Complexes of copper(I) and silver(I) with bis(methimazolyl)borate and dihydrobis(2-mercaptothiazolyl)borate ligands

The complexes [Cu(Bm(Me))](3) center dot 0.77C(4)H(8)O (1), [(Bm(Me)) Ag(PPh3)] (2) and [M{kappa(3)-H(mu-H)B(tiaz)(2)}(PPh3)] (M= Cu (3), Ag (4); BmMe = bis(2-mercapto-1-methylimidazolyl)borate, H2B(tiaz)(2) = dihydrobis( 2-mercaptothiazolyl) borate) have been prepared and characterised by X-ray crystallographic and spectroscopic methods. The presence of M center dot center dot center dot H-B interactions in these species has been investigated using infrared spectroscopy and crystallography. In [Cu( Bm(Me))](3), the triangular array of three trigonal-planar copper atoms is coordinated by three chelating and bridging (Bm(Me))(-) ligands, and has an unusual, highly unsymmetrical arrangement with one short Cu-Cu distance; this is the first structurally authenticated Bm(Me) complex with a nuclearity greater than two. In complexes 2-4, the metal atom is found in a distorted trigonal-planar geometry, bound by a terminal phosphine ligand and two sulfur atoms of a chelating ligand, supplemented by an M center dot center dot center dot H-B interaction, which appears to be a common feature in the coordination chemistry of the (Bm(Me))(-) and [H2B(tiaz)(2)](-) ligands; compounds 1 - 4 are the first reported complexes of copper( I) and silver( I) with any bis(2-mercaptoimidazolyl) borate ligand or with H2B(tiaz)(2).