Effect of -element complexation on the radiolysis of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]).

A systematic study of the impact on the chemical reactivity of the oxidising -dodecane radical cation (RH˙) with -element complexed 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) has been undertaken utilizing time-resolved electron pulse radiolysis/transient absorption spectroscopy and high-level quantum mechanical calculations. Lanthanide ion complexed species, [Ln((HEH[EHP]))], exhibited vastly increased reactivity (over 10× faster) in comparison to the non-complexed ligand in -dodecane solvent, whose rate coefficient was = (4.66 ± 0.

Metal-Ligand Redox Cooperativity in Cerium Amine-/Amido-Phenolate-Type Complexes.

The synthesis and characterization of two cerium complexes of redox-active amine/amido-phenolate-type ligands are reported. A tripodal framework comprising the tris(2-(3',5'-di--butyl-2'-hydroxyphenyl)amino-phenyl) amine (HClamp) proligand was synthesized for comparison of its cerium complex with a potassium-cerium heterobimetallic complex of the 4,6-di--butyl-2-[(2,6-diisopropylphenyl)imino]quinone (ap) proligand. Structural studies indicate differences in the cerium(III) cation coordination spheres, where Ce(CHCN)(HClamp) () exhibits shorter Ce-O distances and longer Ce-N bond distances compared to the analogous distances in K(THF)Ce(ap) (), due to the gross structural differences between the systems.

Actinide-Oxygen Multiple Bonds from Air: Synthesis and Characterization of a Thorium Oxo Supported by Redox-Active Ligands.

The first non-uranyl, f-element oxo complex synthesized from dioxygen in dry air is presented in this work. The synthesis was accomplished by treating the redox-active thorium amidophenolate complex, [Th(ap)][K(15--5)] (), with dioxygen in dry air, forming a rare terminal thorium oxo, [O═Th(isq)(ap)][K(15--5)] (). Compound was regenerated by treating with potassium graphite.

Elucidation of Thorium Redox-Active Ligand Complexes: Evidence for a Thorium-Tri(radical) Species.

A series of thorium(IV) complexes featuring the redox-active 4,6-di--butyl--(2,6-di-isopropylphenyl)--iminobenzoquinone (iq) ligand family have been synthesized and characterized. The neutral iminoquinone ligand was used to generate Th(iq)Cl(dme) () and Th(iq)Cl (), both of which show dative bonds between the thorium(IV) ion and the ligands. One electron reduction of the ligand forms the unique tris(iminosemiquinone) complex, Th(isq)Cl (), which features a radical in each ligand.