Electrochemical analysis of biocapped triangular cobalt cyclopentadienyl clusters, [Co3(.eta.5-C5H5-xMex)3(.mu.3-X)(.mu.3-Y)]n (x = 0, 1, 5), containing mixed .pi.-acceptor X and .pi.-donor Y capping ligands [X = CO, NO; Y = NSiMe3, NC(O)NH2, NH]: pronounced variations in redox behavior as a function of coordinating ligands |