Electron Transfer Reaction of Semicarbazide and Tetrakis (2, 2’- Bipyridine)-µ- Oxodiiron (III) Complex in Aqueous Acidic Media

Abstract

The objective of this paper is to evaluate the physicochemical properties of electron transfer reaction of semicarbazide and tetrakis (2, 2’-bipyridine)-μ-oxodiiron (III) complex [Fe₂O⁴⁺] in aqueous acidic media at [H⁺] = 0.001mol dm^-3, µ = 0.3 mol dm^-3(NaCl), T = 27 ± 0.5, at  λ_max = 520 nm by spectrophotometric method. In the course of the reaction a mole of semicarbazide was consumed by a mole of [Fe₂O⁴⁺]. The order of reaction is unity dependent on [Fe₂O⁴⁺] and zero order dependent on semicabazide and is not H⁺  and µ dependent. Addition of cations and anions did not affect the reaction. There was no intermediate formation when a partially reacted reaction mixture and the solution of oxidant were respectively scanned within a wavelength of 400 -700nm. Absence of spectroscopic evidence of intermediate complex formation suggests that the reaction proceeds by the outer-sphere mechanistic pathway with ion pair character.