Infrared spectroscopic study of the structural transitions of C<inf>60</inf>Br<inf>24</inf>

Variable temperature infrared spectroscopy and differential scanning calorimetry measurements show that C60Br24 undergoes two structural transitions at 171 and 180 K with ΔH values of 0.87 and 3.94 kJ mol-1 respectively. Only one transition is clearly visible in IR which is manifested by the hardening of certain IR peaks and narrowing of the 1400 cm-1 transition. The results support an orientational change although ordering of the solvated bromine molecules could also be a reason for the observed changes.