Four coordination polymers based on 5-(3,5-dicarboxybenzyloxy) isophthalic acid: Synthesis, structures, photocatalytic properties, fluorescence sensing and magnetic properties

Highlights: • Four new Coordination polymers were synthesized and characterized. • CPs 2–4 can serve as a highly selective Fe³⁺ ion luminescent sensor, each of which possesses a low detection limit. • CPs 1–4 exhibited obvious degradation effect on MB. Especially for CP 4, the degradation efficiency reached up to 84%. Four coordination polymers named [Co(L)_0.5(bib)]_n (1), Zn(H₂L)(bib)]·2H₂O}_n (2), Cd(L)_0.5(1,2-bimb)]_n (3) and Zn(L)_0.5(bib)]_n (4) (H₄L=5-(3,5-dicarboxybenzyloxy) isophthalic acid, bib=1,4-bis(1-imidazolyl)benzene, and 1,2-bimb=1,2-bis(1-imidazolylmethyl)benzene) were synthesized by solvothermal method and structurally characterized by means of single-crystal X-ray diffraction, infrared spectra and elemental analyses. Complex 1 crystallized in orthorhombic space group Pbcn had a 2-fold interpenetrated framework. Complex 2 showed a 4-fold interpenetrated framework. Complex 3 presented a 3-fold interpenetrated framework that crystallized in the triclinic system Pī space group. Complex 4 was a three-dimensional (3D) porous framework. Remarkably, the photocatalytic degradation experiments of complexes 1–4 on methylene blue (MB) indicated that these complexes 1–4 exhibited obvious degradation effect on MB. Moreover, the investigation of the luminescent properties of complexes 2–4 revealed that these complexes 2–4 could be served as a potential highly selective Fe³⁺ ion luminescent sensor. In addition, the magnetic analyses of complex 1 indicated that there was antiferromagnetic interaction between the Co (II) ions in complex 1.