Isonitrile μ2-carbido complexes

The mu-carbido complex [WPt(mu-C)Br(CO)(2)(PPh3)(2)(Tp*)] (Tp = hydrotris(dimethylpyrazolyl)borate) undergoes substitution of one phosphine ligand with isonitriles to afford complexes [WPt(mu-C)Br(CNR) (CO)(2)(PPh3)(Tp*)] (R = tBu, C6H3Me2-2,6, C6H2Me3-2,4,6). For aryl but not alkyl isocyanides disubstitution follows to afford [WPt(mu-C)Br(CNR)(2)(CO)(2)(Tp*)] (R = C6H2Me2-2,6, C6H2Me3-2,4,6). The bis(isonitrile) derivatives, including [WPt(mu-C)Br(CNtBu)(2)(CO)(2)(Tp*)], may also be prepared from the reactions of triangulo-[Pt-3(CNR)(6)] with [W(=CBr)(CO)(2)(Tp*)]. Bis-and tris(dimethylpyrazolyl)borate pro-ligand salts replace the bromide and one phosphine in [WPt(mu-C)Br(CNC6H2Me3)(CO)(2)(PPh3)(Tp*)] or the bromide and one isonitrile in [WPt(mu-C)Br(CNC6H2Me3)(2)(CO)(2)(Tp*)] to afford [WPt(mu-C)(CNC6H2Me3)(CO)(2)(Tp*)(L)] (L = kappa(2)- Tp*, dihydrobis(pyrazolyl)borate). Structural, spectroscopic and computational data for the complexes are discussed to interrogate the nature of the W=C-Pt carbido bridge by analogy with a range of other spC(1) and sp-B-1 ligands (C=N, C=CH, C=P, C=As, C=Sb, C=NO, B=O, B=NH and BvCH(2)).