LAUSR

The halocarbyne complexes [M(CX)(CO)2(Tp*)] (M = Mo, W; X = Cl, Br; Tp* = hydrotris(dimethylpyrazolyl)borate) react with [AuCl(SMe2)], [Pt(η2-H2CCH2)(PPh3)2] or [Pt(η2-nbe)3] (nbe = norbornene) to furnish rare examples of μ2-halocarbyne complexes [MAu(μ2-CX)Cl(CO)2(Tp*)], [MPt(μ2-CCl)(CO)2(PPh3)2(Tp*)] and [W2Pt(μ2-CCl)2(CO)4(Tp*)2]. The complex [WPt(μ2-CCl)(CO)2(PPh3)2(Tp*)] spontaneously rearranges to the μ2-carbido complex [WPt(μ2-C)Cl(CO)2(PPh3)2(Tp*)] during silica-gel chromatography. One phosphine ligand of [WPt(μ2-CCl)(CO)2(PPh3)2(Tp*)] is readily substituted by CO to afford [WPt(μ2-CCl)(CO)3(PPh3)(Tp*)]. These μ2-halocarbyne complexes have been interrogated by spectroscopic, crystallographic and computational methods, the latter by reference to data for terminal halocarbyne precursors [M(CX)(CO)2(Tp*)].