Speaker
Description
The combination of mass spectrometry (MS) and infrared (IR) spectroscopy is a powerful tool to elucidate the structure of isolated ions in the unique clean-room environment of the gas-phase. To avoid line broadening due to thermal contributions during the measurement, cryogenic ion spectroscopy can be employed. In our experimental setup we use helium nanodroplets as a matrix to cool ions to their extremely low equilibrium temperature of 0.4 K. This experimental approach can be utilized to capture both cationic and anionic molecules ranging in size from tens of Da to several kDa and subsequently probe their structure using infrared radiation produced by the FHI-FEL. In the past, we used this method for the structural analysis of biomolecules such as peptides and proteins as well as complex oligosaccharides. Using a different MS/IR spectroscopy method at room temperature, the analysis of ionic molybdenum oxide clusters failed to unambiguously assign the molecular structure, which is mainly attributed to thermal peak broadening. This system will provide an excellent benchmark to evaluate our cryogenic spectroscopy towards the analysis of ionic metal clusters.
