Derivatives of Monogermane: Part I. The Vibration–rotation Spectra of Germyl Fluoride and Bromide

The vibration–rotation infrared absorption spectra of germyl fluoride and bromide have been observed. All of the fundamentals in GeH 3 F were located, and the rotational structure of the E-type bands were resolved and analyzed. The low-frequency band, ν 3 (a 1 ), in GeH 3 Br was not observed but an estimate of its position was made from the frequencies of the combination band ν 3 + ν 6 and of ν 6 . The rotational constant A″ and the Coriolis constants ζ 4 , ζ 5 , and ζ 6 were calculated for both molecules, and agreement with microwave A″ values was satisfactory. Thermodynamic functions based upon a rigid-rotator, harmonic-oscillator model have been evaluated for germyl fluoride and bromide.