ELECTRON-AFFINITY AND DISSOCIATIVE ELECTRON-ATTACHMENT IN SATURATED DIALKYL GROUP-16 DERIVATIVES

Gas-phase temporary negative-ion formation in the series R2X (X = O, S, Se and Te; R = C2H5 or CH3) has been studied using electron-transmission spectroscopy in the 0-5 eV energy range. The ground anion state, associated with electron capture into the lowest-lying sigma* orbitals of prevailing heteroatom character, steadily decreases in energy with increasing heteroatom size. The spectra of related derivatives containing S-S and Se-Se bonds display additional resonances ascribed to empty sigma* orbitals of mainly heteroatom-heteroatom character. The dissociative attachment spectra of the compounds display abundant fragmentation yields below 1 eV electron energy.