Trichloro-, mono-, di- and tri-organotin(IV) derivatives of hydridotris-(4-methylpyrazol-1-yl)borates

Tin(IV) complexes of general formula SnR(n)Cl(3-n)[HB(mpz)(3)] (R = Me or Ph; n = 0-2; mpz = 4-methylpyrazolyl) have been synthesised and characterised by IR, far-IR, H-1, C-13, Sn-119 NMR and; Sn-119 Mossbauer spectroscopy. Their. stability towards self-decomposition decreases with increasing number of Sn-bonded aryl or alkyl groups. In addition, triorganotin(rv) complexes of the same ligand as well as of [HB(pz)(3)](-) and [HB(dmpz)(3)] (pz = pyrazolyl, dmpz = 3,5-dimethylpyrazolyl) have been synthesised and characterised by IR and NMR techniques but,due to their low stability (even in the solid state), could not be characterised by Mossbauer spectroscopy. Both the crystal structures of SnCl3 [HB(mpz)(3)] and SnPhCl(2) [HB(mpz)(3)] show the tin atom in a skewed octahedral environment. The structure-of the deboronated adduct SnMe(2)Cl(2)(Hmpz)(2), obtained from attempted recrystallisation of SnMe(2)Cl[HB(mpz)(3)], in which the Cl, the Me and the N-donors are in the all-trans configuration, has been determined.