• Meier, S.C.; Holz, A.; Kulenkampff, J.; Schmidt, A.; Kratzert, D.; Himmel, D.; Schmitz, D.; Scheidt, E.; Scherer, W.; Bülow, C.; Timm, M.; Lindblad, R.; Akin, S.; Zamudio-Bayer, V.; von Issendorff, B.; Duncan, M.; Lau, J.T.; Krossing, I.: Access to the Bis-benzene Cobalt(I) Sandwich Cation and its Derivatives: Synthons for a "Naked" Cobalt(I) Source? Angewandte Chemie - International Edition 57 (2018), p. 9310-9314


The synthesis and structural characterization of the hitherto unknown parent Co(bz)2+ (bz=benzene) complex and several of its derivatives are described. Their synthesis starts either from a CoCO5+ salt, or directly from Co2(CO)8 and a Ag+ salt. Stability and solubility of these complexes was achieved by using the weakly coordinating anions (WCAs) [Al(ORF)4]-; and [F{Al(ORF)3}2]- {RF=C(CF3)3} and the solvent ortho-difluorobenzene (o-DFB). The magnetic properties of Co(bz)2+ were measured and compared in the condensed and gas phases. The weakly bound Co(o-dfb)2+ salts are of particular interest for the preparation of further CoI salts, for example, the structurally characterized low-coordinate 12 valence electron Co(PtBu3)2+ and Co(NHC)2+ salts.