Abstract
There is a constant need for new and better methods to identify, characterize and separate different substances. Especially important are chiral molecules, since they play a crucial role in medical research and drug development. One recently developed method to identify enantiomeric excess is enantiomer specific microwave spectroscopy. To further optimize this technique we built a new re- action chamber containing a supersonic free jet source. In order to characterize the setup, we used resonance-enhanced multiphoton ionization spectroscopy of 1-indanol. The determined positions of the main transitions of three different 1-indanol conformers are in very good accordance with theoretical calculations, as well as with experimental data from the literature. Furthermore, valuable in- formation about 1-indanol has been gained, which will be useful in the future, because 1-indanol is a chiral molecule with a chromophore well suited for mi- crowave and ultraviolet spectroscopy experiments. The determined properties include the lifetime of the excited states of different 1-indanol conformers, which will indicate the obtainable resolution in high-resolution UV spectroscopy. In the experiments, the speed of the molecular beam, and thereby the ideal timings to conduct experiments for different carrier gases, were established. In addition, we characterized a newly designed slit valve based on a piezoelectric stack actuator, determining the optimal operation conditions, such as applied voltage, opening time, and backing pressure. Because of their unique beam shape, slit valves are highly interesting for spectroscopic applications. In an experiment, this beam shape can increase the number of molecules participating in the interaction and lower the angular velocity distribution, thereby leading to an improvement of the signal-to-noise ratio, and an improved spectral resolution.
