Schwingungsaufgelöste Untersuchungen an Azabenzolen mittels Mass-Analyzed-Threshold-Ionization Spektroskopie
Mass-Analyzed-Threshold-Ionization (MATI) spectroscopy is a powerful tool for the examination of ionic states. In combination with Resonance-Enhanced-Multi-Photon-Ionization it is possible to get information about the ionic ground state and the selected intermediate state in the same spectrum. In this work vibrational resolved spectra of the azabenzenes pyridine, pyrimidine and pyrazine in the ionic ground state have been measured. To add further evidence to the observations quantum chemical calculations have been conducted. For the simplest azabenzene pyridine no vibrational resolved spectra of the ionic ground state where available till now. It could be shown that contrary to prior findings Pyridine undergoes a geometrical distortion from a planar to a non planar form upon activating the first excited state. This distortion leads to a symmetry reduction in the first excited state. For pyrimidine and pyrazine it could be shown that they retain their planar form in the first excited state as well as in the ionic ground state.