Synthesis, structure, and properties of a pentanuclear cobalt(III) coordination cluster

Abstract

The synthesis, X-ray structure and properties of a pentanuclear cobalt(III) coordination cluster [{L(O2CCH3)Co2O(OCH3)2}2Co](ClO4)3 (1) (L- = 2,6-bis((3-aminopropylimino)methyl)-4-methylphenolate) are described. The dinucleating L- is coordinated with two cobalt(III) centers to form the {L(O2CCH3)Co2O(OCH3)2} unit, where each metal center is in a distorted octahedral N2O4 environment. The oxo and the methoxo ligands of these two dinuclear units assemble a distorted octahedral O6 coordination sphere around the central cobalt(III). Elemental analysis and spectroscopic (IR, NMR, UV-vis, and HRMS) features are consistent with the pentanuclear structure of the complex. The diamagnetic complex is a 1: 3 electrolyte in solution. It is redox-active and displays a metal-centered reduction at E1/2 = -0.04 V (vs. Ag/AgCl).