X-Ray Structures and Spectroscopic Properties of Chiral Thiosemicarbazides as Studied by Computational Calculations

Abstract

In the present work, (+)-(R)-1-[2-(benzenesulfonamido)-3-phenylpropanoyl]-4-[(4-methoxy)phenyl]thiose micarbazide (1a) and (-)-(S)-1-[2-(benzenesulfonamido)-3-phenylpropanoyl]-4-[(4-methoxy)phenyl] thiosemicarbazide (1b) were synthesized starting with D-phenylalanine methyl ester and L-phenylalanine ethyl ester as a source of chirality. The single crystal structures were characterized by XRD, FTIR and H-1 and C-13 NMR spectroscopy. Density functional theory (DFT) calculations (B3LYP/6-311G(d,p) were carried out to obtain the ground state optimized geometry, the IR and the NMR spectra of the molecule. Electronic properties (HOMO&LUMO) were calculated using the Time Dependant-DFT/B3LYP/6-311G(d,p) method. Furthermore, NBO, MEP, and Fukui function analyses have been used for the quantitative determination of the chemical activities at various sites of the molecule. [GRAPHICS] .