A decacationic ferrocene-based metallostar.

Decacationic metallostars have been prepared by the reaction of permercurated ferrocene FeC10(HgO2CCF3)10 with superacidic (C5F5NH)(SbF6) (pK a = -11 estimated in H2O) in multigram scale. In the resulting compound, [FeC10Hg10(NC5F5) n ][SbF6]10, the labile pentafluoropyridine ligands are readily displaced by acetonitrile (MeCN) or tetrahydrothiophene (THT). In the X-ray structure of [FeC10Hg10(THT)10][SbF6]10·24 MeCN no cation-anion contacts between mercury and fluorine were observed. Moreover, cyclic voltammetry measurements of [FeC10(Hg(MeCN))10]10+ and [FeC10(Hg(THT))10]10+ revealed a (quasi)reversible one-electron oxidation of Fe(ii) to Fe(iii). From the reaction of [FeC10(Hg(MeCN))10]10+ with MoF6 as oxidant the ferrocenium cation [FeC10(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.