Related Experiment Video
Updated: Jul 9, 2025

Author Spotlight: Functionalizing Metal-Organic Frameworks: Advancements, Challenges, and the Power of Post-Synthetic Ligand Exchange
Published on: June 23, 2023
Asymmetric dinuclear, hexanuclear and octanuclear oxovanadium citrates with triazolates: novel mixed-ligands and
Zhen-Lang Xie1, Zhao-Hui Zhou1
1State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China. zhzhou@xmu.edu.cn.
Abstract:
The triazolate-assisted asymmetric dinuclear oxovanadium(IV) citrate [V2O2(cit)(Hdatrz)3]·5H2O (1, H4cit = citric acid, Hdatrz = 1H-1,2,4-triazole-3,5-diamine) and its additive salt [V2O2(cit)(Hdatrz)3][V2O2(cit)2]½·2H2datrz·9.5H2O (2) and the polymerized hexanuclear product [V6O6(μ3-O)2(cit)2(Hdatrz)4]·4H2O (3) have been isolated at different temperatures, respectively. Adduct 2 shows strong evidence for the conversion of a symmetric dinuclear oxovanadium(IV) citrate to a mixed-ligand asymmetric oxovanadium(IV) citrate. Moreover, a fully oxidized trinuclear vanadium(V) species [V3O6(μ2-OH)(μ3-O)(Hdatrz)2]·4.5H2O (4) has also been isolated as a quasi-intermediate product of 3 without the coordination of citrate. Intriguingly, an octanuclear mixed-valence oxovanadium(V/IV) citrate K2{[VIV/V2O2(cit)(Hdatrz)(datrz)]2[VIV2O2(cit)(Hdatrz)(datrz)]2}·27.5H2O (5) has been obtained with different vanadium units, where dinuclear mixed-ligands and mixed-valence oxovanadium(IV/V) citrates [VIV/V2O2(cit)(Hdatrz)(datrz)] (5a) and [VIV2O2(cit)(Hdatrz)(datrz)] (5b) have been trapped. Citrate adopts a μ2-η1:η1:η1:η2 coordination mode in 1, 2 and 5, while a μ3-η1:η1:η1:η2 fashion has been observed in 3. Unlike 1-4, complex 5 contains both protonated and deprotonated triazolates simultaneously, where four triazolates further coordinate in a μ3-η1:η1:η1 manner to construct an octanuclear unit. These different structural features in 1-5 are dominated by flexible multidentate citrates and protonated/deprotonated triazolates, showing their synergistic effects. Furthermore, 1 exhibits a rectangular channel, showing preferential adsorption of O2 and CO2 over gases N2, H2, and CH4.
More Related Videos
11:14Anticancer Metal Complexes: Synthesis and Cytotoxicity Evaluation by the MTT Assay
Published on: November 10, 2013
09:45Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Related Concept Videos
Valence Bond Theory
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Coordination Number and Geometry
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Coordination Compounds and Nomenclature