The Effect of the Secondary Coordination Sphere on the Stabilities of Cerium(III) and Cerium(IV) Coordination Complexes

The lanthanides, the elements from La–Lu, have intrinsic properties that make them desirable components in many technological applications as well as useful catalysts. However, lanthanides can form unpredictable solid state and solution structures due to their ionic, non-directional, and kinetically labile bonds with ligands, which hampers the development of structure-function relationships. To enhance the stability of the lanthanide bonds, the use of the secondary coordination sphere about lanthanide complexes, including alkali metal cations lithium, sodium, and potassium, as well as hydrogen bonding guanidinium cations, as a framework to guide lanthanide-ligand bonding interactions was studied. This work can be applied to lanthanide coordination and redox chemistries.