Chemistry of polynuclear metal complexes with bridging carbene or carbyne ligands. Part 105. Alkylidyne tungsten and molybdenum complexes with pyrazolylmethane ligands
Abstract
The alkylidynemetal complexes [M(CR)(CO)2{HC(pz)3}][BF4][HC(pz)3= tris(pyrazol-1-yl)methane; M =W, R =Me, C6H4Me-4, or C6H3Me2-2,6; M = Mo, R = Me or C6H4Me-4], [W(CMe)(CO)2{MeC(pz)3}][BF4][MeC(pz)3=1,1,1 -tris(pyrazol-1 -yl)ethane], and [W(CMe)(CO)3{H2C(pz)2}][BF4][H2C(pz)2= bis(pyrazol-1-yl)methane] have been prepared by treating the complexes [MBr(CR)(CO)4] in thf (tetrahydrofuran) with TIBF4 and HC(pz)3, MeC(pz)3, and H2C(pz)2, respectively. Reactions of the salts [W(CR)(CO)2{HC(pz)3}][BF4](R = Me or C6H4Me-4) with the compounds [Co2(CO)8], [Pt(nb)3](nb = norbornene = bicyclo[2.2.1]heptene), and [Pt(nb)(PMe2Ph)2] afford the mixed-metal complexes [WCo2(µ3-CR)(CO)8{HC(pz)3}][BF4], [W2Pt(µ-CR)2(CO)4{HC(pz)3}2][BF4]2, and [WPt(µ-CR)(CO)2(PMe2Ph)2{HC(pz)3}][BF4], respectively. A trimetal complex [WPtAu(C6F5)(µ3-CMe)(CO)2(PMe2Ph)2{HC(pz)3}][BF4] has been prepared by addition of [Au(C6F5)(tht)](tht = tetrahydrothiophene) to [WPt(µ-CMe)(CO)2(PMe2Ph)2{HC(pz)3}][BF4] in thf. The n.m.r. data (1H, 13C-{1H}, and 31P-{1H}) for the new compounds are reported and discussed in relation to the structures proposed.