive sites on APMPD. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the title compound at various temperatures are calculated in gas phase.

First principles and DFT supported investigations on vibrational spectra and electronic structure of 2-((phenylamino)methyl)isoindoline-1,3-dione--an antioxidant active Mannich base.

The 2-((phenylamino)methyl)isoindoline-1,3-dione (PID) is a synthesized Mannich base which has significant antioxidant activity and biological importance. Quantum mechanical calculations on energy, geometry and vibrational wavenumber of PID were computed using ab initio HF and density functional theory (DFT/B3LYP) methods with 6-31+G/6-311++G(d,p) basis sets. Optimized geometrical parameters obtained by HF and DFT calculations were indicatively agreement with experimental crystal geometry. The experimental FT-Raman and FT-IR spectra of PID has been recorded and analyzed by comparing with simulated spectra. The (1)H and (13)C NMR spectra of title molecule records the chemical shift resulted from shielding and deshielding effects. Natural bond orbital (NBO) analysis has been carried out to calculate various intramolecular interactions that are accountable for the stabilization of this Mannich base. The predicted HOMO-LUMO gap offers interesting information on intramolecular charge transfer and reactivity of the molecular system. Molecular electrostatic potential (MEP) imprint visualize the reactive sites in PID, which is also supported by Mulliken, ESP, Hirshfeld and NBO charges. Thermodynamic properties of PID at various temperatures have been calculated at B3LYP/6-311++G(d,p) in gas phase and the correlations between standard entropies (S), internal energy (E or U) and standard heat capacity (C) with different temperatures.

N-[Morpholino(phen-yl)meth-yl]benzamide.

The title compound, C18H20N2O2, crystallizes with two molecules in the asymmetric unit. The morpholine rings of both molecules adopt chair conformations. The crystal structure is stabilized by intermolecular N—H⋯O hydrogen bonds. One phenyl ring is disordered over two orientations in a 0.665 (5):0.335 (5) ratio.

N,N′-(Phenyl­imino­dimethyl­ene)di­prop-2-enamide hemihydrate

In the title compound, C14H17N3O2·0.5H2O, the asymmetric unit consists of an N,N′-(phenyliminodimethylene)diprop-2-enamide molecule and one half-molecule of water, with the O atom of the latter having 2 site symmetry. The supramolecular architecture is framed by the interplay of two-dimensional networks of both O—H⋯O and N—H⋯O interactions supported by C—H⋯O and edge-to-face C—H⋯π interactions.

Dicyclo­hexyl­ammonium 3-[(hy­droxy­meth­yl)carbamo­yl]propano­ate

The title compound, C12H24N+·C5H8NO4 −, contains one dicyclohexylammonium cation and one 3-[(hydroxymethyl)carbamoyl]propanoate anion in the asymmetric unit. In the crystal, the ions are linked by intermolecular N—H⋯O and O—H⋯O hydrogen bonds, forming chains propagating along [100].