Four Anderson-type [TeMo6O24]6−-based metal–organic complexes with a new bis(pyrimidine)-bis(amide): multifunctional electrochemical and adsorption performances

Abstract

Four new isostructural POM-based metal–organic complexes, [H₂X₂(L)₂(TeMo₆O₂₄)(H₂O)₆]·4H₂O [X = Cu (1), Co (2), Ni (3) and Zn (4); L = N,N′-bis(4-pyrimidinecarboxamido)-1,4-benzene], were synthesized with a new rigid bis(pyrimidine)-bis(amide) ligand by varying the central metal under hydrothermal conditions, and characterized by means of single crystal X-ray diffraction, IR spectra and powder X-ray diffraction (PXRD). Complexes 1–4 exhibit similar 2D supramolecular structures based on the [H₂X₂(L)₂(TeMo₆O₂₄)(H₂O)₆] dinuclear units linked through hydrogen bonds. Complexes 1–4 not only show good electrochemical sensing properties for BrO³⁻, NO²⁻, hydrogen peroxide and ascorbic acid, but can also be used as adsorbents for the removal of organic dyes such as gentian violet and methylene blue. Among them, complex 4 has the lowest detection limit and best dye adsorption capacity. Alternatively, the effect of central metals on the properties of the title complexes was discussed.