Fe^III ₄₈ -Containing 96-Tungsto-16-Phosphate: Synthesis, Structure, Magnetism and Electrochemistry

Area of Science:

• Inorganic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Polyoxometalates (POMs) are versatile inorganic clusters with diverse applications.
• Developing POMs with high nuclearity, particularly those containing transition metals like iron, is an active area of research.
• Existing POMs often have limitations in terms of metal center density and structural complexity.

Purpose of the Study:

• To synthesize and structurally characterize a novel, high-nuclearity iron-containing polyoxometalate.
• To explore a new synthetic route for complex POMs using a one-pot reaction.
• To investigate the structural and magnetic properties of the newly formed Fe48 polyanion.

Main Methods:

• One-pot synthesis involving an {Fe22} coordination complex and a {P2W12} POM precursor.
• Single-crystal X-ray diffraction (XRD) for structural determination.
• Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), magnetic studies, and electrochemical studies for characterization.

Main Results:

• Successful synthesis and structural characterization of the 48-Fe(III)-containing 96-tungsto-16-phosphate, [Fe48(OH)76(H2O)16(HP2W12O48)8]36- (Fe48).
• The Fe48 polyanion features a macrocyclic assembly composed of eight {Fe6P2W12} units, establishing a new record for iron centers in a POM.
• The synthesis was achieved via a simple one-pot reaction in water.

Conclusions:

• The Fe48 polyanion represents a significant advancement in the field of high-nuclearity polyoxometalates.
• The developed one-pot synthetic strategy offers a facile route to complex POM architectures.
• The structural and magnetic properties of Fe48 warrant further investigation for potential applications.