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 chemical after-effects accompanying the electron capture decay process of Co-57 within an isostructural series of Co-57-doped diaquadiformato complexes of general formula Co-57:M(HCO2)2 . 2H(2)O (M = Mn, Fe, Co, Ni, Cu, Zn). The experimental results are analysed within the framework of the self-radiolysis model, adjusted to allow for the appropriate influence of the host lattice on the stabilization scheme of the nucleogenic Fe-57 species. In line with previous investigations of these processes in other carboxylate-type complexes, large amounts of Fe-III are observed in the nickel-based compound, corroborating the marked propensity of host matrices with more compact structures to stabilize smaller ions in the sterically hindered substitutional sites