A symmetric oxo-centered trinuclear chloroacetato bridged iron(III) complex: Structural, spectroscopic and electrochemical studies

An oxo-centred, carboxylate bridged trinuclear iron(III) complex [Fe-3(mu(3)-O)(O2CCH2Cl)(6)(H2O)(3)]ClO4 center dot 9H(2)O (1 center dot 9H(2)O) has been synthesized and characterized on the basis of X-ray crystallography, elemental analysis, cyclic voltammetric, UV-vis and IR spectroscopic techniques. Molecular structure has been established by X-ray diffraction analysis and reveals that the complex 1 center dot 9H(2)O crystallizes in the rhombohedral space group R-3 with a = 18.0070(6) angstrom, b = 18.0070(6) angstrom, c = 9.7962(5) angstrom, alpha = beta = 90.00 degrees and gamma = 120.00 degrees. In the highly symmetric trinuclear structure, three iron(III) atoms occupy vertices of equilateral triangle and exhibits a quasi-reversible one-electron reduction at E-V2= +0.337 V vs Ag/AgCl (Delta E-p = 0.079 V) due to the [Fe-3(mu(3)-O)(O2CCH2Cl)(6)(H2O)(3)](+)/[Fe-3(mu(3)-O)(O2CCH2Cl)(6)(H2O)(3)] couple. In addition, ascending difference between cathodic and anodic peak potentials (Delta E-p) with the increasing scan rate confirmed the reduction wave to be quasi-reversible. (C) 2012 Elsevier B.V. All rights reserved.