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An Imidazole-Functionalized Polyoxovanadate with a Classical {V₁₈O₄₂} Core and Its Photothermal Conversion Behavior.

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¹College of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Intelligent Molecular Science and Engineering, Qingdao University, Qingdao 266071, China.

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|May 26, 2026

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Area of Science:

Inorganic Chemistry
Materials Science
Supramolecular Chemistry

Background:

The {V₁₈O₄₂} cage is a key polyoxovanadate (POV) structure with tunable V(IV)/V(V) ratios.
Organic functionalization of the {V₁₈O₄₂} cage is underexplored, limiting its potential applications.

Purpose of the Study:

To synthesize and structurally characterize an organic-functionalized {V₁₈O₄₂} cage.
To investigate the photothermal conversion properties of the novel compound.

Main Methods:

Single-crystal X-ray diffraction for structural determination.
Bond valence sum and X-ray photoelectron spectroscopy for valence state analysis.
UV-Vis spectroscopy and photothermal conversion experiments under 660 nm irradiation.

Main Results:

Synthesis and structural characterization of H[(VO)(mIM)₄]₄[V₁₈O₄₂(Cl)]·13H₂O (V₂₂-mIM), the first organic-functionalized {V₁₈O₄₂} cage.
Confirmation of a mixed-valence state with 18 V(IV) and 4 V(V) centers.
Demonstration of broad visible-light absorption and pronounced photothermal conversion in solution and solid states with stable cycling.

Conclusions:

This work presents the first structurally defined organic-functionalized {V₁₈O₄₂} cage.
The mixed-valence polyoxovanadate exhibits efficient photothermal conversion, highlighting its potential as a molecular platform for such applications.