Radiation effects in Sn(IV) complexes: A Mössbauer spectroscopic and radiochemical study

Chemical after effects of neutron induced nuclear transformations have been investigated in a variety of Sn(IV) complexes using radiochemical,119Sn Mössbauer absorption spectroscopy and powder X-ray diffraction techniques. The retention values for (CH3)2SnCl2NN (where NN are the neutral nitrogen coordinating bidentate ligands) complexes have been found to be ⩽ 0.05 with respect to113Sn andl7mSn activity and independent of dose up to a neutron fluence of 1.2 × 1017 n cm−2. Unlike this the complexes HSnDTPA, NaSnDTPA and SnEDTA showed a retention of approximately 0.75 with respect to both these tin isotopes. Mössbauer absorption spectra of reactor irradiated samples showed a macroscopic degradation of the matrix. For (CH3)2SnCl2NN complexes the radiation induced quadrupole doublet, exhibiting σ ≃ 1.0 mm sec−1 and ΔEq ≃ 2.5 mm sec−1, is characteristic of coordinated Sn(IV) species. Unlike this the additional doublet observed for DTPA and EDTA complexes is characteristic of Sn+2 state.60Co gamma irradiation also produced essentially similar species as revealed by Mössbauer spectroscopy. The possible role of thermal neutrons towards macroscopic damage has been discussed.