Solid-state and solution structure of a hypervalent AX 5 compound: Sb(C6F5)5

Eliminating restraints: A trigonal-bipyramidal structure has been found to be the energetically favored geometry of the hypervalent AX 5 molecule Sb(C 6F 5) 5 in the solid state and also in fluid solution, where molecules move freely and no crystal packing effects operate (see picture).This work was supported by the Spanish MICINN (DGPTC)/FEDER (project number CTQ2008-06669-C02-01/BQU) and the Gobierno de Aragón (Grupo Consolidado E21: Química Inorgánica y de los Compuestos Organometálicos).Peer Reviewe