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

Laser-induced excitation and wavelength-resolved emission spectra of t he methoxy (CH3O) radical have been obtained in a supersonic jet envir onment. Fluorescence in the near ultraviolet from several vibronic ban ds belonging to the (A) over tilde(2)A(1)-(X) over tilde(2)E electroni c system of CH3O has been dispersed by a 0.6 m monochromator with a re solution 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 obtaine d. 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 tim e. 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 anh armonic constants omega(e)'' = 786 cm(-1) and omega(e)''chi(e)'' = 55 cm(-1), respectively, have been obtained for the first time.