Synthesis and Characterization of a 3D Coordination Polymer Based on Trinuclear Triangular Cu<sup>II</sup> as Secondary Building Units

The hydrothermal reaction of Cu<sup>II</sup> salts with 1,2,4-triazole (Htrz) in aqueous ammonia yielded a novel metal−organic framework {[Cu<sub>3</sub>(μ<sub>3</sub>-O)(μ<sub>3</sub>-trz)<sub>3</sub>(OH)(H<sub>2</sub>O)<sub>6</sub>]}<i><sub>n</sub></i> (<b>1</b>), which was characterized by single-crystal X-ray diffraction, X-ray powder diffraction, thermogravimetric analysis, IR, and variable-temperature magnetic susceptibility. It crystallizes in cubic, space group <i>Fd</i>3̄<i>c</i> with<i> a </i>= 24.644(3) Å,<i> V </i>= 14967(3) Å<sup>3</sup>, and <i>Z </i>= 96. Its framework is the first 3D structure using coordinative interactions constructed via trinuclear triangular Cu<sup>II</sup> secondary building units, in which both Cu<sup>II</sup> ions and trz ligands act as three-connected nodes to form a 6.8<sup>2</sup> net. An overall antiferromagnetic behavior was found in the compound.