High-resolution infrared action spectroscopy of the fundamental vibrational band of CN+

TL;DR

This study reports the first high-resolution infrared spectroscopy of the fundamental vibrational band of CN+ ions, providing new spectroscopic parameters for two isotopologues using cryogenic ion trap action spectroscopy.

Contribution

It introduces a novel application of cryogenic ion trap action spectroscopy to observe rotational-vibrational transitions of CN+ ions for the first time.

Findings

Measured vibrational band origins at 2000.7587 and 1970.321 cm$^{-1}$.

Provided spectroscopic parameters for both isotopologues.

Developed an isotope-independent fit combining new and literature data.

Abstract

Rotational-vibrational transitions of the fundamental vibrational modes of the $^{12}$C$^{14}$N$^+$ and $^{12}$C$^{15}$N$^+$ cations have been observed for the first time using a cryogenic ion trap apparatus with an action spectroscopy scheme. The lines P(3) to R(3) of $^{12}$C$^{14}$N$^+$ and R(1) to R(3) of $^{12}$C$^{15}$N$^+$ have been measured, limited by the trap temperature of approximately 4 K and the restricted tuning range of the infrared laser. Spectroscopic parameters are presented for both isotopologues, with band origins at 2000.7587(1) and 1970.321(1) cm$^{-1}$, respectively, as well as an isotope independent fit combining the new and the literature data.