title: Triazole-modified calix[4]crown as a novel fluorescent on-off switchable chemosensor.
abstract: A novel fluorescent on-off switchable chemosensor 1 with two different types of cationic binding sites is synthesized, which is composed of a triazole-modified calix[4]crown in the 1,3-alternate conformation. Among 15 metal ions examined, the fluorescence of 1 was strongly quenched by Hg2+, Cu2+, Cr3+, and Pb2+; however, the revival of emission from the strongly quenched 1.Pb2+ complex was achievable by the addition of K+, Ba2+, or Zn2+ ions. Thus, metal ion exchange can trigger an on-off switchable fluorescent chemosensor.
authors.affiliation: Department of Applied Chemistry, National Chiao-Tung University, Hsinchu, 30050, Taiwan, Republic of China.
authors.forename: Kai-Chi
authors.initials: KC
authors.lastname: Chang
authors.forename: In-Hao
authors.initials: IH
authors.lastname: Su
authors.forename: Annamalai
authors.initials: A
authors.lastname: Senthilvelan
authors.forename: Wen-Sheng
authors.initials: WS
authors.lastname: Chung