Electroactive sulfur-rich materials obtained via inverse vulcanization of a diallylsilyl-functionalized ferrocene

Reaction of elemental sulfur with 1,1 '-bis(dimethylallylsilyl)ferrocene (1) in 50 : 50 or 70 : 30 wt% at 130 degrees C results in new polymeric materials as a consequence of an inverse vulcanization process. Through this procedure, allylsilyl-functionalized ferrocene moieties are integrated into a solid matrix structured by the formation of covalent C-S bonds between sulfur atom chains and organometallic co-monomers. The structure and composition of the amorphous materials obtained have been assessed by elemental analysis, TXRF, ATR-IR, solid-state NMR, XPS and SEM. Remarkably, the electrochemical activity of ferrocene fragments is preserved when incorporated into the polysulfide material. Consequently, 1 is the first silicon- and ferrocene-containing molecule being used as a co-monomer to develop redox-responsive polysulfide materials. Furthermore, the interaction of sulfur atoms with Cd(ii) or Hg(ii) metal centers, present in aqueous solutions, results in the modulation of the electrochemical signal of ferrocene moieties. Therefore, this work presents the synergistic combination of polysulfide chains and ferrocene fragments resulting in electrochemical recognition of harmful metal centers commonly present in polluted hydric resources.