Ultra-low temperature hydrocarbon chemistry in liquid helium droplets

• Applicant: Professor Dr. Friedrich Huisken
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2008 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 58774912

The present project is devoted to the study of astrochemically relevant reactions at extremely low temperature (T = 0.37 K) as provided by liquid helium nanodroplets. The droplets are produced by supersonic expansion of helium gas through a cooled nozzle and directed as a “molecular beam” into a mass spectrometer detector. The reaction partners are deposited on or into the helium nanodroplets by letting the beam pass through individual pick-up cells or letting it cross with effusive beams. Several methods are applied to monitor the occurrence of reaction: Mass spectrometry, chemiluminescence detection, depletion technique, and laser spectroscopy. Information about the enthalpy of the reaction is obtained by measuring the size of the helium droplets before and after the reaction. To characterize the reaction products, mass spectrometry and laser spectroscopy will be used. The studies will focus on neu- tral-neutral reactions of astrochemical interest. Reactions between metal atoms Si, Al, Fe, and Mg with hydrocarbons will be studied. Hydrocarbon radicals will be produced by thermal dissociation of the precursor hydrocarbon gas. Reactions of these radicals with metal atoms and PAHs molecules will be studied. Also, attention will be given to the formation of large hydrocarbon molecules starting from the hydrocarbon radicals.

• DFG Programme: Research Grants