EMISSION MOSSBAUER STUDIES ON COBALT CARB ONYL-COMPLEXES LABELED WITHCO-57

Three different Co-57-doped cobalt carbonyl complexes, Na[CO(CO)4], CO 2(CO)8 and CH3C(=O)CO(CO)3PPh3 representing a formal valence state of cobalt -1, 0, and +1, respectively, were prepared and studied by emiss ion Mossbauer spectroscopy. As a result of aftereffects of the EC deca y of Co-57, Fe2+ and Fe3+ states could be identified in the Mossbauer spectra with hardly any dependence on the initial valence state of cob alt. This observation is explained by assuming the fragmentation of th ese molecules as a result of the electron loss caused by the Auger ion ization of the nucleogenic Fe-57 atom.