Cerium(III) Azolate Promoted CO 2 Insertion
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide A series of sandwich cerium azolates (pyrazolates, triazolates, tetrazolates) has been synthesized via salt-metathesis (cerous precursor: [Cp* 2 CeCl 2 K(thf)] n; Cp* = C 5 Me 5 ) and protonolysis protocols (cerous precursors: Cp* 2 Ce[N(SiHMe 2 ) 2 ] or Cp* 2 Ce[N(SiMe 3 ) 2 ]) and their carboxophilicity has been probed. The sandwich and half-sandwich complexes Cp* 2 Ce(pz Me,Me ) and Cp*Ce(pz Me,Me ) 2 (thf) 2 show exhaustive CO 2 insertion into the pyrazolato moieties, which leads to bis(carbamato)-bridged dimeric complexes. Complex Cp* 2 Ce(pz Ph,Ph ), featuring the sterically more demanding and less nucleophilic diphenylpyrazolato ligand inserts only one molecule CO 2 per two metal centers, forming the asymmetrically bridged complex Cp* 2 Ce(μ-pz Ph,Ph ·CO 2 )CeCp* 2 (pz Ph,Ph ). The triazolato derivatives Cp* 2 Ce(tz Me,Me )(dmap) and Cp* 2 Ce(tz Ph,Ph ) indicate CO 2 insertion only for the DMAP-free complex. Utilizing the nitrogen-richer 5-phenyltetrazole resulted in the formation of the trimer [Cp* 2 Ce(tet Ph )] 3, which does not insert CO 2 at ambient temperature. The absorption and electrochemical properties of the compounds were investigated and their catalytic activity in the cycloaddition of CO 2 and propylene oxide was examined.
Source: Inorganic Chemistry
Institution: University of Tübingen
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Funder: Vector Stiftung
Award: G485222300
OpenAlex ID: W4415927920