Preparation and NMR study of trimetallic complexes of platinum and tungsten bridged by 4-pyridylacetylide and a binuclear complex of rhodium and tungsten bridged by 2-(4-pyridyl)thiazole-4-carboxylate (PTC): structure of [(Ph3P)2Rh(H)2(μ-PTC)W(CO)4(P(4-MeC6H4)3)

Abstract

The complexes [(dppp)Pt{(μ-C2C5H4N)W(CO)4(PR3)}2] (dppp = Ph2P(CH2)3PPh2; PR3 = PPh3 (1), P(4-XC6H4)3 (X = Me (2), OMe (3), F (4)) P(NMe2)3 (5)) were prepared from [(dppp)Pt(C2C5H4N)2] and cis-[W(CO)4(PR3)(CH3CN)] and were characterized by 1H, 13C, 15N, 31P, 183W and 195Pt NMR spectroscopy. The complex [(Ph3P)2Rh(H)2(μ-PTC)W(CO)4(P(4-MeC6H4)3)] (6) was prepared similarly, from [(Ph3P)2Rh(H)2(PTC)] (thiazole nitrogen and carboxylate oxygen attached to the metal) and cis-[W(CO)4(P(4-MeC6H4)3)(CH3CN)] and was characterized by NMR (1H, 13C, 15N, 31P, 103Rh and 183W) and by X-ray crystallography, which shows π–π interactions between the bridging pyridyl and a phenyl group from a phosphine on each metal. In complexes 1–5, there is little variation in the platinum chemical shift, indicating that electronic influences through the pyridylacetylide bridge are minimal. A bimetallic complex of rhodium and tungsten bridged by 2-(4-pyridyl)-thiazole-4-carboxylate is reported together with an NMR spectroscopic study of a series of trinuclear complexes of platinum and tungsten bridged by 4-pyridylacetylide.