Multi-maleimides bearing electron-donating chromophores: Reversible fluorescence and aggregation behavior

A(=)-D, [A(=)]2-D and [A (=)]3-D multi-maleimides and multi-itaconimides bearing electron-donating chromophores display a strong fluorescence quenching due to an intramolecular charge-transfer interaction. The electron-accepting C=C bond plays a key role in the intramolecular quenching. For the isomerization of these multi-itaconimides and Michael additions of these multi-maleimides, their emission behavior is irreversible. For the Diels-Alder additions of these multi-maleimides, their emission behavior is reversible due to the reversible opening and closing of intramolecular charge-transfer pathway. Tris-maleimide TMPA peripherally modified with furfural alcohol displays not only reversible fluorescence behavior but also reversible aggregation behavior. Copyright © 2004 American Chemical Society.