On the optical spectrum of cobalt(III) in the active sites of enzymes

The optical absorption spectra of cobalt(III) carbonic anhydrase and several of its derivatives was recorded. The rule of average environment was tested for the first spin-allowed dd band in the spectra of cobalt(III) inorganic complexes and was found to be useful in predicting the positions of the absorption peaks in various complexes. It is shown how, using this rule, the optical spectra can assist in the identification of the ligands bound to cobalt(III) in the active sites of enzymes.