An ultra-stable Cd coordination polymer based on double-chelated ligand for efficient dual-response of TNP and MnO4

[Display omitted] •An ultra-stable luminescent Cd-CP was fabricated large planar double-chelated ligand.•The framework exhibits highly sensitive and selective detection of TNP in DMF.•The dosage of the framework represents the lowest dosage in TNP sensors.•The framework can rapidly, sensitively and circularly detect TNP and MnO4− in H2O.•The sensing mechanisms towards TNP and MnO4− have been elucidated. Exploiting an efficient method to detect nitro-aromatic compounds and anion contaminants remains pressing. Coordination polymers (CPs) are great potential luminescence materials for sensing applications, where π-π interaction is useful for improving sensing performance. A bright luminescent Cd-CP {[Cd2(μ2-OAc)2(L)(bdc)]·L·2H2O}n (1) was prepared by utilizing large planar double-chelated ligand tetrapyrido[3,2-a:2′,3′-c:3″,2″-h:2‴,3‴-j]phenazine (L). Its structure contains [Cd2(μ2-OAc)2] units and two double chelated linkers, and presents a 2D 4-connected sql net. These 2D sql networks are accumulated into a unique 3D supramolecular framework through strong intralayer and interlayer π-π interactions. 1 features excellent water, thermal and pH stabilities. The ultra-stable framework exhibits highly selective and sensitive detection of TNP in DMF with fast response time (15 s), high quenching efficiency Ksv (1.16×105 M−1) and low LOD (0.091 ppm). More importantly, the dosage of 1 in detecting TNP is only 0.02 mg/mL, which represents the lowest dosage in TNP sensors. Meanwhile, 1 can rapidly and sensitively recognize TNP and MnO4- in aqueous system with low LOD (0.046 ppm for TNP, 0.028 ppm for MnO4-). Moreover, this dual-response luminescence sensor exhibits good recyclability. The quenching mechanisms have been discussed in detail. This work will contribute to develop economical and efficient luminescence sensors.