Synthesis and Redox-Induced Structural Isomerization of the Pentagonal Bipyramidal Complexes [W(CN)5(CO)2]3- and [W(CN)5(CO)2]2-

(Figure Presented) Mixed company: The use of a mixed carbonyl/cyanide ligand set enables stabilization of two new heptacoordinate complexes: [W(CN)5(CO)2]3- and [W(CN)5(CO) 2]2-. In the trianionic complex the two carbonyl ligands occupy the axial positions. Remarkably, one-electron oxidation causes loss of this axial symmetry, as shown by X-ray crystallography (see picture, orange W, gray C, blue N, red O), IR, and EPR spectroscopy. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.