Two novel LMOFs based on the flexible 1, 3-bis(imidazol-1-ylmethyl)benzene: The synthesis, crystal structures and temperature sensing applications

Two novel coordination polymers (CPs), namely [Zn(cca)(mbix)] (complex 1) and [Cd-2(IMB)(2)(mbix)(2)]center dot 3H(2)O (complex 2) (H(2)cca = 4-carboxycinnamic acid, mbix = 1,3-bis(imidazol-1-ylmethyl)benzene, H2IMB = 4,4'-((1H-imidazole-1-yl)methylene)dibenzoic acid) have been synthesized by using the solvothermal method. The structure of complexes 1 and 2 were characterized with single-crystal X-ray diffraction analysis, IR spectra (IR), elemental analyses and thermogravimetric (TG) analysis. Good phase purity of complexes 1 and 2 were confirmed by powder X-ray diffraction (PXRD) tests. Complex 1 crystallizes in the orthorhombic space group Pna2(1). In complex 1, each Zn(II) ion is linked by two cca(2-) anions and two mbix ligands to generate a typical three-dimensional (3D) 4-fold interpenetrated diamondoid network. While, complex 2 crystallizes in the monoclinic system with P2(1)/c space group and exhibits the 2D layer structure. Interestingly, complex 2 exhibits linear response toward to the ambient temperature variation and good reusability in the temperature sensing application, which suggests that the as-synthesized MOFs might be used as quantitative fluorescent thermometers. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Two novel coordination polymers, complex 1 and complex 2, have been synthesized using the solvothermal method and characterized through various analyses. Complex 1 exhibits a typical three-dimensional diamondoid network structure, while complex 2 displays a two-dimensional layer structure and shows linear response to ambient temperature variation with good reusability.