Synthesis and characterization of two new bulky tris(mercaptoimidazolyl)borate ligands and their zinc and cadmium complexes

The sodium salts of the tris(2-mercapto-1-benzylimidazolyl)borate [Tm-Bz](-) and tris(2-mercapto-1-p-totylimidazolyl)borate [Tmp-Tol](-) anions have been readily prepared in very good yield from NaBH4 and 2-mercapto-1-benzylimidazole or 2-mercapto-1-p-tolylimidazole, respectively. These new monoanionic tripodal sulfur-donor ligands have been used to prepare the Group 12 derivatives (Tm-R)MBr (M = Zn, Cd: R = Bz. p-Tol), all of which have been characterized by a combination of analytical and spectroscopic techniques. including electrospray ionization mass spectrometry (ESI MS) and, in the case of both benzyl-substituted derivatives, single-crystal X-ray diffraction. (C) 2001 Published by Elsevier Science Ltd.