OBSERVATION OF CHARGE-TRANSFER COMPLEX ORIENTATIONAL PHASE-TRANSITIONS BY MEANS OF FOURIER-TRANSFORM INFRARED-SPECTROSCOPY

Fourier transform infrared spectroscopy was used to monitor the approximately 200 K order-disorder phase transition of anthracene-h//1//0: tetracyanobenzene and anthracene-d//1//0: tetracyanobenzene charge transfer complexes. It is shown that the technique is sufficiently sensitive to monitor the temperature of transition and to study the transition via the infrared active internal vibrational modes.