Nucleophilic Addition-Triggered Lanthanide Luminescence Allows Detection of Amines by Eu(thenoyltrifluoroacetone)3

Herein, a novel fluorescent indicator for the real-time monitoring of amines is described. This probe contains a complex of europium-(thenoyltrifluoroacetone) 3 (Eu(TTA) 3 ) that efficiently reacts with primary and secondary amines. The electron-withdrawing trifluoroacetyl undergoes a nucleophilic addition with amines, and the complex was used to selectively detect BuNH 2 and Et 2 NH (quenching concentration for BuNH 2 : 10 −4 m , for Et 2 NH: 1.2 × 10 −3 m ) by monitoring emission; no changes were observed in the emission spectrum of Eu(TTA) 3 in the presence of Et 3 N, [Bu 4 N]Cl, or PhNH 2 in aqueous solution (THF/H 2 O = 1:1). The ratio of emission intensity to amine concentration was linear by the least-squares fitting method.