Pressure-induced phase transition of layer-structured host–guest hybrid based on C70 and p-But-calix[8]arene

Host–guest hybrid (HGH) consisting of p-But-calix[8]arene and fullerene C70 were fabricated with a facial solution deposition method. The as-prepared HGH samples are well periodic arranged in a layer structure, in which the interactions between the guest C70 and host p-Butcalix[8]arene molecules are van der Waals forces. High pressure Raman and UV–Vis absorption spectra studies on the HGH were recorded. Our results show that an orientational related phase transition and a one-dimensional (1D) polymerization of C70 molecules occur at about 2 and 7 GPa at room temperature, respectively. The band gap of the HGH translated synchronously with the change of structure upon compress. We suggest that the molecular confinement in such layer structure of the HGH restricts the polymerization of C70 molecules within a layer, which tunes the phase transition process of C70. This supplies a possible way to design fullerene-based functional materials at suitable conditions.