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)]

摘要

The complexes [(dppp)Pt{(μ-C2C5H4N)W(CO)4-(PR3)}2] (dppp = Ph2P(CH2)3PPh2;PR3 = PPh3 (1), P(4-XC6-H4)3 (X = Me (2), OMe (3), F (4)) P(NMe2)3 (5)) were prepared from t(dppp)Pt(C2C5H4N)2] and cis-[W(CO)4(PR3)(CH3CN)] and were characterized by ~1H, ~(13)C, ~(15)N, ~(31)P, ~(183)W and ~(195)Pt 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-Me-C6H4)3)(CH3CN)] and was characterized by NMR (~1H,~(13)C, ~(15)N, ~(31)P, ~(103)Rh and ~(183)W) 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.