Electronic interactions in diyne Co-2(CO)(6) complexes

Electrochemical criteria are used to evaluate the electronic interaction between redox centres in the pi-conjugated diyne complexes {RC=C[Co-2(CO)(6)]C=C[Co-2(Co)(6)]R) and (RC-C[Co-2(CO)(6)]-(S)-C=C[Co-2(CO)(6)]R} (R=Ph, Pc) where the aromatic spacer S is phenyl, napthalene or anthracene. Voltammetry at microelectrode, differential pulse techniques and low temperature measurements are used to obviate the chemical complications following the primary redox process. A mechanism is proposed which successfully simulates the electrochemical data.