Resonance raman studies of phenolate-bridged binuclear copper complexes. relevance to hemocyanin and tyrosinase

Phenolate-bridged binuclear complexes serve as models for proposed active site structures in the met forms of hemocyanin and tyrosinase. The resonance Raman spectra of these complexes have been investigated and compared with corresponding mononuclear analogues. The phenolate v_C-o^'s for the binuclear complexes occur above 1300 cm⁻¹ 11and are significantly higher in energy than those for the mononuclear analogues. Comparisons of the crystal structures of mononuclear and binuclear complexes suggest that the higher v_C-o values for the binuclear complexes may result from the larger Cu-O-C(Ph) angles enforced by the bridging structure.