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 E_1/2 = −0.04 V (vs. Ag/AgCl).

Keywords:

• Pentanuclear complex
• Cobalt(III)
• Dinucleating ligand
• Crystal structure
• Physical properties

Acknowledgements

S. Maloth and S.K. Kurapati thank the Council of Scientific and Industrial Research for research fellowships.

Additional information

Funding

This work was supported by the Department of Science and Technology (IYC grant and FIST program); and the University Grants Commission (CAS program).