Trends in electron-vibration and electronic interactions in bis(dimethylamino) mixed-valence systems: A joint experimental and theoretical investigation

摘要

By using gas-phase ultraviolet photoelectron spectroscopy, vis/NIR spectroscopy, and electronic-structure calculations, we have investigated the electron-vibration and electronic interactions in a series of bis-dimethylamino mixed-valence systems: N,N,N',N'-tetramethyl-p-phenylenediamine, N,N,N',N'-tetramethyl-benzidine, and N,N,N',N'-tetramethyltolane-4,4'-diamine. Experiment and theory concur to indicate that the electron-vibration coupling in these systems is dominated by interactions with symmetric modes. The results reveal that the strength of both electronic and electron-vibration couplings decreases as the molecular bridge lengthens. The parameters derived for the present compounds have been compared to those of diarylamino-based structural analogs. This comparison underlines that the replacement of the methyl terminal groups with p-anisyl groups has a significant effect on the electronic and electron-vibrational interactions.