Redox and acid-base effects in the oxo-bridged trinuclear ruthenium isobutyrate system

CHED 1219

Jennifer M. Schlough, schlough@hartford.edu and Laura E. Pence, LPence@hartford.edu. Department of Chemistry, University of Hartford, 200 Bloomfield Ave, West Hartford, CT 06117
Trinuclear m3–oxo-bridged ruthenium–carboxylate clusters have been studied in great detail due to their strong electronic and magnetic interactions, as well as their extensive redox and catalytic properties. The complexes are characterized by a triangular arrangement of metal atoms with a central oxo ligand, carboxylate ligands bridging above and below each side of the triangle and an axial solvent ligand. Developing standard procedures for the general synthesis of additional triruthenium oxo-bridged carboxylate complexes beyond the well-known acetate cluster is a focus of our research group. Our investigations have revealed two procedures leading to different forms of the ruthenium isobutyrate complex, the blue product [Ru3O(O2C4H7)6(py)3]+, and a green product, hypothesized to be [Ru3O(O2C4H7)6(OH)(py)2]. These species have been characterized using nuclear magnetic resonance, cyclic voltammetry, and X-ray diffraction. Details of the synthetic conditions used to optimize the production of one product over the other will be discussed.