High-resolution infrared spectrum of cyanogen

► High resolution infrared spectrum of 12C14N (cyanogen) from 500 cm−1 to 4900 cm−1. ► First observation of combination bands involving both degenerate vibrational levels ν4 and ν5. ► Combines the approximate Be values of three isotopomers to obtain equilibrium bond lengths. ► Vibrational and rotational term value constants are given and compared with those for 13C214N2 and 12C215N2.