Structure of the triaquatricarbonylrhenium(I) cation and its conjugate base

The crystal structure of the Re(CO)(3)(H2O)(3)(+) cation has been determined from crystals obtained by evaporation of an aqueous solution of [Re(CO)(3)(H2O)(3)]Br. The bromide ion is incorporated in the Re-2(CO)(9)(mu(3)-Br)(3)(-) anion. A second structure was obtained by removal of bromide as AgBr and precipitation of the Re(CO)(3)(H2O)(3)(+) cation with PF6-, In the latter structure the conjugate base, Re(CO)(3)(OH)(H2O)(2) is co-crystallized in the structure. Each structure along with the previously known cubane [Re(CO)(3)(mu(3)-OH)](4)-4H(2)O was obtained multiple times during crystallization studies. The use of other anions to generate crystalline products was unsuccessful. (C) Wiley-VCH Verlag GmbH & Co.