Eur. Phys. J. D (2013) 67: 230
https://doi.org/10.1140/epjd/e2013-40422-9

Regular Article

Resonant electron attachment to polar aromatic molecules: consequences for their chemistry in the interstellar medium^*

¹ Department of Chemistry and CISM, The University of Rome ‘Sapienza’, P.le Aldo Moro 5, 00185 Rome, Italy
² CNR-ISMN, P.le Aldo Moro 5, 00185 Rome, Italy

^b e-mail: francesco.gianturco@uniromal.it

Received: 16 July 2013
Received in final form: 31 August 2013
Published online: 15 November 2013

Abstract

In this paper we present and discuss the results obtained from ab-initio quantum scattering calculations of the response from neutral aromatic species like C₆H₅ (phenyl) and C₆H₄ (benzyne, ortho isomer) to low-energy electron collisions. Our main purpose is to investigate the possible mechanisms that can lead to the final formation of their stable negative ions under astrophysical conditions, by linking low-lying metastable anionic states to bound anionic states. Quantum chemical calculations were also employed to confirm the features of the metastable resonant states found by the scattering calculations, while the role of the permanent dipole moments of both systems on the scattering behaviour for near-threshold electrons is also analysed in some detail. The possible energy redistribution paths for stabilizing both anionic species under ISM conditions are discussed in the conclusions.