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Updated: Jun 5, 2026

Synthesis of Triazole and Tetrazole-Functionalized Zr-Based Metal-Organic Frameworks Through Post-Synthetic Ligand Exchange
Published on: June 23, 2023
Poly[diaqua-di-μ(4)-citrato-trizinc(II)]
1College of Chemistry and Ecological Engineering, Guangxi University for Nationalities, Nanning 530006, Guangxi, People's Republic of China.
Abstract:
The title compound, [Zn(3)(C(6)H(5)O(7))(2)(H(2)O)(2)](n), is a polymer in which the repeating unit contains three zinc atoms, two hepta-dentate Hcit ligands (Hcit = citric acid trianion) and two coordinated water mol-ecules, only half of which are independent due to one of the metal atoms lying on a centre of symmetry. The two independent cations both exhibit an octa-hedral geometry, but the way in which they are coordinate are different; while the Zn atom in a general position is bound to three Hcit ligands and one water mol-ecule, the one at the centre of symmetry is coordinated by six O atoms from two symmetry-related Hcit ligands through the (protonated) hydroxyl and carboxyl-ate groups. The three carboxyl-ate groups coordinate to the Zn centres in three different ways, viz. chelating, bridging and a mixture of both, in an unusual coordination mode for citrate. The result is a two-dimensional structure parallel to (010), built up by a square-grid motif. Intermolecular O-H⋯O hydrogen bonds are present in the crystal structure.
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