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Updated: Jun 16, 2026

Synthesis of Triazole and Tetrazole-Functionalized Zr-Based Metal-Organic Frameworks Through Post-Synthetic Ligand Exchange
Published on: June 23, 2023
NMR and theoretical study on interactions between diperoxovanadate complex and pyrazole-like ligands
Xianyong Yu1, Ronghua Liu, Hongliang Peng
1Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan, China.
Pyrazole substitution significantly impacts vanadium complex reactions, with steric effects, not electronic ones, governing reactivity. This research clarifies ligand interactions and isomer formation in peroxovanadate species.
Area of Science:
- Inorganic Chemistry
- Supramolecular Chemistry
- Computational Chemistry
Background:
- Vanadium complexes are crucial in biological systems and catalysis.
- Understanding ligand interactions with peroxovanadate species is key to controlling their reactivity.
- Pyrazole derivatives are common ligands in coordination chemistry.
Purpose of the Study:
- To investigate the effect of pyrazole substitution on reaction equilibrium with peroxovanadate species.
- To elucidate the factors controlling the reactivity and coordination of pyrazole-like ligands.
- To characterize the resulting vanadium-ligand complexes.
Main Methods:
- Multinuclear magnetic resonance (NMR) spectroscopy ((1)H, (13)C, (51)V).
- Heteronuclear single quantum coherence (HSQC) and variable temperature NMR.
- Density functional theory (DFT) calculations.
Main Results:
- Relative ligand reactivities were determined: 3-methyl-1H-pyrazole ≈ 4-methyl-1H-pyrazole ≈ 1H-pyrazole > 1-methyl-1H-pyrazole.
- Steric effects of the methyl group, not electronic effects, were found to be the primary factor influencing reaction equilibrium.
- Formation of isomers and six-coordinate peroxovanadate species [OV(O(2))(2)L](-) was observed, driven by competitive coordination.
Conclusions:
- Steric hindrance in pyrazole ligands dictates their reactivity with peroxovanadate species.
- Competitive coordination and solvation play significant roles in complex formation and stability.
- DFT calculations support the experimental findings on ligand reactivity and reaction mechanisms.
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