Reaction of trimethylgallium with tricarbonyl-η5-cyclopentadienyl-hydridotungsten and with dicarbonyl-η5-cyclopentadienylhydrido(triphenylphosphine)tungsten. Crystal and molecular structure of µ3-gallio-tris(tricarbonyl-η5-cyclopentadienyltungsten)

Abstract

Trimethylgallium reacts with hydrides [(C₅H₅)W(CO)₂LH][(6) L = CO or (7) L = PPh₃] to give [(C₅H₅)W(CO)₂L-(GaMe₂)][(2) L = CO or (5) L = PPh₃]. (2) Decomposes in hot hydrocarbon solution with formation of [{(C₅H₅)W(CO)₃}₂GaMe], (3), and [{(C₅H₅)W(CO)₃}₃Ga], (4). I.r. evidence suggests that (2) and (3), unlike [{(C₅H₅)W(CO)₃AlMe₂}₂], do not have –C–O– bridges. An X-ray study of (4) shows that it crystallises in space group P2₁/n with a= 13.464(4), b= 17.724(5), c= 11.296(3)Å, β= 101.72(2)°, Z= 4 (R 0.078 for 2791 reflections). The co-ordination at gallium is planar, and the three tungsten neighbours are at 2.739(3)Å.