High-resolution infrared spectrum of the v₃ and v₆ bands of HCF₃ and of their hot bands

Abstract

The infrared spectrum of fluoroform has been recorded between 480 and 730 cm^-1 at a resolution of 0·03 cm^-1. The v ₆ perpendicular band at 507·8228 (6) cm^-1, heavily perturbed by an l(2,2) type rotational resonance, has been analysed in the P and R as well as in the Q branches. The v ₃ parallel band at 700·1009 (6) cm^-1 has also yielded molecular constants including C″ - C′. Each of these bands is accompanied by hot bands among which v ₃ + v ₆ - v ₆ and 2v ₆ - v ₆ deserved special attention since both the upper and lower states of these transitions are perturbed.