Three Polyoxovanadoborates Constructed from "Sandwich"-Type {V₁₀B₂₄}, {V₁₀B₂₈}, and {V₁₂B₃₂} Clusters

Area of Science:

• Inorganic Chemistry
• Materials Science
• Catalysis

Background:

• Polyoxovanadoborates are complex inorganic clusters with diverse structures and potential applications.
• Transition metal modification offers a route to tune the properties of these polyoxovanadoborates.
• Hydrothermal synthesis is a common method for preparing crystalline inorganic materials.

Purpose of the Study:

• To synthesize novel polyoxovanadoborate compounds modified by transition metals (Cd, Zn, Cu).
• To characterize the structures of the synthesized compounds.
• To evaluate the catalytic activity of the synthesized compounds in sulfide oxidation.

Main Methods:

• Hydrothermal synthesis was employed to prepare three distinct polyoxovanadoborate compounds: {V10B26Cd8(phen)12} (1), {V10B32Zn6} (2), and {V12B32Cu2} (3).
• Structural characterization was performed on the synthesized compounds.
• Catalytic oxidation experiments were conducted to assess the performance of compound 2 in sulfide oxidation.

Main Results:

• Three unique sandwich-type polyoxovanadoborate clusters ({V10B24}, {V10B28}, and {V12B32}) were synthesized and characterized.
• Compound 1 features {Cd(phen)} and {Cd(phen)2} units grafted onto a {V10B24} cluster.
• Compound 2 forms a 1D polymeric chain with a {V10B28} cluster and a {Zn4B4O8} unit, showing efficient and stable sulfide oxidation catalytic activity.
• Compound 3 forms a 3D supramolecular framework through the interconnection of a {V12B32} cluster with [Cu(en)2]2+.

Conclusions:

• Novel transition metal-modified polyoxovanadoborates with unique structural motifs have been successfully synthesized.
• Compound 2 exhibits promising catalytic activity and stability for sulfide oxidation, highlighting its potential in catalytic applications.
• The structural diversity achieved through transition metal incorporation suggests further possibilities for designing functional polyoxovanadoborate materials.