Synthesis of new heteronuclear complexes with bridging carbyne ligands between tungsten and gold. X-Ray crystal structure of [AuW(µ-CC6H4Me-4)(CO)2(bipy)(C6F5)Br]

Abstract

The compound [W(CR)(CO)₂(η-C₅H₅)](R = C₆H₄Me-4)(1) reacts with [Au(C₆F₅)(tht)](tht = tetrahydrothiophene) to give the tungsten–gold complex [AuW(µ-CR)(CO)₂(C₆F₅)(η-C₅H₅)](2), and the compound [W(CR)(CO)₂(bipy)Br](bipy = 2,2′-bipyridine) reacts similarly with [Au(C₆F₅)(tht)] and [AuCl(tht)] to give the analogous complexes [AuW(µ-CR)(CO)₂(bipy)X(Br)](4; X = C₆F₅) and (5; X = Cl). In complex (4), which has been structurally characterized by X-ray diffraction, there is a Au–W bond asymmetrically bridged by a CR group; the W atom carries a chelating bipyridine, one bromide, and two terminal carbonyls, while the gold carries a C₆F₅ group. The heterometallic complex (2) reacts with the reagents [Cu(thf)(η-C₅Me₅)] and [Pt(PMe₃)₂(C₂H₄)] to give respectively the trimetallic compounds [AuCuW(µ₃-CR)(CO)₂(C₆F₅)(η-C₅H₅)(η-C₅Me₅)](6) and [AuPtW(µ₃-CR)(CO)₂(PMe₃)₂(C₆F₅)(η-C₅H₅)](7). The latter compound can also be prepared by treating [Au(C₆F₅)(tht)] with [PtW(µ-CR)(CO)₂(PMe₃)₂(η-C₅H₅)].