Study on magnetic and dye adsorption properties of five coordination polymers based on triazole carboxylic acid ligands

Five new coordination polymers based on triazole carboxylic acid ligands, namely {[Mn2(L1)2(H2O)2] center dot H2O}n (1), [Ni2(L1)2(H2O)2]n (2), { [Co2(L1)2(H2O)2] center dot 0.5H2O}n (3), [Cu(L2)2(H2O)]n (4) and [Zn(L3)(H2O)Cl]n (5) [H2L1= 5-((4-(1H-1,2,4-triazol-1-yl)benzyl)amino)isophthalic acid, HL2 = 4-((4-(1H-1,2,4-triazol-1-yl)benzyl)amino)benzoic acid, HL3= 4-(((1H-1,2,4-triazol-3-yl)amino)methyl)benzoic acid] were hydro-/solvothermally synthesized and further characterized by Fourier transform in-frared spectroscopy (FTIR), differential scanning calorimeter (DSC) and X-ray crystal diffraction. X-ray single-crystal diffraction revealed that complexes 1 -3 are two-dimensional (2D) layered architectures, complex 4 and 5 are chain structures, and 5 further forms a 2D supramolecular structure through hydrogen-bonding interactions. The magnetic properties of complexes 1 -4 were studied and the results showed that complexes 1 -4 have antiferromagnetic behavior. In addition, complex 5 exhibits adsorption performance to Congo red (CR), the maximum adsorption capacity is 263.2 mg center dot g -1, and the adsorption isotherm, adsorption kinetics, effect of pH and cycling performance were investigated in detail. (c) 2023 Elsevier B.V. All rights reserved.