Crystal structures of the solid solutions Na₃Zn_0.912Cd_0.088B₅O₁₀ and Na₃Zn_0.845Mg_0.155B₅O₁₀

Area of Science:

• Inorganic Chemistry
• Solid-State Chemistry
• Crystallography

Background:

• Penta-borates are a class of inorganic compounds with diverse structural motifs.
• The parent compound, tris-odium zinc penta-borate (Na3ZnB5O10), serves as a structural template.
• Understanding the incorporation of different metal cations into borate frameworks is crucial for materials science.

Purpose of the Study:

• To synthesize and characterize new penta-borate compounds.
• To investigate the structural properties of solid solutions involving zinc, cadmium, and magnesium.
• To elucidate the role of metal cations in the formation of [M B5O10]3- layers.

Main Methods:

• High-temperature solution reactions at 1023 K for synthesis.
• Single-crystal X-ray diffraction for crystal structure determination.
• Analysis of crystallographic data to identify structural motifs and cation coordination.

Main Results:

• Successfully synthesized two new penta-borates: tris-odium zinc cadmium penta-borate and tris-odium zinc magnesium penta-borate.
• Both compounds crystallize in the ortho-rhom-bic form of Na3ZnB5O10 (space group Pbca).
• The crystal structures contain the [B5O10]5- anion, bridged by disordered M2+ (Zn/Cd, Zn/Mg) cations forming [M B5O10]3- layers with Na+ cations in channels and voids.

Conclusions:

• The study expands the family of known penta-borates with the successful synthesis of new solid solutions.
• The determined crystal structures reveal the formation of layered frameworks stabilized by sodium cations.
• This research contributes to the understanding of structure-property relationships in complex inorganic borates.