Structural changes of a fullerene-palladium (C60Pd3) coordination polymer under increased pressure conditions were monitored via in situ infrared and Raman spectroscopy. The body-centered cubic structure of the fullerene-based coordination polymer could be transferred to the amorphous (C60)n homofullerene polymeric phase under a mild pressure of ∼4.5 GPa. This phase was formed by C60Pd3 under considerably milder pressure conditions than C60 polymerization that required higher pressure. Analogous investigations performed with C60η2-Pd(PPh3)2 complex did not form the (C60)n homofullerene polymeric phase. The transformation of C60Pd3 to an amorphous homofullerene polymer phase was possibly because of the formation of metallic palladium nanocrystals and a local pressure increase, resulting in the formation of (C60)n. Additional theoretical calculations showed that pressure strongly influenced the bonding of fullerene moieties in the presence of palladium clusters. This effect was particularly significant in the case of C60 moiety linked through palladium atoms.
Zięba et al. (2026) studied this question.