Cumulenic and heterocumulenic anions: potential interstellar species? |
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| Authors: | Stephen J Blanksby rew M McAnoy Suresh Dua John H Bowie |
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| Institution: | Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA;Department of Chemistry, University of Adelaide, SA 5005, Australia |
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| Abstract: | A recent theoretical investigation by Terzieva & Herbst of linear carbon chains, C n where n ≥ 6, in the interstellar medium has shown that these species can undergo efficient radiative association to form the corresponding anions. An experimental study by Barckholtz, Snow & Bierbaum of these anions has demonstrated that they do not react efficiently with molecular hydrogen, leading to the possibility of detectable abundances of cumulene-type anions in dense interstellar and circumstellar environments. Here we present a series of electronic structure calculations which examine possible anionic candidates for detection in these media, namely the anion analogues of the previously identified interstellar cumulenes C n H and C n ?1CH2 and heterocumulenes C n O (where n = 2–10). The extraordinary electron affinities calculated for these molecules suggest that efficient radiative electron attachment could occur, and the large dipole moments of these simple (generally) linear molecules point to the possibility of detection by radio astronomy. |
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| Keywords: | molecular processes ISM: abundances – ISM: lines and bands – ISM: molecules – infrared: ISM – radio lines: ISM |
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