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

Abstract

Tin(IV) complexes of general formula SnR_nCl_{3 –n}[HB(mpz)₃](R = Me or Ph; n= 0–2; mpz = 4-methylpyrazolyl) have been synthesised and characterised by IR, far-IR, ¹H, ¹³C, ¹¹⁹Sn NMR and ¹¹⁹Sn Mössbauer spectroscopy. Their stability towards self-decomposition decreases with increasing number of Sn-bonded aryl or alkyl groups. In addition, triorganotin(IV) 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 Mössbauer spectroscopy. Both the crystal structures of SnCl₃[HB(mpz)₃] and SnPhCl₂[HB(mpz)₃] show the tin atom in a skewed octahedral environment. The structure of the deboronated adduct SnMe₂Cl₂(Hmpz)₂, obtained from attempted recrystallisation of SnMe₂Cl[HB(mpz)₃], in which the Cl, the Me and the N-donors are in the all-trans configuration, has been determined.