ROTATIONALLY RESOLVED ELECTRONIC EXCITATION-SPECTRA OF THE ETHOXY (B)OVER-TILDE[-(X)OVER-TILDE TRANSITION

High-resolution electronic excitation spectra of the 0(0)0 and the 9(0 )2 bands of the near-UV electronic transition of the ethoxy radical ha ve been recorded. The ethoxy radical was produced in a free-jet expans ion by photodissociation of ethyl nitrite (C2H5ONO). Both spectra have a linewidth of about 400 MHz. A complete rotational analysis of the s pectrum indicates that the electronic transition of ethoxy is c-type ( perpendicular) and the ground-state spin-rotation splittings are fully resolved, while the excited state spin-rotation splittings are not re solved. The spin-rotational parameters are compared to the correspondi ng spin-rotational parameters of the closely related radicals, methoxy and vinoxy.