Synthesis, reactivity and solid-state structural studies of new phosphino copper(I) derivatives of hydrotris(3-methyl-2-thioxo-1-imidazolyl)borate

1:1:1 [(R3P)Cu(Tm)] (R=phenyl, cyclohexyl, m- and p-tolyl) or [(R′Ph2P)Cu(Tm)] (R′=methyl or ethyl) triorganophosphine copper(I) adducts, containing the anionic, potential S3 −, face-capping ligand hydrotris(3-methyl-1-imidazolyl-2-thione)borate [Tm]−, were synthesised from K[Tm], CuCl and the corresponding P-donor. No phosphine adduct was obtained when tri-o-tolyl-, tribenzyl-phosphine, triphenylarsine and triphenylantimony were reacted with K[Tm] and CuCl, [Cu(Tm)]n being the product obtained always, in strong excess of the phosphorus donor. The probably polynuclear [Cu(Tm)]n is stable towards Hmimt (3-methyl-1-imidazoline-2-thione), NH3, CS2, H2O and CO; it reacts with pyridine (py) to yield the 1:1:1 adduct [(py)Cu(Tm)]. [Cu(Tm)]n also reacts with H2O2 yielding the poorly soluble derivative [Cu(mimt)]n upon breaking of the BN bond in the azolyl–borate ligand. All of the complexes synthesised were characterised through analytical and spectral (IR, 1H and 31P NMR) measurements. The solid-state structures of [(m-tolyl3P)Cu(Tm)] and [(p-tolyl3P)Cu(Tm)] show the copper atoms to be tetracoordinate with the donor [Tm] behaving as an S3 −, face-capping ligand.