Core excitation spectroscopy and the subsequent fragmentation processes of aromatic molecules.

摘要

To understand the effects of weak electron donors and the phenyl-phenyl interactions on the C 1s excitation spectra of substituted benzenes, vibrationally resolved spectra of benzene, toluene, ethylbenzene and 1,3-diphenylpropane have been recorded.;By comparison of the spectra of ethylbenzene, diphenylpropane and polystyrene, it is concluded that there are no phenyl-phenyl interactions in diphenylpropane, but such interactions may exist in polystyrene. Furthermore, it was found that ethylbenzene is a good model for the study of polystyrene.;Spectroscopic simulations of toluene and ethylbenzene, based on ab initio calculations, indicate that the differences between the pi* resonances of toluene and ethylbenzene and that of benzene can be attributed primarily to chemical shifts.;The study of the photofragmentation processes of the core excited molecules indicates that there are significant recombinations occurring in the photoionisation processes and that the fragmentation is not localized in diphenylpropane.