Anderson-type polyoxometatate-based complexes constructed from a new 'V'-like bis-pyridine-bis-amide ligand for selective adsorption of organic dyes and detection of Cr(VI) and Fe(III) ions

By introducing a new 'V'-like bis-pyridine- bis-amide ligand 4,4'-bis(4-pyridinecarboxamide)phenylmethane (L) into the reaction system based on Anderson-type polyoxometalates (XMo6(OH)(6)O-18](3-) (X = Al or Cr), four metal-organic complexes (MOCs) 1-4, [Zn(HL)(H2O)(2)(XMo6(OH)(6)O18)]center dot.5H(2)O (1: X = Al; 2: X = Cr), (Co(HL)(H2O)(2) (XMo6(OH)(6)O-18)]center dot 5H(2)O (3: X = Al; 4: X = Cr), have been prepared under solvothermal conditions, which have been characterized by single crystal X-ray diffraction, IR spectra, and PXRD. All structures of 1-4 involved a 2D layer that originated from XMo6 polyoxoanions and metal ions, on both sides of which the L ligands were hanged. Complexes 1-4 showed not only outstanding selective adsorption capacities for organic dyes crystal violet, methylene blue and neutral red, but also electrochemical sensing behaviors toward Cr(VI) ions and Fe(III) ions with well-pleasing limits of detection of 0.606 nM (6.24 x 10(-5) ppm) and 0.0192 mu M (1.08 x 10(-3) ppm), suggesting their potential application as multifunctional materials.

Automated summary

A new 'V'-like bis-pyridine-bis-amide ligand was introduced to prepare four metal-organic complexes (MOCs) with remarkable adsorption capacities for organic dyes and electrochemical sensing behaviors toward Cr(VI) ions and Fe(III) ions, suggesting their potential application as multifunctional materials.