Raman study of the pressure-induced phase transitions in the molecular donor–acceptor complex {Pt(dbdtc)2}C60

Raman spectra of the molecular donor–acceptor complex {Pt(dbdtc)2}C60 (C60 fullerene with platinum dibenzyldithiocarbamate) were measured as a function of pressure up to 8 GPa. In the low pressure regime (P < 0.5 GPa), the phonon modes related to the C60 molecule split and soften, indicating the formation of intercage covalent bonds. Additional splitting of Raman modes is observed at ∼2.5 GPa and is attributed to the formation of a polymeric network. The high-pressure phase remains stable upon pressure decrease, however at ∼0.5 GPa the material transforms to a new phase characterized by a Raman spectrum which is quite different from those of the known polymers of C60.