Synthesis and structure-photophysical property relationships for two coumarinyl-based two-photon induced fluorescent molecules

The synthesis and the structure-photophysical property relationships for two new cournarinyl-based organic heterocyclic molecules are presented. These molecules consist of a typical A-pi-D or A-pi-A' structure, where 3-carbonylcoumarinyl, vinyl and anthryl (or indolyl) groups are employed as acceptor (A), pi-conjugated center (pi) and donor (D) (or the other acceptor, A') moieties, respectively. Based on steady-state as well as time-resolved techniques, it is found that this new kind of pi-conjugated framework consisting of a 3-carbonylcoumarinyl acceptor and a vinyl pi-conjugated center is a useful conjugated pi-electron building block with potential applications in forming new kind of effective organic two-photon induced fluorescence (TPIF) molecules. Additionally, experimental results confirm that remarkable enhancements in the fluorescence quantum yield and TPIF activity can be obtained by replacing anthryl group with an indolyl group in the terminal moiety of the coumarinyl-based pi-conjugated framework. (C) 2003 Elsevier B.V. All rights reserved.