Highly selective and sensitive detection of 4-nitrophenol and Fe3+ ion based on a luminescent layered terbium (III) coordination polymer

A luminescent terbium(III)-based coordination polymer, [Tb(BTEC)(0.5)(HCOO)(H2O)(2)] (1) has been successfully synthesized by solvothermal reaction of Tb(NO3)(3).6H(2)O with 1,2,4,5-tetracarboxylic acid (H4BTEC) in N,N-dimethylformamide (DMF) and H2O at 160 degrees C. Compound 1 possesses dimeric [Tb-2(BTEC)(4)(HCOO)(2)(H2O)(4)] building blocks which are linked by BTEC linkers to generate a twodimentional honeycomb layer. 1 shows intense characteristic green emission in both solid state and organic solvents including acetone, ethanol, acetonitrile, benzene, dichloromethane, methanol, tetrahydrofuran, dimethyl sulfoxide and water at ambient temperature. Strong emission of 1 could be highly and selectively quenched by 4-nitropenol (4-NP) even in the coexistence of other competing nitroaromatics such as 2,4,6-trinitrophenol, 2,6-dinitrotoluene, nitrobenzene, 4-nitrotolune, 4-bromophenol, phenol, bromobenzene, and 1,2-dimethylbenzene. In addition, 1 exhibited superior selectivity and sensitivity towards Fe3+ ion over other metal ions including Al3+, Ca2+, Cd2+, Co2+, Cr3+, Cu2+, Ni2+, Mg2+, Mn2+ Pd2+ and Zn2+ ions. The possible detection mechanisms have been proposed. More interestingly, the trace amounts of 4-NP and Fe3+ ions were selectively detected using visual luminescent test papers based on 1, which could further contributes a credible potential sensing application of coodination polymers for the biological and environmental concerns. (C) 2017 Elsevier B.V. All rights reserved.