FE-57 EMISSION MOSSBAUER STUDY OF ELECTRON-CAPTURE AFTER-EFFECTS IN CO-57-DOPED DIAQUADIFORMATO COMPLEXES OF THE FIRST TRANSITION SERIES

Emission Mossbauer spectroscopy is applied to the investigation of che mical after-effects accompanying the electron capture decay process of Co-57 within an isostructural series of Co-57-doped diaquadiformato c omplexes of general formula Co-57:M(HCO2)2 . 2H(2)O (M = Mn, Fe, Co, N i, Cu, Zn). The experimental results are analysed within the framework of the self-radiolysis model, adjusted to allow for the appropriate i nfluence of the host lattice on the stabilization scheme of the nucleo genic Fe-57 species. In line with previous investigations of these pro cesses in other carboxylate-type complexes, large amounts of Fe-III ar e observed in the nickel-based compound, corroborating the marked prop ensity of host matrices with more compact structures to stabilize smal ler ions in the sterically hindered substitutional sites.