Rotational spectra of CF⁺ and CF⁺: accurate rest frequencies and spectroscopic parameters

¹ Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, 40126 Bologna, Italy e-mail: [gabriele.cazzoli; cristina.puzzarini]@unibo.it
² Institut für Physikalische Chemie, Universität Mainz, 55099 Mainz, Germany e-mail: gauss@uni-mainz.de

Received: 3 August 2009
Accepted: 2 October 2009

Abstract

Context. The astrophysical relevance of the fluoromethylidynium ion and its importance for the interstellar chemistry of fluorine motivated the present laboratory spectroscopic investigation of both ¹²CF⁺ and the corresponding ¹³C-containing isotopologue, ¹³CF⁺.

Aims. This investigation has been carried out to provide accurate rest frequencies for future (radioastronomical) observations, to improve the accuracy of the values for the spectroscopic parameters available in the literature for CF⁺, and to provide them for the first time for ¹³CF⁺.

Methods. Rotational spectra of CF⁺ and ¹³CF⁺ were recorded in the millimeter- and submillimeter-wave frequency ranges. Their investigation was supplemented by high-level quantum-chemical computations using state-of-the-art coupled-cluster techniques.

Results. We report the most accurate ground-state rotational parameters available so far for CF⁺ and ¹³CF⁺.

Conclusions. The ground-state rotational parameters as well as the rest frequencies of ¹³CF⁺ will be useful for future observational purposes with the aim of improving the knowledge of fluorine interstellar chemistry.