Laser‐Induced‐FluorescenceSpectrum of the CNN Molecule

We have recorded a laser excitation spectrum of the A 3 Π –X 3 Σ − electronic band systemof the CNN radical in the gas phase, at a resolution of ca. 0.8 cm −1 . The rotational branchstructure of the vibrational band near 419 nm has been simulated and molecularparameters are obtained. The results are compared with data from laser-induced-fluorescencespectra of CNN trapped in a low-temperature matrix. A revised value forthe spin-orbit parameter in the A 3 Π state is obtained and comparison is made with thevalues for related molecules. The possible detection of CNN in astrophysical sources isconsidered and the general features of its rotational spectrum in the ground electronicstate are described.