The different reactivity of 2-aminopyridines and 2-pyridone with [Ru3(CO)12]. X-Ray crystal structure of [Ru3(µ-H)(µ3-anpy)(CO)9](hanpy = 2-anilinopyridine)

Abstract

The complex [Ru₃(CO)₁₂] reacts with 2-aminopyridines [2-aminopyridine, 2-amino-4-methylpyridine, -5-methylpyridine, and -6-methylpyridine, 2-(methylamino)pyridine, and 2-anilinopyridine] to give hydrido trinuclear clusters of the type [Ru₃(µ-H)(µ₃-L)(CO)₉](1)–(6)(L = a 2-aminopyridinate-type ligand). Although the presence of substituents on the pyridine ring or on the aminic nitrogen has no influence on the reactivity of the ligands towards [Ru₃(CO)₁₂], it affects the fluxionality of the complexes they form. The solid-state structure of [Ru₃(µ-H)(µ₃-anpy)(CO)₉](6)(Hanpy = 2-anilinopyridine) has been determined by X-ray diffraction methods: monoclinic, space group P2₁/n, Z= 4, a= 12.705(1), b= 10.621 (2), c= 18.427(2)Å, and β= 107.349(7)°. The structure was solved by direct and Fourier methods and refined by full-matrix least squares to R= 0.019, R′= 0.021, for 3 621 observed reflections. The reaction of [Ru₃(CO)₁₂] with 2-(dimethylamino)pyridine (dmapy) gives [Ru₃(µ-dmapy)(µ-CO)₃(CO)₇]. However, with 2-pyridone (HOpy) the polymer [{Ru₂(µ-Opy)₂(CO)₄}_n](8) or the dimer [Ru₂(µ-Opy)₂(CO)₄(HOpy)₂](13) are formed depending on the ratio of the reactants. The reactivity of the polymer (8) with neutral ligands to give the binuclear ruthenium(I) dimers [Ru₂(µ-Opy)₂(CO)₄L₂][L = CO, (9); MeCN, (10); PPh₃, (11); P(OPh)₃, (12); or HOpy, (13)] is also reported.