Cumulenic and heterocumulenic anions: potential interstellar species?

Authors

Stephen J. Blanksby, University of WollongongFollow
Andrew M. McAnoy, University of Adelaide
Suresh Dua, University of Adelaide
John H. Bowie, University of Adelaide

RIS ID

18890

Publication Details

Blanksby, S. J., McAnoy, A. M., Dua, S. & Bowie, J. H. (2001). Cumulenic and heterocumulenic anions: potential interstellar species?. Monthly Notices of the Royal Astronomical Society, 328 (1), 89-100.

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 & Bierbaumof 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_nH and C_n−1CH₂ and heterocumulenes C_nO (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.