A Two-Dimensional Layered Heteropolyoxoniobate Based on Cubic Sn(IV)-Containing {Sn₁₂Nb₅₆O₂₀₀} Cages with Good Proton...

Area of Science:

• Inorganic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Heteropolyoxoniobates are complex inorganic structures with diverse applications.
• Tin(IV) incorporation into polyoxometalates can modify their properties.
• Proton conductivity in materials is crucial for energy applications.

Purpose of the Study:

• To synthesize and characterize a novel Sn(IV)-containing heteropolyoxoniobate.
• To investigate the structural features and supramolecular assembly of the compound.
• To evaluate the proton conductivity of the synthesized material.

Main Methods:

• Single-crystal X-ray diffraction for structural determination.
• Synthesis of the heteropolyoxoniobate K6H18[Cu(en)2]8{[Sn(OH)2]12(HNb7O22)8}·2en·88H2O (1).
• Proton conductivity measurements under varying temperature and humidity.

Main Results:

• The first example of a Sn(IV)-containing heteropolyoxoniobate, K6H18[Cu(en)2]8{[Sn(OH)2]12(HNb7O22)8}·2en·88H2O (1), was successfully synthesized.
• The structure consists of nanoscale cubic {[Sn(OH)2]12(HNb7O22)8} clusters linked by [Cu(en)2]2+ complexes into 2D layers, forming a 3D supramolecular network via hydrogen bonding.
• Compound 1 demonstrated significant proton conductivity (3.1 × 10^-2 S cm^-1) at 85 °C and 98% relative humidity.

Conclusions:

• The novel Sn(IV)-containing heteropolyoxoniobate exhibits a unique 3D supramolecular architecture.
• The material shows promising proton conductivity, suggesting potential applications in proton-conducting devices.
• This work expands the scope of heteropolyoxoniobate structures and their functional properties.