Luminescent detecting of Fe3+ and Cr2O72− ions by three ternary 2D coordination polymers

Abstract

To investigate the effects of central metal ions on the structures and luminescent sensing properties of ternary luminescent coordination polymers, three new complexes, {[Co(L)(TBTA)(H2O)2]·H2O}n (1), {[Zn(L)(TBTA)]·1.9H2O}n (2) and [Cd(L)(TBTA)]n (3) (L = 1,4-bis(5,6-dimethylbenzimidazol-1-yl)-2-butylene, H2TBTA = tetrabromoterephthalic acid), were synthesized and characterized. 1 and 3 reveal a sql layer, whereas 2 displays a hcb network. Three compounds can be used as probes for the sensitive sensing of Fe3+ and Cr2O72− ions by a luminescence quenching process. The limits of detection (LOD) of 1, 2 and 3 for the detection of Fe3+ ions are 1.61, 1.13 and 0.71 μM, respectively, while the LOD for the sensing of Cr2O72− ions are 1.95, 2.31 and 1.84 μM, separately Possible mechanisms for the luminescence quenching process toward Fe3+ and Cr2O72− ions are presented. The central metal ions of the three ternary CPs play a key role for the effective detection of Fe3+ ions.