Synthesis, isolation and spectroscopic characterization of Dawson polyoxotungstate-supported, organometallic complex, [{(C 6H 6)Ru}P 2W 15V 3O 62] 7−: The two positional isomers

Abstract

The Dawson polyoxotungstate (POM)-based, organometallic ruthenium(II) complex, [{(C 6H 6)Ru}P 2W 15V 3O 62] 7−, was synthesized as two materials, i.e. 1 · 2Bu 4NCl and 1 · 1Bu 4NCl ( 1 = (Bu 4N) 7[{(C 6H 6)Ru}P 2W 15V 3O 62]), which contained two positional isomers a and b as major or minor species. In isomer a with the overall C s symmetry, the (C 6H 6)Ru 2+ group was supported on one vanadium(V) octahedral site (two V–O–V bridging oxygens and one O V terminal oxygen) of the three edge-shared vanadium(V) octahedra (V 3 site, B-site) in the Dawson POM-support [1,2,3-P 2W 15V 3O 62] 9−, whereas in the other isomer b with the overall C 3 v symmetry, the (C 6H 6)Ru 2+ group was supported on the center of the V 3 site in the Dawson POM-support. Material 1 · 2Bu 4NCl was prepared by a stoichiometric reaction in CH 2Cl 2 at ambient temperature of the Dawson POM-support (Bu 4N) 9[1,2,3-P 2W 15V 3O 62] with the precursor [(C 6H 6)RuCl 2] 2, whereas material 1 · 1Bu 4NCl was prepared by a stoichiometric reaction in CH 3CN under refluxing conditions. The temperature-varied 31P NMR spectra revealed that b was thermodynamically more stable than a.