LASER EXCITATION AND EMISSION-SPECTROSCOPY OF THE METHOXY RADICAL IN A SUPERSONIC JET

Laser-induced excitation and wavelength-resolved emission spectra of the methoxy (CH3O) radical have been obtained in a supersonic jet environment. Fluorescence in the near ultraviolet from several vibronic bands belonging to the (A) over tilde(2)A(1)-(X) over tilde(2)E electronic system of CH3O has been dispersed by a 0.6 m monochromator with a resolution of 0.3 nm. A complete set of vibrational frequencies with all assignments for the (X) over tilde(2)E state of CH3O has been obtained. To the best of our knowledge, the dispersed spectra of CH3O for the 2(0)(2) and 2(0)(1)3(0)(1) bands are presented here for the first time. The vibrational constants determined by a least-squares fit for the nu(3) mode are omega(e)'' = 1071 cm(-1) and omega(e)''chi(e)'' = 8.4 cm(-1). For the Jahn-Teller active nu(6) mode, the vibrational and anharmonic constants omega(e)'' = 786 cm(-1) and omega(e)''chi(e)'' = 55 cm(-1), respectively, have been obtained for the first time.