Diorganotin(IV) complexes of 2,5-dithiobiurea (H2dtbu).: The crystal structures of Me2Sn(dtbu) and Ph2Sn(dtbu)

The diorganotin(IV) complexes, R2Sn(dtbu) (R=Me 1, n-Bu 2, Ph 3, PhCH2 4; H(2)dtbu=2,5-dithiobiurea), have been synthesized and characterized by IR, H-1, and Sn-119 NMR spectroscopy. The structures of 1 and 3 have been determined by X-ray crystallography. Crystal structures show that both complexes 1 and 3 consist of molecules in which the bideprotonated ligand is N,S,S-bonded, and the tin atom exhibits distorted pentacoordination with small differences between the methyl and phenyl derivatives in bond distances and bond angles. The unusual coordination mode of the dtbu(2-) anion creates four- and five-membered chelate rings. Moreover, the packing of complexes 1 and 3 are stabilized by the hydrogen bonding. (c) 2006 Wiley Periodicals, Inc.