A study of the higher electronic transitions of selenoformaldehyde, CH2Se

The pi --> pi* and n --> 5s absorption spectra of selenoformaldehyde, CH2Se and CD2Se, are reported. Both spectra are diffuse. The pi --> pi* transiti on extends from 243 to 210 nm with an extensive Franck-Condon profile and i ntensity maximum estimated at 230 nm. The Rydberg pi --> 5s transition is s uperimposed on the n --> pi* system. While still diffuse, the system is les s extensive and shows an intensity maximum at 235 nm. The corresponding Ryd berg transition of the deuterated species is blue shifted by 140 cm(-1). (C ) 1999 Academic Press.