Tuning Reactivity and Electronic Properties through Ligand Reorganization within a Cerium Heterobimetallic Framework

Abstract

Cerium compounds have played vital roles in organic, inorganic, and materials chemistry due to their reversible redox chemistry between trivalent and tetravalent oxidation states. However, attempts to rationally access molecular cerium complexes in both oxidation states have been frustrated by unpredictable reactivity in cerium(III) oxidation chemistry. Such oxidation reactions are limited by steric saturation at the metal ion, which can result in high energy activation barriers for electron transfer. An alternative approach has been realized using a rare earth/alkali metal/1,1'-BINOLate (REMB) heterobimetallic framework, which uses redox-inactive metals within the secondary coordination sphere to control ligand reorganization. The rational synthesis of functionalized cerium(IV) products and a mechanistic examination of the role of ligand reorganization in cerium(III) oxidation are presented.

Ceric Ammonium Nitrate and Ceric Ammonium Chloride as Precursors for Ceric Siloxides: Ammonia and Ammonium Inclusion

“…The data obtained from the measurements of complex 5 , 5(py) and 6 in CH 2 Cl 2 solvent revealed less separated reductive and oxidative electrochemical happenings (Figure ). Rigid and confined ligand environments are known to enhance electrochemical reversibility , …”

Proton-Coupled Electron Transfer in the Reduction of Arenes by SmI2–Water Complexes

“…33 In the present case, anthracene would have to displace water in the second coordination sphere leading to a change in the mechanism where water displacement is likely rate-limiting. Although the majority of the work described above is focused on concentrations of water typically employed in reductions by SmI 2 , we believe it is useful to consider why higher concentrations of water lead to saturation and eventual inverse order of the proton donor.…”

Structural variation in cerium aryloxide complexes templated by hemilabile K+–amine interactions

“…3). 10 We expected the bulky aryl oxides would confer slower electron transfer rates at the cerium metal center, resulting in larger peak separation between the cathodic and the anodic waves. 10 We expected the bulky aryl oxides would confer slower electron transfer rates at the cerium metal center, resulting in larger peak separation between the cathodic and the anodic waves.…”