Spectrum of the CNN Molecule

We have recorded a laser excitation spectrum of the A31-I-X3E electronic band system oftheCNN radical in the gas phase, at a resolution of ca. 0.8cm-1. The rotationalbranch structure of the vibrational band near 419 nm has been simulated and molecular parameters are obtained. The results are compared with data from laser-inducedfluorescence spectra ofCNN trapped in a low-temperature matrix. A revised value for the spin-orbit parameter in the AII state is obtained and comparison is made with the values for related molecules. The possible detection ofCNN in astrophysical sources is considered and the general features of its rotational spectrum in the ground electronic state are described.