A 2D pillared-bilayer iron-based metal–organic framework: syntheses, crystal structure, UV-light photocatalytic and heterogeneous Fenton-like catalytic activities

A two-dimensional (2D) pillared-bilayer iron-based metal–organic framework (MOF), [Fe 2 (aip) 2 (bpy) 2 ]·(H 2 O)(DMF) ( 1 ) (where H 2 aip = 5-aminoisophthalic acid, bpy = 4,4'-bipyridine, DMF = N , N -dimethylformamide), was solvo/hydrothermally synthesized using H 2 aip, bpy and ferrous sulfate heptahydrate as raw materials in DMF/H 2 O mixed solvent. The structure and properties of 1 were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, thermogravimetric analysis, infrared spectroscopy and UV–vis diffuse reflectance spectroscopy. In 1 , each Fe(II) ion exhibits a distorted octahedral geometry, while the aip 2− and bpy ligands adopt the chelating/bridging bis-bidentate (μ 3 -η 1 :η 1 :η 2 ) and bridging bidentate (μ 2 -η 1 :η 1 ) coordination modes, respectively. Infinite one-dimensional [Fe 2 (aip) 2 ] n chains extending along the a axis are formed through bridging and chelating carboxylate groups of aip 2− ligands and are further cross-linked by bpy ligands along the b axis to generate an infinite 2D pillared-bilayer framework with an interdigitated structure. Fe-MOF 1 shows both UV-light photocatalytic activity and Fenton-like catalytic activity toward the degradation of rhodamine B solution, which can be potentially applied in environmental remediation such as industrial wastewater treatment.