Controlling structural topology of metal-organic frameworks with a desymmetric 4-connected ligand through the design of metal-containing nodes

Two new metal-organic frameworks (MOFs), [Cu-2(H2O)(2)(BCPIA)] (BUT-20) and (Me2NH2)[In(BCPIA)] (BUT-21) were designed and synthesized through the solvothermal reaction between a newly created desymmetric 4-connected ligand, 5-(2,6-bis(4-carboxyphenyl)pyridin-4-yl)isophthalic acid (H(4)BCPIA) and Cu(NO3)(2)center dot 2.5H(2)O or In(NO3)(3)center dot 5H(2)O, respectively, and characterized by single-crystal and powder Xray diffraction, thermogravimetric analysis, infrared spectroscopy, and elemental analysis. The two MOFs have three-dimensional structures, in which both the BCPIA(4-) ligand and metal-containing entities, Cu-2(COO)(4)(H2O)(2) and In(COO)(4) act as 4-connected nodes. However, different linkage configurations of the two metal-containing nodes, quadrilateral Cu-2(COO)(4)(H2O)(2) and tetrahedral In(COO)(4), lead to distinct structural networks of BUT-20 and -21, with Nbo and Unc topologies, respectively. (C) 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.