Solvent Induced Diverse Dimensional Coordination Assemblies of Cupric Benzotriazole-5-carboxylate: Syntheses, Crystal Structures, and Magnetic Properties

Abstract

Three cupric coordination assemblies [Cu(btca)(H(2)O)(2)] (1), [Cu(btca)(H(2)O)(3.5)](8)·16H(2)O (2), and [Cu(2.5)(btca)(1.5)(Hbtca)(0.5)(μ-Cl)(0.5)(μ(3)-OH)(H(2)O)]·H(2)O (3) have been solvothermally synthesized by cupric salts and a bifunctional ligand benzotriazole-5-carboxylic acid (H(2)btca) in different solvent medium. These complexes were structurally characterized by X-ray diffraction analyses and further identified by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). Single crystal structural analysis shows that these coordination compounds assembled by the almost same reactants present diverse dimensional crystal structures, wherein 1 possesses two-dimensional (2D) layers with (4.8(2)) topology, the zero-dimensional (0D) neutral metallomacrocycle with flat octagonal geometry in 2 connects each other through hydrogen bonding to extend to be a three-dimensional (3D) nanotubular network, and 3 exhibits 3D framework with 1D honeycomb channels constructed by the strip-shaped chains containing [Cu(5)(μ(3)-OH)(2)(btca)(4)](-) pentaclusters bridging to the adjacent Cu(6)(btca)(12)(6-) cages. The diversity of these structures mainly stems from the versatile coordination modes of the anionic ligand in each compound, especially the 1,2,3-triazolate group: bidentate μ(1,2) bridging mode in 1, bidentate μ(1,3) bridging mode in 2, and tridentate μ(1,2,3) bridging mode in 3, respectively. Furthermore, the magnetic properties of 1-3 have been investigated as well.