Cholesterol thiosalicylate, a novel cholesterol conjugate its synthesis experimental studies conformational analysis chemical reactivity intermolecular interaction and first order hyperpolarizability

Abstract

In the present work 10,13-dimethyl-17-(6-methylheptan-2-yl)-tetradecahydro-1H-cyclopentaphenanthren-3-yl-2-mercaptobenzoate (2) was synthesized from Cholesterol (1), isolated as a major component from chloroform extract of Allamandaviolacea.The synthesized compound (2) has been characterized with the help of 1H, 13C, UV, FT-IR spectroscopy. The molecular geometry of synthesized compound was calculated by Density functional theory (DFT) with B3LYP functional and 631G (d,p) basis set in ground state.1H and 13C NMR chemical shifts were calculated in ground state by using Gauge-Including Atomic Orbital (GIAO) approach and these values were correlated with experimental observations. The electronic properties such as HOMO and LUMO energies were calculated using time dependentDensity Functional Theory (TD-DFT). The strength and intra molecular interactions were analyzed by AIM (Atom in molecule) approaches. Global reactivity descriptors were calculated to study the reactive sites within molecule. The vibrational wavenumbers were calculated using DFT method and assigned with the help of potential energy distribution (PED). Dipole moment, polarizability and first hyperpolarizability values have been determined to explain the nonlinear optical (NLO) property of the synthesized compounds. Molecular electrostatic potential (MEP) and conformational analysis has also been performed. The local reactivity descriptors Fukui functions (fk+, fk–), local softness's (sk+, sk–) and electrophilicity indices (ωk+, ωk–) determined the reactive sites within molecule