Amine-oxide-mediated reactions of Re2(CO)10 with phenol and aliphatic alcohols: The formation of Re3(CO)14(μ-H) and a hydroxo-methoxo trirhenium aggregate [Me3NH]+[Re3(CO)9(μ-OH)2(μ-OMe)(μ3-OMe)]-

Abstract

Oxidative decarbonylation of Re2(CO)10 by Me3NO in a mixture of THF and phenol resulted in Re3(CO)14(μ-H), 1, and [Me3NH]+[Re2(CO)6(μ-OPh)3]-, 2, in 30 and 17% yields respectively. In the analogous reaction in THF-MeOH mixture, a trinuclear complex, [Me3NH]+[Re3(CO)9(μ-OH)2(μ-OMe)(μ3-OMe)]-, 3, was isolated instead. The structure of 3 was determined by single-crystal X-ray diffraction analysis: orthorhombic, space group Ama2, a = 14.022(2), b = 18.003(5), c = 9.601(2) Å, final R = 0.031 for 958 reflections. The anion contains a Re3 triangle edge-bridged by one methoxy and two hydroxy ligands and capped by a methoxy group. No formal Re-Re bond (Re ⋯ Re 3.423 and 3.439 Å) is envisaged. Possible mechanisms for the formation of 1, 2 and 3 are proposed. © 1997 Elsevier Science S.A.