Tetravalent Cerium Alkyl and Benzyl Complexes

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Cerium Chemistry

Background:

• High-valent cerium (Ce4+) is a strong oxidant, typically incompatible with reducing alkyl or benzyl ligands.
• The synthesis of stable tetravalent cerium complexes with these ligands has remained a significant challenge.

Purpose of the Study:

• To report the first synthesis and isolation of tetravalent cerium alkyl and benzyl complexes.
• To characterize these novel organocerium compounds using advanced spectroscopic and analytical techniques.

Main Methods:

• Synthesis of a tetravalent cerium monoiodide precursor, [Ce4+I(NP(tert-butyl)3)3].
• Preparation of alkyl (neopentyl) and benzyl complexes using the precursor.
• Characterization via single-crystal X-ray diffraction (XRD), NMR, UV-vis-NIR spectroscopy, cyclic voltammetry, and DFT studies.

Main Results:

• Successfully synthesized and isolated the first tetravalent cerium neopentyl and benzyl complexes.
• The complexes are supported by the tri-tert-butyl imidophosphorane ligand, [NP(tBu)3]1-.
• Detailed structural and bonding analyses were performed, confirming the unprecedented nature of these compounds.

Conclusions:

• Demonstrated the feasibility of stabilizing high-valent cerium with alkyl and benzyl ligands using the imidophosphorane support.
• These findings expand the scope of organocerium chemistry and high-valent metal complexes.
• The characterized complexes offer new platforms for exploring reactivity and applications of cerium.