Electrochemically Active Copper Complexes with Pyridine-Alkoxide Ligands.

Pyridine-alkoxide (pyalk) ligands that support transition metals have been studied for their use in electrocatalytic applications. Herein, we used the pyalk proligands diphenyl(pyridin-2-yl)methanol ([H]^PhPyalk, L1), 1-(pyren-1-yl)-1-(pyridin-2-yl)ethan-1-ol ([H]^PyrPyalk, L2), 1-(pyridine-2-yl)-1-(thiophen-2-yl)ethan-1-ol ([H]^ThioPyalk, L3), and 1-(ferrocenyl)-1-(pyridin-2-yl)ethan-1-ol ([H]^FePyalk, L4) to synthesize Cu^II complexes that vary in nuclearity and secondary coordination sphere. Also, the proligand 1-(ferrocenyl)-1-(5-methoxy-pyridin-2-yl)ethan-1-ol ([H]^FeOMePyalk, L5) was synthesized with a methoxy substituted pyridine; however, the isolation of a Cu^II complex ligated by L5 was not possible. Under variable reaction conditions, the pyalk ligands reacted with Cu^II precursors and formed either mononuclear or dinuclear Cu^II complexes depending on the amount of ligand added. The resulting complexes were characterized by single crystal X-ray diffraction, elemental analysis, and cyclic voltammetry. [ABSTRACT FROM AUTHOR]