VIBRATION-ROTATION SPECTRA OF REACTIVE MOLECULES: INTERPLAY OF AB INITIO CALCULATIONS AND HIGH-RESOLUTION EXPERIMENTAL STUDIES

The significance of ab initio calculations at different levels for the determination of molecular parameters and the prediction of rotationally resolved infrared and microwave/millimeterwave spectra is outlined. The fruitful interplay of theoretical and experimental studies, mostly by high resolution Fourier Transform infrared spectroscopy, is demonstrated for the reactive and short-lived species FCCF and FCCCl. The predictive potential of ab initio calculations enabled the detection and characterization of the novel, hitherto unknown monohalogenophosphines PH₂X (X = F, Cl, Br, I).