Thorium amidates function as single-source molecular precursors for thorium dioxide.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• Thorium dioxide (ThO2) is a material with significant applications in nuclear energy and catalysis.
• Developing efficient and controlled synthesis methods for high-purity ThO2 is crucial.
• Single-source molecular precursors offer a pathway to precise material fabrication.

Purpose of the Study:

• To synthesize novel homoleptic thorium(IV) amidate complexes.
• To evaluate these complexes as single-source molecular precursors for thorium dioxide.
• To investigate the influence of ligand substituents on precursor properties and resulting ThO2 characteristics.

Main Methods:

• Synthesis of four homoleptic thorium(IV) amidate complexes.
• Sublimation of complexes at atmospheric pressure to assess volatility.
• Thermal decomposition (pyrolysis) of precursors to form thorium dioxide.
• Characterization of ThO2 purity and crystallinity using analytical techniques.

Main Results:

• Successfully synthesized four homoleptic thorium(IV) amidate complexes.
• Demonstrated atmospheric pressure sublimation for all complexes, with volatility dependent on ligand substituents.
• Achieved ThO2 formation via alkene elimination without an external oxygen source.
• ThO2 derived from C-alkyl amidate precursors exhibited superior purity and crystallinity compared to ThO2 from C-aryl amidates.

Conclusions:

• Homoleptic thorium(IV) amidate complexes are effective single-source precursors for thorium dioxide.
• Ligand design significantly impacts precursor volatility and thermal stability.
• C-alkyl amidate precursors are advantageous for producing high-purity, crystalline ThO2.