Preparation and structure of a non-carbide-stabilized octahedral rhenium cluster: [NEt4][Re6H7(CO)18]

The novel rhenium complex [NEt4][Re6H7(CO)18] has been isolated from the reaction between [Re4H4(CO)12] and NEt4BF4 in dichloromethane with or without acetone which facilitates the reaction. Its crystal structure has been determined: monoclinic, space group P21/n, a= 1 3.096(3), b= 19.408(4), c= 14.372(4)A, β= 90.65(2)°, Z= 4, R= 0.0392 and R′= 0.0375 from 6498 independent reflections. This shows that the anion is a non-carbide-stabilized octahedral rhenium cluster. The Re–Re distances are consistent with all hydrides occupying µ3-face-bridging positions.