A fluorescent sensor for Zn and NO based on the rational control of C&z.dbd;N isomerization

A new strategy for the ultrasensitive sensing of cations and anions based on the control of C&z.dbd;N isomerization has been developed. Imine-derived ligand L is non-fluorescent due to the C&z.dbd;N isomerization process, whereas its ternary complex with ZnCl 2 is moderately fluorescent because of the partial inhibition of C&z.dbd;N isomerization. Such a ternary complex can give a remarkable fluorescence increase when it interacts with nitrite because of the much more efficient suppression of C&z.dbd;N isomerization. This modulation process of C&z.dbd;N isomerization can thus be used for the highly selective detection of Zn 2+ and NO 2 − in an aqueous solution. L could be used as a fluorescent sensor towards Zn 2+ and NO 2 − based on the control of C&z.dbd;N isomerization.