An ionic luminescent complex of europium(III) and its fluorescence sensing performance for amine VOCs

A new fluorescent amine probe of ionic complex (MV) [Eu(NTA)4)]2 (1) (MV = Methyl viologen, NTA = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione) has been designed and synthesized. Single-crystal X-ray diffraction shows that 1 crystallizes with four independent mononuclear cationic complexes, solvated by two hexane, one dichloromethane, one alcohol and three water molecules counterbalanced by two MV2+ cations (1•hexane•0.5DCM•0.5EtOH•1·5H2O). Both in solid state and in doped films, this probe material exhibits strong red fluorescence emission dominated by 5D0→7F2 transition of Eu3+ ions. On the basis of this complex fluorescence probe, a paper-based thin film fluorescence sensor with fast and sensitive sensing performance to cyclohexylamine (CYA) was developed by PMMA composite preparation process. When the paper based sensor is placed in an atmosphere containing CYA vapor, its photoluminescence (PL) intensity decreases rapidly, showing a typical fast quenching fluorescence sensor.