INTRAMOLECULAR CHARGE-TRANSFER INDUCED BY SOLVENT INTERACTION

The effect of solvation on the appearance of a red shifted Twisted Intramolecular Charged Transfer emission is reviewed. Comparison between condensed phase and small cluster red fluorescence is discussed in the particular case of methyl 4-N,N-dimethylaminobenzoate (DMABME). Using a supersonic expansion DMABME-(H2O)(n) clusters are studied by monitoring at the same time mass spectra and dispersed fluorescence spectra as well as by lifetime measurements. For DMABME-(H2O)(n) clusters, a clear red shifted fluorescence is observed readily when one or two water molecules are clustered to the molecule. The results of this work are compared with those obtained on the model compound 4-N,N-dimethylaminobenzonitrile (DMABN), where no TICT emission is observed in small DMABN-(Solvent)(n) clusters.