The Possible Interstellar Anion CH2CN-: Spectroscopic Constants, Vibrational Frequencies, and Other Considerations

TL;DR

This paper calculates precise spectroscopic data for the interstellar anion CH2CN- to aid in its potential detection in space, using advanced computational methods to support laboratory and astronomical research.

Contribution

It provides the first detailed spectroscopic constants and vibrational frequencies for CH2CN- using quartic force fields and vibrational perturbation theory.

Findings

Computed accurate spectroscopic constants for CH2CN-

Predicted fundamental vibrational frequencies for laboratory identification

Supported future astronomical searches for the anion

Abstract

It is hypothesized that the A ^1B_1 <- X ^1A' excitation into the dipole-bound state of the cyanomethyl anion (CH2CN-) is proposed 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 second-order vibrational perturbation theory to compute accurate spectroscopic constants and fundamental vibrational frequencies for ^1A' CH2CN- in order to assist in laboratory studies and astronomical observations.