The Structure of the Monomeric Dioxygen Adduct of Vitamin B12r. A Single Crystal EPR Study
The low temperature (−190°C) structure of superoxocobalamin (B12rO2) has been determined from EPR data of vitamin B12b single crystals doped with both B12r and B12rO2. Magnetic data of B12r and B12rO2 (B 12r 17 O2) will be presented and discussed. The strong temperature dependence of the spectra will be traced back to motional effects.