NMR-STUDY OF ELECTRON-TRANSFER BETWEEN PARAMAGNETIC-COMPLEXES - KINETICS OF THE SELF-EXCHANGE REACTION [FE3O(O2CCME3)(6)(PY)(3)](+ 0) (PY =PYRIDINE)/

The kinetics of the electron transfer self-exchange reaction [Fe3O(O2C CMe3)(6)(py)(3)](+) + [Fe3O(O2CCMe3)(6)(py)(3)]reversible arrow [Fe3O( O2CCMe3)(6)(py)(3)] + [Fe3O(O2CCMe3)(6)(py)(3)](+) have been measured by NMR line broadening. Both reactants are paramagnetic and it was pos sible to measure broadening of lines of each component by exchange wit h the other. In dichloromethane at 23 degrees C the second-order rate constant is (3.7+/-0.1) x 10(4) M-1 s(-1). The ligand exchange reactio ns of [Fe3O(O2CCMe3)(6)(py)(3)](pi+) with pyridine are rapid for the m ixed-valence complex (n = 0) but slow for the oxidised complex (n = 1) .