A synthetic and structural study of oxorhenium(V) complexes with mixed didentate (O,O)-terdentate(O,N,N) ligands

The reaction of cis-[ReOCl2(L-3)] (L-3(-) = terdentate O,N,N-donor ligand 2-[[{2-(2-pyridinyl)ethyl}amino]methyl]phenolate) with ethylene glycol (H(2)eg) in acetonitrile led to the isolation of [ReO(L-3)(eg)]. The analogous complexes [ReO(L-3)(cat)] (H(2)cat = 1,2-dihydroxybenzene) and [ReO(L-3)(ox)] (H(2)ox = oxalic acid) could not be prepared by this method. [ReO(L-3)(cat)] was synthesized by the one-pot reaction of [ReOCl4-] with a twofold molar excess of HL3 and H(2)cat in ethanol, and [ReO(L-3)(ox)] was isolated from the reaction of [ReO(L-3)(eg)] and H(2)ox in acetonitrile. All complexes were characterized by various physical techniques, including IR and NMR. The X-ray crystal structure of [ReO(L-3)(cat). 1/2EtOH] was determined. Crystals are triclinic, (P) over bar, a = 8.920(2), b = 11.209(5), c = 11.735(5)Angstrom, alpha = 78.00(4), beta = 68.93(3), gamma = 86.49(3)degrees, Z = 2. The structure was solved by the Patterson method and refined by full-matrix least-squares procedures to R = 0.047 (R-w = 0.066) for 2321 reflections with F-0 > 3 sigma(F-0).