A series of metal-organic frameworks constructed by a rigid-flexible 5-(bis(4-carboxybenzyl)amino)isophthalic acid: syntheses, crystal structures and physical properties

Four new metal-organic frameworks (MOFs), namely, [Zn2L](n) (1), [Mn(H2L)(H2O)](n) (2), [Cd(H2L)(H2O)(2)](n) nH( 2)O (3) and [Pb2L(H2O)](n) 3nH(2)O nDMF (4), have been prepared by using a tetracarboxylic acid ligand H4L (H4L = 5-(bis(4-carboxybenzyl)amino)isophthalic acid) under hydrothermal conditions and structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction analysis and powder X-ray diffraction. Structural analyses revealed that 1, 2 and 4 exhibit three-dimensional network structures. The structure of 1 can be symbolized as a 2-nodal 6-connected net with a (4(11) 6(4))(4(7) 6(8)) topology. The framework of 2 can be considered as a 4-connected net with a (6(2) 8(4))(6(3) 8(3)) topology. The structure of 4 can be regarded as a 5-connected net with a 4(3) 6(6) 8 topology. In contrast, 3 exhibits a 2D structure with a 3,3-connencted (6(3))(2) topology. These MOFs exhibit excellent photocatalytic activities for dye degradation under visible light irradiation. Furthermore, 2 displays weak antiferromagnetic interaction at low temperature.