Abstract:
Raman spectroscopy has been used to investigate the monoclinic crystal f rotator f melt phase transitions
in n-C34H70, for both real-time heating and cooling runs. Changes in band intensity and frequency in the CH2
bending, CH2 twisting, skeletal C-C stretching, and CH3 rocking regions revealed both transitions, particularly
when using band components related to gauche bonds. In the room temperature infrared spectrum, the CH2
rocking-twisting and CH2 wagging progressions were observed and indexed for n-C34H70 and a 2:1 (w/w)
mixture of C34H70 and C36D74. This led to best estimates for the all-trans crystal core in both cases of 33 to
34 carbon atoms, indicating that the core corresponds to almost the whole of the C34H70 molecule.
