Gas Phase Biomolecules: Structural Motifs Revealed by Ionization Loss Stimulated Raman Spectroscopy

In recent years much effort has been devoted to the measurement and modelling of three dimensional structures of biologically relevant molecules Previous studies have shown that one can differentiate between structures of the same molecule by combining novel laser spectroscopies employing double resonance or hole burning techniques with quantum computations These methods allow monitoring of electronic and vibrational spectra in limited ranges Full vibrational spectra that include low frequency modes constitute a real challenge for experiment and theory but if accessible could provide important new information on inter and intra molecular vibrations hydrogen bonding and structural details Our group developed and employs ionization loss stimulated Raman spectroscopy ILSRS which allows to monitor a significantly broader spectral range compared to other methods Up to now this method was applied to a variety of neurotransmitters NTs and here to a fluorine substituted compound The resulting distinctive ILSR spectra compared to the results of quantum calculations provided the possibility to distinguish between three different structures in the molecular beam and to gain insight into the stabilizing interactions in these structures