Ruthenium bipyridine complexes:: synthesis and characterisation of Ru(tmbpy)(CO)2Cl2, Ru(dmbpy)(CO)2Cl2 and [Ru(dmbpy)(CO)2Cl]2

Ruthenium carbonyl complexes with methyl substituted 2,2'-bipyridine ligands have been synthesised. [Ru(CO)(3)Cl-2](2) reacts with 4,4',5,5'-tetramethyl 2,2'-bipyridine (tmbpy) and 4,4'-dimethyl 2,2'-bipyridine (dmbpy) in THF to form mononuclear cis-CO, cis-Cl complexes, whereas in ethylene glycol/octanol solution the product with dmbpy is dimeric. The dimeric complex [Ru(bpy)(CO)(2)Cl](2) has been re-measured and refined in space group P2/c. The complexes have been characterised by spectroscopic studies and X-ray diffraction measurements: Ru(tmbpy)(CO)(2)(Cl)(2) (1), orthorhombic, space group P2(1)2(1)2(1), a = 9.372(2) Angstrom, b = 12.779(1) Angstrom, c = 15.320(3) Angstrom, Z = 4; Ru(dmbpy)(CO)(2)(Cl)(2) (2), monoclinic, space group P2(1)/c, a = 11.754(4) Angstrom, b = 12.920(3) Angstrom, c = 14.245(3) Angstrom, beta = 111.74(2)degrees Z = 4; [Ru(dmbpy)(CO)(2)Cl](2) (3), monoclinic, space group C2/c, a = 21.485(7) Angstrom, b = 11.900(4) Angstrom, c = 14.924(3) Angstrom, beta = 130.30(3)degrees, Z = 4. (C) 1998 Elsevier Science S.A.