Synthesis and high pressure studies of white luminescence host–guest complex nanocrystals based on C₆₀ and p-But-calix[8]arene

Host–guest structured nanocrystals consisting of p-But-calix[8]arene and fullerene C₆₀ were fabricated with the facial solution deposition method. The as-prepared host–guest complex nanocrystals are well crystallized in a tetragonal structure, in which the guest C₆₀ and host p-But-calix[8]arene molecules interact with each other via the van der Waals force. The host–guest crystal has a wider band gap compared to that of C₆₀ crystals. The luminescence range of the host–guest structured nanocrystals was widely extended, and its photoluminescence (PL) intensity was highly enhanced by one order of magnitude. High pressure studies on such host–guest nanocrystals were carried out using the diamond anvil cell technique with the associated spectroscopic measurements. Raman and PL spectra show a phase transition occurred on the samples owing to the deformation of fullerene molecules. A PL behavior change was also observed synchronously with the phase transition. The host–guest structure strongly influences the structure and optical behaviors of C₆₀ under pressure. (paper)