Correlation between quadrupole splitting (Delta) and the theta angle (C-Sn-C) in five-coordinate diphenyltin(IV) complexes. X-ray crystal structures of [Ph2Sn(hacm)] and [Ph2Sn(hacmm)] containing O,N,S-tridentate N-4-heterocyclic thiosemicarbazones

2-Hydroxyacetophenone N-4- morpholylthiosemicarbazone (H(2)hacm) and 2-hydroxyacetophenone N-4-2,6-dimethylmorpholylthiosemicarbazone (H(2)hacmm) form stable five-coordinate complexes of the compositions [Ph-2(hacm)] and [Ph2Sn(hacmm)], respectively, which were characterized by elemental analysis and spectroscopic (i.r., n.m.r. and Mossbauer) studies. Both complexes and the H(2)hacm ligand were also studied by single crystal X-ray diffraction. The X-ray structures determination of complexes revealed the presence of neutral molecules in which the tin(IV) atoms exhibit distorted trigonal bipyramidal (TBP) geometry, with the O,N,S-tridentate bifunctional behavior of the ligand. The C-Sn-C angles were calculated using a correlation between Mossbauer and X-ray data based on the point-charge model