Dihalodimethyltin(IV) complexes of 2-(pyrazol-1-ylmethyl)pyridine

Reaction of dichloro- and dibromodimethyltin(IV) with 2-(pyrazol-1-ylmethyl)pyridine (PMP) afforded [SnMe2Cl2(PMP)] and [SnMe2Br2(PMP)] respectively. The new complexes were characterized by elemental analysis and mass spectrometry and by IR, Raman and NMR (H-1, C-13) spectroscopies. Structural studies by X-ray diffraction techniques show that the compounds consist of discrete units with the tin atom octahedrally coordinated to the carbon atoms of the two methyl groups in a trans disposition (Sn-C = 2.097(5), 2.120(5) Angstrom and 2.110(6), 2.121(6) Angstrom in the chloro and in the bromo compounds respectively), two cis halogen atoms (Sn-Cl = 2.4908(16), 2.5447(17) Angstrom; Sn-Br = 2.6875(11), 2.7464(9) Angstrom) and the two donor atoms of the ligand (Sn-N = 2.407(4), 2.471(4) Angstrom and 2.360(5), 2.455(5) Angstrom). In both cases, the Sn-N(pyridine) bond length is markedly longer than the Sn-N(pyrazole) distance. Copyright (C) 2003 John Wiley Sons, Ltd.