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 ) (p K 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.