The infrared laser spectrum of the CN radical in its ground state

Abstract
Ten vibration–rotation transitions in the fundamental band of the CN radical in its ground 2J+ electronic state have been measured in absorption using a tunable infrared diode laser. The observed frequencies are in good agreement with the values derived from optical emission spectroscopy. Splittings arising from electron spin–rotational fine structure are resolved in some of the transitions and agree with values calculated from the spin–rotation constants measured in laboratory microwave studies.