Intramolecular charge transfer dual fluorescence of p-dimethylaminobenzoates.

A series of ester, p-N,N-dimethylaminobenzoates ((CH3)2NC6H4COOR, R=n-CnH2n+1, n=1,2,...8), were synthesized and their fluorescence spectra were recorded. Intramolecular charge transfer (CT) dual fluorescence was found in common organic solvent or in water with cetyltrimethylammonium bromide (CTAB) micelle. The fluorescence intensity ratio of CT band to normal band (ICT/ILE) was decreased dramatically with the increasing of carbon number of R group when the carbon number of R group were 1-3, but the dependence was not obvious when the carbon number of R group were 4-8. Oppositely, the ICT/ILE was increased with increasing of carbon number of R group in water with CTAB micelle.