A decacationic ferrocene-based metallostar

Decacationic metallostars have been prepared by the reaction of permercurated ferrocene FeC(10)(HgO(2)CCF(3))(10) with superacidic (C(5)F(5)NH)(SbF(6)) (pK(a) = −11 estimated in H(2)O) in multigram scale. In the resulting compound, [FeC(10)Hg(10)(NC(5)F(5))(n)][SbF(6)](10), the labile pentafluoropyridine ligands are readily displaced by acetonitrile (MeCN) or tetrahydrothiophene (THT). In the X-ray structure of [FeC(10)Hg(10)(THT)(10)][SbF(6)](10)·24 MeCN no cation–anion contacts between mercury and fluorine were observed. Moreover, cyclic voltammetry measurements of [FeC(10)(Hg(MeCN))(10)](10+) and [FeC(10)(Hg(THT))(10)](10+) revealed a (quasi)reversible one-electron oxidation of Fe(ii) to Fe(iii). From the reaction of [FeC(10)(Hg(MeCN))(10)](10+) with MoF(6) as oxidant the ferrocenium cation [FeC(10)(Hg(MeCN))(10)](11+) was obtained and characterized via single crystal XRD. These electrophilic metallostars are promising potential building blocks for the synthesis of dendritic architectures containing a robust, tenfold functionalized ferrocene core.