ORGANOTIN(IV) POLYPYRAZOLYLBORATES .12. HYDRIDOTRIS(4-BROMO-1H-PYRAZOL-1-YL)BORATES - CHARACTERIZATION, MOSSBAUER STUDY AND X-RAY CRYSTAL-STRUCTURE OF MECL(2)SN(4-BRPZ)(3)BH

A series of tin(IV) and organotin(IV) hydridotris(4-bromo-1H-pyrazol-1 -yl)borates has been prepared. The compounds of general formula R(n)Sn Cl(4-n-1)[HB(4-Br-pz)(3)] (where R = Me or Ph, n = 0, 1, 2, or 3) are rigid in solution and contain a six-coordinate tin(IV) site with a tri dentate ligand. They were characterised by IR,H-1, C-13, Sn-119 NMR, a nd Sn-119 Mossbauer spectroscopy. Their stability towards self-decompo sition decreases with increasing number of Sn-bonded aryl or alkyl gro ups, The compound MeCl(2)Sn[HB(4-Br-pz)(3)] crystallises in the space group R (3) over bar (no. 148), trigonal, with a = 35.520(2), b = 35.5 20(2), and c = 8.688(1)Angstrom, gamma = 120 degrees.