Abstract book - Prof. Per Jensen, Ph.D. - Bergische Universität ...

82 Poster session, D35Dissociative electron attachment in molecules from alkynes familyRadmila Janečková 1 , Olivier May 1 , Juraj Fedor 11 Department of Chemistry, Switzerland, radmila.janeckova@unifr.chThe absolute cross sections for formation of ions by dissociative electron attachment(DEA) to methylacetylene (HCCCH 3 ), to deuterated methylacetylene (HCCCD 3 ) and aswell dimethylacetylene (CH 3 CCCH 3 ) have been measured by spectrometer withtrochoidal electron monochromator combined with quantitative time-of-flight massspectrometer 1 .This work has been motivated by role of these molecules in interstellar media and upperplanetary atmospheres 2,3 , as well as by previous studies of acetylene in our laboratory 1,4 .The main product from low-energy dissociative electron attachment to methylacetyleneand deuterated methylacetylene is the (M-1) - anion corresponding to abstraction of onehydrogen atom. The (M-1) - peak cross section is lower than that in acetylene. Asexpected, C 2 H - ions have not been formed, which confirms that the C-CH 3 bond is notcleaved by low-energy electrons. This has been verified in DEA to dimethylacetylene,where no fragments except H - have been detected. Possible origins of this effect arediscussed.Janeckova R.May O.Fedor J.Fig. 1: The main product from DEA to methylacetylene and deuterated methylacetylene.References[1] O. May, J. Fedor, M. Allan, Phys. Rev. A, 80, 012706, 2009[2] S. Gupta, E. Ochiai, C. Ponnamperuma, Nature (London), 293, 725, 1981[3] D. E. Shemansky, A. I. F. Stewart, R. A. West et al, Science 308, 978, 2005[4] O. May, J. Fedor, B. C. Ibanescu and M. Allan, Phys. Rev. A, 77, 040701, 2008