An unusual 2D nanoscaled quadruple-layer metal-organic framework based on octanuclear cobalt clusters

摘要

Self-assembly of a flexible tricarboxylate ligand (H3L) and cobalt salt under hydrothermal conditions yields an unprecedented two-dimensional (2D) nanoscaled quadruple-layer networks [Co-4(HL)(3)(mu(3)-OH)(2)(H2O)(2)]center dot 5H(2)O (1) (H3L = (3,5-dicarboxyl-phenyl)-(4-(2'-carboxyl-phenyl)-benzyl)ether). The structure of compound 1 was determined by single-crystal X-ray diffraction analysis and further characterized by elemental analyses, IR spectrum, and thermogravimetric analysis. Compound 1 represents the first 20 nanoscaled multiple-layer architecture constructed from octanuclear cobalt cluster building blocks. Furthermore, the adjacent sidearm-containing 2D quadruple-layer motifs are interdigitated in a mutual relationship to form a 3D supramolecular framework. In addition, the magnetic properties of compound 1 have been studied by measuring its magnetic susceptibility in the temperature range of 2-300 K, indicating the existence of antiferromagnetic coupling within the octanuclear cobalt cluster. (C) 2015 Elsevier B.V. All rights reserved.