Two isostructural Cd(II) coordination polymers showing different adsorption behaviors toward methyl orange (MO)

Abstract

Two isostructural Cd(II) coordination polymers (CPs), namely {[Cd(L)(H₂O)₂](ClO₄)₂}_n (I) and {[Cd(L)(H₂O)(dca)](ClO₄)}_n (II), have been synthesized by assembling a multidentate building block 3,4-bis(3-pyridyl)−5-(4-pyridyl)−1,2,4-triazole (L) with Cd(ClO₄)₂ in the absence or presence of sodium dicyanamide (Na(dca)). Single-crystal X-ray diffraction reveals that both CPs show the similar 2D-layered structures. Interestingly, they present distinct adsorption capacities (7% for I and 18% for II) toward the anionic dye methyl orange (MO). The results indicate that complex II shows higher adsorption ability, which may be ascribed to the charge effect of cationic framework.

Keywords:

• Cd(II) coordination polymers
• dye adsorption
• methyl orange

Additional information

Funding

This work was supported by the Program for Innovative Research Team in University of Tianjin (TD13-5074) and Tianjin Natural Science Foundation (17JCYBJC22800).