Multinuclear Er-Containing Polyoxometalate Macrocycle Based on Seleno-Bismutho-Tungstate Fragments.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Catalysis

Background:

• Polyoxometalates (POMs) are versatile nanoscale materials with diverse structures and applications.
• Lanthanide-containing POMs are of interest for their unique magnetic and optical properties.
• Developing novel POM architectures with complex heteroatom incorporation remains a challenge.

Purpose of the Study:

• To synthesize and characterize a novel high-nuclearity lanthanide-containing macrocyclic polyoxometalate.
• To explore the catalytic activity of the new compound in selective oxidation reactions.

Main Methods:

• One-pot assembly reaction using sodium tungstate, erbium nitrate, bismuth nitrate, sodium selenite, and dimethylamine hydrochloride.
• Structural characterization via X-ray diffraction and other spectroscopic techniques.
• Evaluation of catalytic performance in the selective oxidation of sulfides.

Main Results:

• Successful synthesis of a novel macrocyclic seleno-bismutho-tungstate incorporating high nuclearity erbium, denoted as [H2N(CH3)2]14Cs6H28[Er4(H2O)8{Er3(H2O)9(SeBiW12O45)2}4]·127H2O (1).
• The polyoxoanion features an unprecedented octameric assembly with a novel SeBiW12O45 fragment templated by both selenium and bismuth heteroatoms.
• Compound 1 exhibits high efficiency and selectivity in catalyzing the oxidation of various sulfides.

Conclusions:

• This work reports the first example of a lanthanide-containing macrocyclic seleno-bismutho-tungstate.
• The synthesized compound represents the largest bismutho-seleno-tungstate discovered to date.
• The compound shows significant promise as an efficient catalyst for selective sulfide oxidation.