Peroxo-Zr/Hf-containing undecatungstosilicates and -germanates

Area of Science:

• Inorganic Chemistry
• Materials Science
• Catalysis

Background:

• Heteropolytungstates are versatile inorganic compounds with diverse applications.
• Peroxo-containing metal complexes can act as potent oxidants.
• Keggin polyanions offer a robust structural framework for functionalization.

Purpose of the Study:

• To synthesize and characterize novel dimeric, peroxo-containing heteropolytungstates.
• To investigate the electrochemical properties and reactivity of these new compounds.
• To explore their potential as oxo-transfer agents.

Main Methods:

• Synthesis of dimeric heteropolytungstates via reaction of metal chlorides with monolacunary Keggin precursors.
• Characterization using techniques such as cyclic voltammetry and exhaustive electrolysis.
• Oxo-transfer studies using l-methionine as a substrate, monitored by proton nuclear magnetic resonance ((1)H NMR).

Main Results:

• Successful synthesis of three isostructural dimeric heteropolytungstates: [M(2)(O(2))(2)(XW(11)O(39))(2)](12-) where M=Zr(4+), Hf(4+) and X=Si, Ge.
• Electrochemical studies revealed facile reductive release of peroxo ligands.
• Demonstrated stoichiometric oxo-transfer capabilities to l-methionine.

Conclusions:

• The synthesized dimeric heteropolytungstates represent a new class of peroxo-containing inorganic compounds.
• Their ability to release peroxo ligands electrochemically suggests potential in redox catalysis.
• These compounds show promise as efficient oxo-transfer agents in chemical reactions.