N-Aryloxide-Amidinate Thorium Complexes.

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Actinide Chemistry

Background:

• The development of versatile ligands is crucial for exploring the coordination chemistry of actinides.
• N-aryloxide-amidine ligands offer a unique combination of donor atoms for metal complexation.

Purpose of the Study:

• To synthesize and characterize novel actinide complexes using an N-aryloxide-amidine ligand.
• To investigate the structural diversity and electronic properties of thorium complexes derived from this ligand.

Main Methods:

• Synthesis of an N-aryloxide-amidine ligand ([ONNO]).
• Reaction of the ligand with thorium tetrachloride (ThCl4(DME)2) to form dimer complex 2.
• Further functionalization of complex 2 with KCp* to yield complex 4.
• Redox studies involving complex 2 and bipyridine with KC8 to generate radical and dianionic species (5 and 6).

Main Results:

• The N-aryloxide-amidine ligand successfully formed dimeric thorium complexes (2 and 4).
• Complex 2 exhibited bridging coordination of the phenoxide arms to different thorium centers.
• Complex 4 showed chelation of both phenoxide arms to a single thorium center.
• Redox manipulation of complex 2 in the presence of bipyridine led to the formation of radical and dianionic thorium-bipyridyl complexes (5 and 6).

Conclusions:

• The [ONNO] ligand is effective in stabilizing diverse thorium coordination environments.
• The ligand enables the formation of structurally distinct thorium complexes with tunable electronic properties.
• This work expands the scope of ligand design for actinide chemistry and redox manipulation.