The cyclic voltammetric behavior for a series of compounds containing (h⁵-C₅H₅)Co(a,b)C₆H_4, where a and b are permutations of N, O and S, will be described.  The reductions for the species were reversible and followed the trend (NH, NH) < (NH, O) < (NH, S) < (S, S) < (O,O) with the (NH, NH) compound having the most negative potential.  Irreversible oxidations were found for (NH, S), (S, S), and (O, O) while what appears to be two one-electron reversible oxidations were found for (NH, NH) and (NH, O).  The electrochemical behavior will be related to the bonding characteristics within the benzene ligands and nuclear quadrupole spectroscopic results.