title: A new tripodal ligand system with steric and electronic modularity for uranium coordination chemistry.
abstract: The synthesis of a potentially redox active tripodal ligand containing a tris(aryloxide) functionalized mesitylene anchor, (((tBu)ArOH)(3)mes) (1), and its metalation with low-valent uranium to form [(((tBu)ArO)(3)mes)U] (1-U) is reported. The results from characterization by X-ray crystallography, spectroscopic studies, and computational analysis, as well as initial reactivity studies, support a +3 uranium oxidation state. Comparison to the previously synthesized complex, [(((tBu)ArO)(3)tacn)U] (2-U), featuring the redox-innocent triazacyclononane anchor reveals that changing the anchor from the flexible triazacyclononane to a rigid mesityl fragment increases the structural flexibility of the aryloxide substituents in complexes of 1. The synthesis and crystal structures of uranium(IV) amide complexes of 1-U and 2-U are discussed.
authors.affiliation: Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander University of Erlangen-Nuremberg, Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Bart
authors.forename: Frank W
authors.initials: FW
authors.lastname: Heinemann
authors.forename: Christian
authors.initials: C
authors.lastname: Anthon
authors.forename: Christina
authors.initials: C
authors.lastname: Hauser
authors.forename: Karsten
authors.initials: K
authors.lastname: Meyer