Mono-, his-, and trismaleimides (MM-2, BM-4, and TM-6, respectively) bearing electron-donating chromophores generally displayed strong fluorescence quenching. The quenching mechanism of fluorescence was revealed by electrochemical studies. On the basis of the electrochemical data, an energy level diagram was established for these maleimides. The electron-donating ability increased in the order of TM-6 < BM-4 < MM-2. The electron-accepting ability increased in the opposite order, that is, from MM-2 to BM-4 to TM-6. The copolymerization of multimaleimides with diamine could be well monitored by fluorescence spectroscopy. Compared with fluorescence probe techniques, the fluorescence monitoring could directly reflect the consumption of C=C bonds. Furthermore, a novel trismaleimide resin was preliminarily studied, in which TM-6 was a dual-purpose functional monomer acting not only as a crosslinker but also as an intrinsic fluorophore to monitor its crosslinking or cure process. (c) 2005 Wiley Periodicals, Inc.