COMPLEXES OF DIBUTYLDIHALOTIN(IV) WITH IMIDAZOLE AND PYRAZOLE - THE CRYSTAL-STRUCTURE OF DIBUTYLDICHLOROBIS(PYRAZOLE)TIN(IV)

Complexes of the type [SnBu2X2L2] (X=Cl or Br; L=HIm or HPz) were obtained from the reaction of SnBU2X2 with imidazole (HIm) or pyrazole (HPz). The structure of dibutyldichlorobis (pyrazole)tin(IV) was determined by X-ray diffraction. The crystal consists of discrete all-trans SnBu2Cl2(HPz)2 units with the metal atom octahedrally coordinated to two butyl carbons, two Cl atoms and two pyrazole rings. The pyrazole ligands are bound intra- and inter-molecularly to the chlorine atoms. IR data suggest similar trans-stereochemistry for the other compounds prepared. The C-13 NMR spectra indicate that [SnBu2X2(HPz)2] dissociates completely in DMSO-d6 but only partially in CDCl3.