Reactivity of a dithorium oxo complex from adventitious water

Area of Science:

• Organometallic Chemistry
• Thorium Chemistry
• Coordination Chemistry

Background:

• Thorium complexes, such as [ThCl4(DME)2], are precursors in organometallic synthesis.
• The controlled introduction of water can lead to unique structural motifs in metal complexes.
• Understanding the reactivity of thorium complexes is crucial for developing new catalytic and material applications.

Purpose of the Study:

• To synthesize and characterize a novel bridging oxo complex of thorium.
• To investigate the reactivity of the synthesized oxo complex with various electrophilic and nucleophilic reagents.
• To explore the structural diversity of thorium organometallic compounds.

Main Methods:

• Synthesis of [{(C5Me5)2ThCl}2(μ-O)] from [ThCl4(DME)2] and [K(C5Me5)] in the presence of adventitious water.
• Alternative synthesis of the oxo complex from [(C5Me5)2ThCl2] and degassed water.
• Reactivity studies using reagents such as Me3SiCl, AlCl3, MeMgCl, and PhN(H)N(H)Ph.
• Characterization of all synthesized complexes using spectroscopic (e.g., NMR) and X-ray crystallographic methods.

Main Results:

• The bridging oxo complex [{(C5Me5)2ThCl}2(μ-O)] (1) was successfully synthesized and characterized.
• Reactions of complex 1 with Me3SiCl and AlCl3 quantitatively yielded [(C5Me5)2ThCl2].
• Treatment of complex 1 with MeMgCl afforded the dimethyl complex [{(C5Me5)2ThMe}2(μ-O)] (2).
• Further reaction of complex 2 with PhN(H)N(H)Ph produced complex [{(C5Me5)2Th(PhNN(H)Ph)}2(μ-O)] (3).

Conclusions:

• Adventitious water is a key reagent in the formation of bridging oxo thorium complexes.
• The synthesized oxo complex serves as a versatile precursor for further functionalization.
• The study demonstrates the rich reactivity of thorium organometallic compounds, leading to diverse structural outcomes.