Reactions of cyano ions – from the lab to ionospheres
Molecular Physics seminar
Monday 21 September 2015
to 11:00 at
Wolf Geppert (Chemical Physics)
Ions containing cyano groups have been detected in a multitude of environments. In the interstellar medium, the ion C₃N¯ has been unambiguously identified, whereas a tentative detection of C₅N¯ still awaits confirmation by lab spectroscopy. The Ion and Neutral Mass spectrometer (INMS) on board the Cassini spacecraft has recorded a multitude of protonated nitriles in the ionosphere of the Kronian satellite Titan, and many of their abundances by far exceeded the numbers predicted by earlier models. Furthermore, the Cassini Plasma spectrometer observed the anions CN¯, C₃N¯, and possibly C₅N¯ in Titan’s atmosphere. In addition, heavy cations and anions (with masses up to 10 000 amu) have been detected in this environment. The question arises how these species are formed and which role processes induced by smaller ions are involved in the build-up of this large species. It is therefore vital to investigate the reactions of the most prominent cyano cations in the interstellar medium and planetary atmospheres.
Whereas photodetachment reactions of cyano ions were investigated using ion traps, guided beam measurements have been performed to investigate ion-neutral reactions of these species. The talk will give an overview of the recent experimental results on reactions of cyano ions and their products and discuss implications of these findings on interstellar and ionospheric chemistry.