The photoelectron spectra of diazene, diazene-d2, and t r a n s-methyldiazene

Publisher Website
Google Scholar
Abstract
The photoelectron spectra of the transient species diazene, N2H2; diazene-d2, N2D2; and trans-methyldiazene, MeNNH have been recorded and interpreted. Four ionization potentials in the HeI energy range (21.2 eV) have been detected in the case of N2H2, where the orbital energies are found to follow the sequence n+, π, n−, and σ. N2H2 exhibits a highly structured photoelectron spectrum which has been fully resolved and analyzed in conjunction with its deutero analog. Several features of the spectrum are discussed, in particular the magnitude of the n+/n− separation, which is the largest yet observed, a comparison with N2F2 and the perfluoro effect, and the position of the π ionization. Our results also suggest that the 1700 Å band in the absorption spectrum of N2H2 is a n+→3p Rydberg transition. In addition, using the experimental Franck–Condon factors, we have deduced the geometry of the N2H2 and N2D2 ground state ions and compared the photoelectron spectra with the isoelectronic molecules B2H6, C2H4, CH2NH, and CH2O. The results for N2H2 and MeNNH are compared with the known data for MeNNMe, and the effect of increasing methylation on the orbital energies is discussed.