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

6 pags., 3 figs., 3 tabs.Rotational-vibrational transitions of the fundamental vibrational modes of the CN and CN 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 CN and R(1) to R(3) of CN 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, respectively, as well as an isotope independent fit combining the new and the literature data.This work (including the research visit of JLD in Köln) has been supported by the Deutsche Forschungsgemeinschaft (DFG) via SFB 956 project B2 (project ID 18401886) and DFG SCHL 341/15-1 (“Cologne Center for Terahertz Spectroscopy”). JLD acknowledges partial support from the Spanish AEI through grant FIS2016-77726-C3-1-P and from the European Research Council through grant agreement ERC-2013-SyG-610256-NANOCOSMOS