INFRARED SPECTROSCOPIC STUDY OF THE STRUCTURAL TRANSITIONS OF C60BR24

Variable temperature infrared spectroscopy and differential scanning c alorimetry measurements show that C60Br24 undergoes two structural tra nsitions at 171 and 180 K with Delta H values of 0.87 and 3.94 kJ mol( -1) respectively. Only one transition is clearly visible in IR which i s manifested by the hardening of certain IR peaks and narrowing of the 1400 cm(-1) transition. The results support an orientational change a lthough ordering of the solvated bromine molecules could also be a rea son for the observed changes. (C) 1997 Elsevier Science B.V.