Reduction of unsaturated organic molecules by hydridocarbonyl cluster compounds of rhenium. Reaction of the anion [Re 3(μ-H) 4(CO) 10] − with acetone: crystal structure of [NEt 4][Re 3(μ-H) 3(μ-OCHMe 2)(CO) 10

Abstract

The reaction of the unsaturated anion [Re 3(μ-H) 4(CO) 10] − in acetone affords the two saturated species [Re 3(μ-H) 3(μ-OCHMe 2)(CO) 10] − and [Re 3(μ-H) 3(μ 3-OC-HMe 2)(CO) 9] − as a result of the attack of a hydride ligand of the parent anion on the ketonic carbon atom to give an isopropylate group. The structure of the former anion, as its (NEt 4) + salt, has been investigated by X-ray analysis. The crystals are monoclinic, space group P2 1/ c, with a 8.767(4), b 25.913(6), c 13.175(4) Å, β 91.80(4)° and Z = 4. The refinements performed by full-matrix least-squares methods, on the basis of 2847 independent significant reflections, with I > 3σ( I), gave final values of the conventional agreement indices R and R w of 0.041 and 0.052, respectively. The anion contains an isosceles triangle of Re atoms, with two longer hydrogen-bridged ReRe edges (mean 3.211 Å), and one shorter edge (2.930(1) Å) doubly bridged by a hydride and the isopropylate ligand. The mean value of the ReO(alkoxy) bonds is 2.153 Å.