"Oxidative addition" of halogens to uranium(IV) bis(amidophenolate) complexes
Ellen M Matson1, Stacey R Opperwall, Phillip E Fanwick
1H. C. Brown Laboratory, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
Inorganic Chemistry
|June 6, 2013
Summary
New uranium(IV) complexes featuring redox-active amidophenolate ligands were synthesized. These complexes undergo oxidative addition with PhICl2, forming uranium(IV) dichloride dimers, and react with iodine to yield new uranium compounds.
Area of Science:
- Organometallic Chemistry
- Uranium Chemistry
- Coordination Chemistry
Background:
- Uranium complexes with redox-active ligands are of interest for understanding fundamental electronic structures and reactivity.
- Amidophenolate ligands offer tunable steric and electronic properties for stabilizing metal centers.
Purpose of the Study:
- To synthesize and characterize novel uranium(IV) complexes supported by redox-active amidophenolate ligands.
- To investigate the reactivity of these uranium complexes with electrophilic halogenating agents like PhICl2 and I2.
Main Methods:
- Synthesis of uranium(IV) complexes via salt metathesis reactions.
- Characterization using 1H NMR spectroscopy, electronic absorption spectroscopy, and X-ray crystallography.
- Investigation of reactivity through oxidative addition and halogenation reactions.
Main Results:
- Successful synthesis of three U(IV) complexes, ((R)ap)2U(THF)2, with varying R groups (t-Bu, Ad, dipp).
- Oxidative addition of PhICl2 yielded uranium(IV) dichloride dimers, [((R)isq)2UCl]2(μ(2)-Cl)2.
- Selective reaction of iodine with one complex formed ((tBu)isq)2UI2(THF), while others decomposed.
Conclusions:
- The redox-active amidophenolate ligand effectively supports U(IV) oxidation state and influences reactivity.
- The synthesized uranium complexes exhibit distinct reactivity patterns towards electrophilic halogenating agents.
- Structural characterization provides insights into the coordination environment and bonding in these uranium compounds.
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