Determination of binding parameters of 2-(Ferrocenylmethylamino) Benzonitrile and 3-(Ferrocenylmethylamino)Benzonitrile WITH 1,1-Diphenyl-2-Picrylhydrazyl free radical

Abstract

Spectrophotometric technics based assay were developed for the determination of binding parameters like  binding constant and binding free energy of two potential antioxidants ferrocene derivatives:  2-(ferrocenylmethylamino)benzonitrile (2FMAB), 3-(ferrocenylmethylamino) benzonitrile (3FMAB), and a  standard ascorbic acid (AA) with 1,1-diphenyl-2- picrylhydrazyl radicals (DPPH). Obtained resultants indicated  that the adduct 3FMBA-DPPH shows hig est binding constant and highest binding free energy (2.28×10-5 M^-1) and (-30.59 KJmol^-1) respectively. Binding free energy of 3FMAB-DPPH is almost twice  greater than that of the adducts 2FMAB-DPPH (-14.47 KJmol^-1) and also is greater than the adduct formed between the standard antioxidant ascorbic acid and 1,1-diphenyl-2-picrylhydrazyl radicals (AA-DPPH) (-19.29 KJmol^-1).

Key word : ferrocene derivatives, DPPH, binding parameters, binding free energy, binding constant.