Conformational stability, spectroscopic and computational studies, HOMO-LUMO, NBO, ESP analysis, thermodynamic parameters of natural bioactive compound with anticancer potential of 2-(hydroxymethyl)anthraquinone.

Natural product drugs play a dominant role in pharmaceutical care. Nature is an attractive source of new therapeutic candidate compounds as a tremendous chemical diversity is found in millions of species of plants, animals, marine organism and micro-organism. A antifungal activity against important opportunist micro-organism and against those involved in superficial mycosis, all from nosocomial origin.

Spectroscopic investigation, natural bond orbital analysis, HOMO-LUMO and thermodynamic functions of 2-tert-butyl-5-methyl anisole using DFT (B3LYP) calculations.

The optimized molecular structure and corresponding vibrational assignments of 2-tert-butyl-5-methyl anisole (TBMA) have been investigated using density functional theory (DFT)/B3LYP with 6-31G(d,p) and 6-311++G(d,p) basis sets investigation of the relative orientation of the methoxy group has shown two conformers (O-cis) and (O-trans) exist. The vibrational analysis of the stable conformer of the title compound is performed by means of infrared absorption and Raman spectroscopy in combination with theoretical simultaneously. The natural bond orbital (NBO) analysis is useful to understand the intra-molecular hyper conjugative interaction lone pair and π(∗)(C-C), σ(∗)(C-H) bond orbital.

Conformational stability, vibrational (FT-IR and FT-Raman) spectra and computational analysis of m-trifluoromethyl benzoic acid.

In this work, the vibrational characteristics of m-trifluoromethyl benzoic acid have been investigated and both the experimental and theoretical vibrational data indicate the presence of functional groups in the title molecule. The density functional theoretical (DFT) computations were performed at the B3LYP/6-31G (d, p), LSDA/6-31G (d, p), MP2/6-31G (d, p) levels to derive the optimized geometry, vibrational wavenumbers. Furthermore, the molecular orbital calculations such as natural bond orbitals (NBO), HOMO-LUMO energy gap and Mapped molecular electrostatic potential (MEP) surfaces, The Mulliken charges, the first-order hyperpolarizability were also performed with the same level of DFT.

Conformational stability, vibrational and NMR analysis, chemical potential and thermodynamical parameter of 3-tert-butyl-4-hydroxyanisole.

The FT-IR and FT-Raman spectra of 3-tert-butyl-4-hydroxyanisole (TBHA) molecule have been recorded in the region 4000-400 cm(-1) and 3500-100 cm(-1), respectively. Optimized geometrical structure, harmonic vibrational frequencies has been computed by B3LYP level using 6-31G (d,p) and 6-311+G (d,p) basis sets. The observed FT-IR and FT-Raman vibrational frequencies are analyzed and compared with theoretically predicted vibrational frequencies.

Conformational stability, spectroscopic (FT-IR & FT-Raman), HOMO-LUMO, NBO and thermodynamic function of 4-(trifloromethoxy) phenol.

FT-IR and FT-Raman spectra of 4-(trifloromethoxy) phenol (4TFMP) have been recorded in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. The total energy calculations of 4TFMP were tried for the possible conformers. The molecular structure, geometry optimization, vibrational frequencies were obtained by the DFT level of theory (B3LYP) with the standard basis sets 6-31+G(d) and 6-311++G(d,p).