A SN-119 MOSSBAUER STUDY OF HEPTACOORDINATED TIN COMPLEXES WITH MULTIDENTATE LIGANDS

Three novel heptacoordinated tin complexes with multidentate ligands were prepared and studied by Mossbauer spectroscopy. The complexes were identified as [MeSnCl(Hdaptsc)]Cl MeOH, [MeSnCl(H(2)dapsc)]Cl-2 2H(2)O and [ClSnCl(Hdaptsc)]Cl, where H(2)daptse = 2,6-diacetylpyridinebis (thiosemicarbazone) and H(2)dapse = 2,6-diacetylpyridinebis (semicarbazone). The structures of the first two complexes were determined by X-ray crystallography. The ligand H(2)dapse originated a fourth complex, which was characterised as [(Me(2)SnCl(2))(2)(H(2)dapsc)] in which the two Sn atoms are probably hexacoordinated, as suggested by Mossbauer data. The isomer shifts and the quadrupole splittings of the complexes are consistent with the structural interpretation, and correlate well with other literature examples and with X-ray data whenever available. The correlation between Mossbauer results and structural information is important considering the paucity of published data for heptacoordinated species.