ABSTRACT: A rhodamine derivative (1) was synthesized as a fluorescence turn-on probe for copper (Cu2+) and hypochlorite (ClO−). The probe gave a fluorescence turn-on change at 587 nm with a color change from colorless to pink in the presence of Cu2+ or ClO− ions in aqueous solution. It was found that the Cu2+ ion bound to 1 in a 1:1 stoichiometry and induced a spirolactam ring opening of the rhodamine moiety leading to a fluorescence turn-on, confirmed by Job’s plot, ESI-Mass, and 1H NMR analyses. In the presence of ClO− ion, probe 1 underwent a hypochlorite-mediated oxidation and hydrolysis to produce a ring-opened rhodamine B with a fluorescence enhancement. However, these changes were not monitored in case of other metal ions, anions, and reactive redox species. In addition, probe 1 can readily react with the ClO− to provide a distinct fluorescence enhancement along with a pink color even in the presence of various competitive species.

KEYWORDS: Fluorescence turn-on, Rhodamine hydrazide, Copper detection, Hypochlorite detection 

Author : Jung Won Yoon, Min Jung Chang, Seungwoo Hong*, Min Hee Lee*

Journal :  Tetrahedron Letters 2017 (58) 3887–3893

Publication Date : 2017.08.28 

​This publication is from Prof. Seungwoo Hong’s lab and Prof. Min Hee Lee’s lab