High-resolution IR spectroscopy of jet-cooled CF3CH2F

Abstract

The mid-IR spectrum of HFC-134a, CF₃CH₂F, entrained in a supersonic jet expansion has been measured at high and low resolution and the rotational structure of the C-type bands ν₁₄(1204 cm^–1) and ν₁₅(974 cm^–1) has been analysed along with the hot band ν₁₅+ν₁₈â†�ν₁₈. Rotational constants have been obtained and used to simulate the band structure, enabling the rotational temperature in the jet to be estimated at 65 K. In addition, low-resolution far-IR spectra of CF₃CH₂F in a room-temperature gas cell have been recorded and the vibrational fundamentals more completely assigned. These results are compared with previous experimental values and those predicted from molecular orbital calculations.