Experimental and theoretical study of S-benzyl beta-N-(-2-methyl-3-phenylallylidene)dithiocarbazate as anti-bacterial agent

摘要

The NS based S-benzyl beta-(N-2-methyl-3-phenylallylidene)dithiocarbazate (L) Schiff base was synthesized by 1:1 condensation method between S-benzyl dithiocarbazate and alpha-methyl-trans-cinnamaldehyde. The structure of the compound was elucidated by FT-IR, Mass, C-13-NMR, Raman, H-1-NMR, and UV-Vis both by spectroscopic and computational techniques. Its anti-bacterial activity is assayed against two commonly infection causing bacterial strains, namely gram-positive Staphylococcus aureus and gram-negative Escherichia coli. The results showed appreciable biological activity, and the activity increased with increase in concentration. Thermal stability of the ligand was carried by TGA up to 800 degrees C, and decomposes fully to give gaseous products. Theoretical investigation of (L) has been accomplished using the DFT-B3LYP quantum chemical method in combination with B3LYP exchange correlation functional. VEDA-4 (vibrational energy distribution analysis) software was employed for theoretical FT-IR spectrum analysis which yielded 114 fundamental vibrational modes along with a potential energy distribution percentage showing non-linearity of (L). Theoretically calculated parameters like UV-VIS, FT-IR, H-1-NMR, C-13-NMR, Raman, HOMO-LUMO energy gap and electrostatic potential were in conformity with calculated results.