CHEMISTRY OF POLYNUCLEAR METAL-COMPLEXES WITH BRIDGING CARBENE OF CARBYNE LIGANDS .108. SYNTHESIS AND REACTIONS OF THE ALKYLIDYNETUNGSTEN COMPLEXES [W(=CR) (CO)2((F3B)C(PZ)3)] (R = ME OR C6H4ME-4,PZ = PYRAZOL-1-YL) AND THEIR USE AS REAGENTS FOR PREPARING DI-METAL COMPOUNDS AND TRI-METAL COMPOUNDS

Treatment of thf (tetrahydrofuran) solutions of the salts [W( = CR)(CO)2{HC(pz)3}][BF4] [R = Me or C6H4Me-4, HC(pz)3 = tris(pyrazol-1-yl)methane] with LiBu, followed by BF3.Et2O, affords the neutral alkylidynetungsten complexes [W(= CR)(CO)2{(F3B)C(pz)3}]. The species with R = Me was also prepared from the reaction between [W(= CMe)Br(CO)4] and Li[(F3B)C(pz)3] in thf. The compounds [W(= CMe)(CO)2{(F3B)C(pz)3}] and [Pt(nb)(PMe2Ph)2] (nb = norborene = bicyclo[2.2.1]heptene) react in thf to yield the dimetal complex [WPt(mu-CMe)(CO)2(PMe2Ph)2{(F3B)C(pz)3}], and the latter with [AuR(tht)] (R = Cl or C6F5, tht = tetrahydrothiophene) or CuCl in CH2Cl2, yields the trimetal species [WPtMR(mu-3-CMe)(CO)2(PMe2Ph)2{(F3B)C(pz)3}] (M = Au, R = Cl or C6F5; M = Cu, R = Cl), respectively. Addition of [Pt(cod)2] (cod = cycloocta-1,5-diene) to a thf solution of [W(= CMe)(CO)2{(F3B)C(pz)3}] gives a chromatographically separable mixture of the compounds [WPt(mu-CMe)(CO)2-(cod){(F3B)C(pz)3}], [W2Pt(mu-CMe)2(CO)4{(F3B)C(pz)3}2] and [WPt2(mu-3-CMe)(CO)2(cod)2{(F3B)C(pz)3}]. The complexes [WPt(mu-CC6H4Me-4)(CO)2(cod){(F3B)C(pz)3}] and [WPt2(mu-3-CC6H4Me-4)(CO)2(cod)2{(F3B)C(pz)3}] have been similarly obtained from [Pt(cod)2] and [W(= CC6H4Me-4)(CO)2{(F3B)C(pz)3}]. Treatment of the latter with [Pt(nb)3] in thf affords the trimetal compound [W2Pt(mu-CC6H4Me-4)2(CO)4{(F3B)C(pz)3}2]. The NMR data (H-1, C-13-{H-1} and P-31-{H-1}) for the new compounds are reported and discussed.