Synthesis, Structure, and Properties of Complexes Based on 2,4-Bis-(triazol-1-yl)benzoic Acid as a Ligand.

Using 2,4-bis-(triazol-1-yl)-benzoic acid as the main ligand and terephthalic acid (TPA) as the auxiliary ligand, combined with Cd(NO)·4HO and Zn(NO)·6HO, self-assembly under solvothermal conditions gave three novel complexes: [Cd(L)(HO)] (), [Cd(L)(TPA)(HO)]·HO (), and [Zn(L)(TPA)]·HO () (TPA = terephthalic acid). The crystal structure test showed that complex belongs to the triclinic crystal system and the 1̅ space group and complexes and belong to the monoclinic crystal system and the 2/ space group. Solid-state fluorescence experiments show that complexes , , and all have excellent optical properties: among them, complexes and can selectively detect MnO with low detection limits (0.96 μM and 0.232 μM, respectively) and complex can detect CrO [limit of detection (LOD) = 0.035 μM], and the most interesting thing is that all three complexes can be used as sensors for detecting Fe (LOD = 0.76 μM, 0.657 μM, and 0.11 μM, respectively). In addition, the detection capabilities of these three complexes for different amino acids and antibiotics were also analyzed, and the results showed that all three complexes can effectively detect tetracycline hydrochloride through the quenching effect and and can selectively detect tryptophan via the fluorescence enhancement effect.