Éffets des interactions intermoléculaires par liaison hydrogène sur l'absorption et la luminescence des amines aromatiques en matrice vitreuse a 77 K

Abstract

The spectral properties of a series of aromatic amines (aniline, p-toluidine, dimethylaniline, N,N′- p-phenylenediamine (PPD), N,N,N′,N′-tetramethyl- p-phenylediamine (TMPD), diphenylamine, diphenylparaphenylenediamine in organic glasses at 77 K have been studied. The results obtained in two typical solvents, a non-polar one, methylcyclohexane, and a hydroxylic one, ethanol, indicate that solute—solvent and solute—solute H-bond associations play an important role in the phosphorescence intensity and lifetime. The various kinds of associations and their effect on the solute conformation are discussed. It is also shown that aniline, PPD and TMPD may be protonated in ethanol glasses, this is interpreted as being due to the enhancement of the solute—solvent H-bond in a rigid medium.