Vinyl monomers bearing chromophore moieties and their polymers. V. Synthesis and fluorescence behavior of a vinyloxy monomer bearing electron-accepting chromophore moiety,N-(2-(vinyloxy)ethyl)-1,8-naphthalimide, and its polymer

Abstract

A vinyloxy monomer bearing electron-accepting chromophore, N-(2-(vinyloxy)ethyl)-1,8-naphthalimide (VOENI), was synthesized by reaction of potassium 1,8-naphthalimide with 2-chloroethyl vinyl ether. VOENI can be homopolymerized by cationic initiation and copolymerized with maleic anhydride (MAn) under radical initiation. The fluorescence behaviors of VOENI and its polymers were investigated. It has been found that the fluorescence intensity of the VOENI monomer is much lower than that of its polymers at the same chromophore concentration. This means that a “structural self-quenching effect” (SSQE) has been also observed in the vinyloxy monomer consisting of an electron-accepting chromophore, which has opposite electronic structure in comparison with acrylates bearing electron-donating chromophores as we have reported previously. The SSQE is attributed to the charge-transfer interaction between the electron-accepting chromophore and the electron-donating double bond in the same molecule. The fluorescence quenching of 1,8-naphthalic anhydride and P(VOENI-co-MAn) by ethyl vinyl ether (EVE), dihydrofuran, triethylamine (TEA), etc. evidences that the electron-rich vinyloxy group does act as an important role in the SSQE of VOENI. C60 can also quench the fluorescence of the polymers, and an upward deviation from the linearity of the Stern–Volmer plot was observed showing that C60 acted as a powerful electron donor to quench the fluorescence of the copolymer. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1111–1116, 1998