Three metal–organic frameworks based on the semirigid V-shaped 5-(3-amino-tetrazole-5-phenoxy)-isophthalic acid ligand: syntheses, topological structures and properties

Abstract

The designed organic ligand 5-(3-amino-tetrazole-5-phenoxy)-isophthalic acid (H₂atpia) has been successfully prepared and its coordination features have been explored. By the reaction of H₂atpia with transition metals, three metal–organic frameworks (MOFs), namely [Cd(atpia)]₂ (1), [Cu₃O₂(atpia)₂] (2) and [Mn₃(OH)₂(atpia)₃]·1.25H₂O (3) have been synthesized under hydrothermal conditions. All the compounds were fully characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, power X-ray diffraction and single-crystal X-ray diffraction. These three compounds all display new topologies. Compound 1 exhibits a 3D (2,3,10)-connected framework with (4·6²)₂(4¹²·6¹⁸·8¹¹·10⁴)(4)₂ topology. Compound 2 possesses a 2D 3-nodal layer with (4¹⁶·6¹⁴·8¹¹·10⁴)(4³)₂(4)₂ topology. Compound 3 features a 2D (3,3,8,8)-connected structure with unprecedented (3·4²)₂(3⁴·4⁶·5⁶·6⁸·7³·8) topology. The diverse structures of these three compounds demonstrate that the distinctive coordination modes of different metals have a significant impact on the construction of MOFs. Moreover, the photoluminescence properties of 1 and the magnetic properties of 2 and 3 have been studied and discussed.