C2 AND CN FORMATION BY OPTICAL-PUMPING OF CO-AR AND CO-N2-AR MIXTURES AT ROOM-TEMPERATURE

A continuous wave carbon monoxide laser is used to excite the vibrational mode of CO in CO/Ar and CO/N2/Ar mixtures flowing through a gas absorption cell. High steady-state excitation of the CO vibrational mode (0.3 eV/molecule) is achieved, while a translational-rotational temperature near 300 K is maintained by the steady flow of cold gas into the cell. These non-equilibrium conditions result in extreme vibration-vibration pumping, population high-lying vibrational quantum levels (to V = 42) of CO. N2 can also be pumped by vibrational energy transfer from CO. Under these conditions, C2 and CN molecules are formed, and are observed to fluoresce on various electronic band transitions, notably C2 Swan (A 3Πg-X 3Πu) and CN violet (B 2Σ+-X2Σ+). © 1979.