title: Fluorescence turn on of coumarin derivatives by metal cations: a new signaling mechanism based on C=N isomerization.
abstract: [reaction: see text] A new sensing mechanism based on C=N isomerization, which shows a very significant fluorescence enhancement to the metal cations in a simple and efficient way, is demonstrated. A coumarin derivative (L) containing a C=N group was designed as an example for illustration. The free ligand L is almost nonfluorescent due to the isomerization of C=N double bond in the excited state. However, the solution of ligand shows about a 200-fold increase of fluorescence quantum yield (about 30%) upon addition of Zn(ClO4)2.
authors.affiliation: Nano-Organic Photoelectronic Laboratory, Laboratory of Organic Optoelectronic Functional Materials and Molecular Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100080, PR China.
authors.forename: Jia-Sheng
authors.initials: JS
authors.lastname: Wu
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Liu
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Zhuang
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Wang
authors.forename: Si-Lu
authors.initials: SL
authors.lastname: Tao
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Zhang
authors.forename: Shi-Kang
authors.initials: SK
authors.lastname: Wu
authors.forename: Shuit-Tong
authors.initials: ST
authors.lastname: Lee