Effect of pressure and temperature on the intermolecular mean square torque in liquid CS2 and CCl4

Abstract

The effects of temperature and externally applied pressure on the intermolecular mean square torque 〈O(V)²〉 in liquid CS₂ and CCl₄ are estimated using the induced absorption bands of these liquids at high microwave and far infrared frequencies (2–300cm^–1). For the stick-like CS₂ molecule it is found that 〈O(V)²〉 is considerably increased by an external pressure of 11.6 kbar. For this molecule, 〈O(V)²〉 increases with T in the range 232–315 K. However, the situation is different for the spherical top CCl₄, where a considerable increase in free volume allows 〈O(V)²〉 to decrease slightly from 296 to 343 K, a few degrees below the boiling point at 1 bar.