Fluorescence turn on of coumarin derivatives by metal cations: a new signaling mechanism based on C=N isomerization.
[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.
Wu
Jia-Sheng
JS
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.
Liu
Wei-Min
WM
Zhuang
Xiao-Qing
XQ
Wang
Fang
F
Wang
Peng-Fei
PF
Tao
Si-Lu
SL
Zhang
Xiao-Hong
XH
Wu
Shi-Kang
SK
Lee
Shuit-Tong
ST