Small molecule activation by multimetallic uranium complexes supported by siloxide ligands.

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Uranium Chemistry

Background:

• Uranium compounds often exhibit high reactivity, posing challenges for synthesis and stabilization.
• The tris-tert-butoxysiloxide ligand offers unique steric and electronic properties for stabilizing metal complexes.

Purpose of the Study:

• To survey the synthesis and reactivity of uranium complexes supported by the tris-tert-butoxysiloxide ligand.
• To explore the stabilization of reactive uranium species and their interactions with small molecules.

Main Methods:

• Synthesis of uranium complexes featuring the tris-tert-butoxysiloxide ligand.
• Characterization of homo- and heteropolymetallic uranium complexes.
• Investigation of reactivity towards small molecules (CO2, CS2, chalcogens, azides).

Main Results:

• The tris-tert-butoxysiloxide ligand effectively stabilizes highly reactive uranium complexes.
• Unusual high reactivity of these complexes towards small molecules was observed.
• Isolation of dinuclear nitride and oxide bridged uranium complexes in various oxidation states was achieved.
• Trapping of alkali ions within nitride or oxide complexes led to unprecedented reductions and functionalizations of N2, CO, CO2, and H2.

Conclusions:

• The tris-tert-butoxysiloxide ligand is a versatile tool for stabilizing reactive uranium species.
• These stabilized complexes exhibit novel reactivity, including ligand and metal-based reductions and functionalizations.
• This work opens new avenues for uranium chemistry and small molecule activation.