A vinyloxy monomer bearing of electronaccepting chromophore

p-vinyloxymethylbenzonitrile (VOMBN) and its saturated model compound

p-ethoxymethylbenzonitrile (EOMBN)

were synthesized. VOMBN can be cationically homopolymrized by initiation of Lewis acid such as BF3·Et2O and copolymerized with maleic anhydride (MAn) using AIBN as an initiator. By fluorescence study

it has been found that the fluorescence in tensity of VOMBN is much lower than those of the copolymer P(VoMAn) and EOMBN at the same chromophore concentration.This means that a"Structural Self-Quenching Effect"(SSQE) has been also observed in VOMBN

which is attributed to the charge transfer interaction between the electron-accepting cyanophenyl chromophore and the electron-donating vinyloxy group in the same molecule upon UV irradiation.The fluorescence of EOMBN and P(Vo-MAn) can be quenched by a series of electron-rich vinyloxy compounds such as dihydrofuran (2H-furan)

dihydropyran(2H-pyran)

furan and ethyl vinyl ether(EVE)

which do not have chromophore moieties.It is found that the higher the electron-donating ability of the quenchers which are represented by their ionization potentials

the higher the quenching efficiency.