Reduction of unsaturated organic molecules by hydridocarbonyl cluster compounds of rhenium. Reaction of the anion [Re3(μ-H)4(CO)10]- with acetone: crystal structure of [NEt4][Re3(μ-H)3(μ-OCHMe2)(CO)10]

The reaction of the unsaturated anion [Re3(μ-H)4(CO)10]- in acetone affords the two saturated species [Re3(μ-H)3(μ-OCHMe2)(CO)10]- and [Re3(μ-H)3(μ3-OC-HMe2)(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 (NEt4)+ salt, has been investigated by X-ray analysis. The crystals are monoclinic, space group P21/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 Rw of 0.041 and 0.052, respectively. The anion contains an isosceles triangle of Re atoms, with two longer hydrogen-bridged ReRe 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 ReO(alkoxy) bonds is 2.153 Å. © 1988.