DNMR, DFT and preparative study on the conformation of (Z)-4,5,6,7-tetrahydropyrazolo[1,5-e]benzo[g][1,5]diazonin-8-ones and (Z)-4,5-dihydropyrazolo[1,5-d]benzo[f][1,4]diazocin-7(6H)-ones

Structural, biological and pharmaceutical importance of antibiotic agent chloramphenicol

The vibrational, magnetic resonance and electronic spectral techniques are used to evaluate structural activity associated physico-chemical properties. The biological affinity and drug importance was validated by calculating biological parameters using HyperChem. Mulliken charge assignment for restoring chemical potential for generating drug potential in the molecular site was mapped and analyzed. The vibrational spectral pattern was estimated by identifying active and inactive bands and hindrance of vibrational activity of Acetamide group was monitored and thereby drug malfunction was tested. The chemical reaction pathway around the core carbons of chain and ring was keenly noted and the cause of chemical potential for the inducement of drug mechanism was reported. The stimulation of chemical mechanism for antibiotic activity was addressed by suitable evidence and further improvement for enhancing activity was made. The electronic HOMO and LUMO interaction over different molecular entities are discussed to expose accompany of drug mechanical transitions. The CT complex was recognized to be C=N and C=C bonds and operating drug mechanism was monitored. The unwanted drug property induced by perplexes of charge depletion on α-hydroxyl group was assessed from MEP map. The hyperactive polarization energy of 266.18 X10-33 esu and 327 X10-33 esu of present compound is causing biological activity in good order. The uncontrolled breathing region of Acetamide group was clarified in VCD profile and this is main cause to produce toxicity in drug process.

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.

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.

Infrared and Raman spectroscopic analyses and theoretical computation of 4-butyl-1-(4-hydroxyphenyl)-2-phenyl-3,5-pyrazolidinedione

Infrared and Raman spectroscopic analyses were carried out on 4-butyl-1-(4-hydroxyphenyl)-2-phenyl-3,5-pyrazolidinedione. The interpretation of the spectra was aided by DFT calculation of the molecule. The vibrational wavenumbers were examined theoretically using the Gaussian03 set of quantum chemistry codes and the normal modes were assigned by potential energy distribution calculations. A computation of the first hyperpolarizability of the compound indicates that the compound may be a good candidate as a NLO material. Optimized geometrical parameters are in agreement with the reported XRD results. The RMS error of the observed Raman bands and IR bands are found to be 35.09 and 39.57 for HF method and 14.31 and 17.17 for DFT method. The predicted infrared intensities and Raman activities are reported.