Crystal and molecular structure of bis(tetraethylammonium) 1,2;2,3;3,1-tri-µ-hydrido-µ3,-oxo-1,1,1,2,2,2,3,3,3-enneacarbonyl-triangulo-trirhenate(2–)

Abstract

The title compound, [NEt₄]₂[Re₃H₃O(CO)₉], crystallizes in the orthorhombic space group Pnma with cell constants a= 15.05(2), b= 12.32(1). c= 18.35(2)Å, Z= 4. The structure has been determined by vector methods from single-crystal X-ray counter data and refined by block-diagonal least squares to a conventional R value of 0.032 for 1 147 independent reflections. The anion contains an equilateral triangle of metal atoms (mean Re–Re 2.968 Å) capped by a symmetric triply bridging oxo-ligand (mean Re–O 2.12 Å). The carbonyl groups are all terminally bonded, three for each rhenium atom (mean Re–C and C–O 1.88 and 1.18 Å). The overall idealized anion symmetry is C_3v. The carbonyl disposttion implies that the three hydrido-ligands lie in bridging positions on the Re₃ triangular edges.