A Zn-coordination polymer as a multifunctional fluorescent probe for the detection of V 2 O 7 4- , Fe 3+ , and p -nitrotoluene

A transition metal coordination polymer, [Zn(tpba)(bqdbc) ] (1), was successfully designed and synthesized based on 2,2'-biquinoline-4,4'-dicarboxylic acid (H bqdc) and 4-(2,2';6',2'-terpyridin)-4'-yl)benzoic acid (Htpba). Compound 1 is initially constructed from the 1D chain of tpba and bqdc and further connected by π⋯π interactions, forming a 2D layered structure. Notably, compound 1 showed good fluorescence stability ranging from pH 1 to 13 in an aqueous solution. It was found that compound 1 could not only detect V O ions with high selectivity and recyclability but also serve as an excellent selective sensing material for Fe among some cations. More crucially, it is the first time that a luminescent coordination polymer has been used to detect V O ions in aqueous solution. The detection of nitrotoluene ( -NT) demonstrated that compound 1 could also behave as a functional probe with high selectivity, sensitivity, and recyclability; and the detection limit of -NT was 50.9 nM. Meanwhile, the luminescence sensing mechanisms for different analytes were speculated in detail.