Anion metathesis in ionic silica nanoparticle networks

Metathesis reactions in acetone were performed on ionic silica networks based on imidazolium chloride bridging units. The salts investigated were NaBF4, KPF6 and LiN(SO2CF3)(2). XRD experiments and NMR analysis were used to follow the anion metathesis. For all compounds the thermal stability of the hybrid material was maintained after metathesis. SAXS experiments confirmed that the anion metathesis only very slightly affected the short-range order of the network. However, the yield of the metathesis reaction, depending on the length of the imidazolium based ligand, was evaluated by EDX analyses. The anion metathesis reaction provides a tailoring tool for hybrid material hydrophobicity.