The stretching wavenumber of a functional group exhibits a characteristic shift towards lower energies when serving as a hydrogen bond donor. This well-known effect constitutes an important tool for the study of such intermolecular interactions, and the observations are typically interpreted with the aid of quantum chemical calculations. However, the majority of these calculations are only feasible in a harmonic vibrational approximation, thus leaving a fundamental gap to the true experimental situation. It is therefore desirable to describe the spectroscopic shifts in terms of their harmonic and anharmonic contributions. To this end, the present thesis investigates a number of hydrogen-bonded model systems by means of vibrational spectroscopy in supersonic jets and cryogenic matrices. In conjunction with predictions from a wide range of quantum chemical calculations up to high levels of accuracy, the findings are able to provide a consistent picture for the desired decomposition of the observable spectroscopic effects.
