Synthesis and structural characterisation of the 3,5-di-tert-butyl-1,2,4-triphospholyl complexes of monovalent gallium and thallium, [M(η5-P3C2Bu2t)], M=Ga, Tl

Treatment of a metastable toluene–THF solution of GaBr with KP3C2Bu2t led to the monomeric triphospholyl gallium(I) complex [Ga(η5-P3C2Bu2t)] (3). The corresponding thallium complex [Tl(η5-P3C2Bu2t)] (4) was prepared in a similar manner by treatment of TlCl with [Li(tmeda)2][(P3C2Bu2t)]. Both complexes, which are monomeric in solution and in the gas phase, were characterised by mass spectrometry and multinuclear NMR spectroscopy. X-ray structure analyses of both complexes showed them to consist of weakly interacting monomeric half sandwich units in the solid state.