The possible interstellar anion CH2CN-: Spectroscopic constants, vibrational frequencies, and other considerations

Abstract

The A 1 B1 ← X̃ 1A′ excitation into the dipole-bound state of the cyanomethyl anion (CH 2CN?) has been hypothesized as the carrier for one diffuse interstellar band. However, this particular molecular system has not been detected in the interstellar medium even though the related cyanomethyl radical and the isoelectronic ketenimine molecule have been found. In this study, we are employing the use of proven quartic force fields and secondorder vibrational perturbation theory to compute accurate spectroscopic constants and fundamental vibrational frequencies for X̃ 1A ′ CH2CN ? in order to assist in laboratory studies and astronomical observations. © 2013. The American Astronomical Society. All rights reserved. Printed in the U.S.A.