HETEROCYCLES

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

■ Anion-induced Fluorescence Quenching and Excimer Formation of Anthracene-Imidazolium Receptor

Kiyoshi Sato,* Yuichi Sadamitsu, Sadao Arai, Tetsuya Shimada, Haruo Inoue, and Takamichi Yamagishi

*Department of Applied Chemistry, Faculty of Engineering, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan

Abstract

New anthracene based fluorescent anion receptor bearing two imidazolium units linked by methylene spacers at 9,10-positions has been synthesized. Complexation behavior and fluorescent properties of the receptor with inorganic anions (Cl^-, Br^-, I^-, NO₃^-, HSO₄^-, and H₂PO₄^-) in acetonitrile were investigated by ¹H NMR spectrometric and fluorimetric titrations, and fluorescence lifetime measurement. At low receptor concentration level (0.1 μM), fluorescence of the receptor was quenched by formation of 1:1 host-guest complex with the anions. At relatively higher receptor concentrations (above 1.0 μM), H₂PO₄^- anion quenched the monomer emission mainly by the excimer formation due to anion-induced ground state aggregation. Fluorescence lifetime measurements revealed that quenching mechanisms are different between halide ions and oxoanions.