A Three-Dimensional (3D) Indium-Containing Polyoxoniobate Framework Based on {In₅Nb₇₁} Helical Pillars

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• Polyoxoniobates (Nb-O clusters) are versatile inorganic building blocks.
• Indium and copper incorporation can tune material properties.
• Hybrid organic-inorganic frameworks offer unique structural and functional possibilities.

Purpose of the Study:

• To synthesize a novel 3D Indium-containing polyoxoniobate framework.
• To characterize the structure and properties of the synthesized material.
• To investigate its potential applications in ionic conductivity and gas adsorption.

Main Methods:

• Hydrothermal synthesis of the inorganic-organic hybrid framework.
• Single-crystal X-ray diffraction for structural determination.
• Ionic conductivity measurements.
• Gas (vapor) adsorption analysis.

Main Results:

• Successful synthesis of a rare 3D Indium-copper polyoxoniobate framework, denoted as {H9[Cu(en)2(H2O)2][Cu(en)2]12[In(en)]5[Nb23-O65(OH)3(H2O)2]{Nb24O67(OH)2(H2O)3]2}·68H2O (1).
• The framework features a nest-like {In5Nb71} cluster with helical pillars formed by V-shaped and triangle-shapedniobium-oxygen units linked by Indium-ethylenediamine fragments.
• The copper-amine complexes bridge these helical pillars, creating a robust 3D structure.
• The material exhibits good ionic conductivity and significant vapor adsorption capacity.

Conclusions:

• A novel 3D Indium-copper polyoxoniobate framework has been successfully synthesized and characterized.
• The unique structural features, including helical pillars and inorganic-organic hybrid nature, contribute to its functional properties.
• The demonstrated ionic conductivity and vapor adsorption capacity suggest potential applications in energy storage and separation technologies.