Cyclopentadienyl-ruthenium and -osmium chemistry. XXVII. X-ray structures of Ru(CCPh)(dppe)(η-C₅H₅) and of [Ru(L)(PPh₃)₂(η-C₅H₅)]X (L = C(OMe)Et, X = PF₆; L = CCMePh, X = I)

Abstract

Determinations of the crystal structures of the acetylide Ru(CCPh)(dppe)(η-C5H5), the vinylidene [Ru(CCMePh)(PPh3)2(η-C5H5)]I and the carbene [Ru{C(OMe)Et}(PPh3)2(η-C5H5)][PF6], have enabled comparison of the RuC(α) bonds in these and a number of related complexes. Cationic complexes have RuC bonds shorter (by 0.05-0.1 Å) than values expected on the basis of normal covalent radii, but in the case of vinyl and acetylide complexes there does not appear to be any significant shortening of the RuC bond which can be ascribed to back-bonding from the metal to the unsaturated carbon-bonded ligand. Ru(CCPh)(dppe)(η-C5H5) crystallises in the monoclinic space group P21/n, with a 14.642(4), b 14.018(3), c 16.490(4) Å, β 105.08(2)°, Z 4; [Ru(CCMePh)(PPh3)2(η-C5H5)]I crystallises in the orthorhombic space group P212121, a 12.612(4), b 15.607(3), c 22.357(6) Å, Z 4; [Ru{C(OMe)Et}(PPh3)2(η-C5H5)][PF6 crystallises in the orthorhombic space group P212121, a 11.999(3), b 14.948(1), c 22.342(3) Å, Z 4. For 4841, 2614 and 3299 data (I > 2.5σ(I), respectively, refinements converged with R, Rw values of 0.038 and 0.048, 0.047 and 0.053, and 0.040 and 0.044 for the three complexes. Show more