Oxidation Chemistry of a Uranium(III) Aryloxide

Production and collision‐induced dissociation of gas‐phase, water‐ and alcohol‐coordinated uranyl complexes containing halide or perchlorate anions

“…In addition, an inductive effect due to the alkyl substituents might increase the strength of the interaction between UO 2 and the alkoxide species generated after proton transfer and thus be a driving force for the elimination of the neutral acid during CID. The preference for formation of alkoxide species would be consistent with previously reported tendencies for lanthanide and actinide species to form alkoxide complexes,12–14 and calculations suggest that replacing OH bonds with OCH 3 within a uranyl complex increases the binding energy to the uranyl ion 6. Our hypothesis was that the composite influence of increased acidity and electron donation by the alkoxides would manifest itself in an increased tendency to eliminate HCl, HBr, HI or HClO 4 at early CID stages (MS/MS and MS 3 ) particularly when compared to CID of the complexes containing H 2 O ligands.…”

Synthesis of Actinide Fluoride Complexes Using Trimethyltin Fluoride as a Mild and Selective Fluorinating Reagent

“…Insoluble solids were collected on a coarse‐porosity fritted filter, washed with (Me 3 Si) 2 O (0.5 mL), and dried under reduced pressure to give U(F)(O‐2,6‐ t Bu 2 C 6 H 3 ) 3 ( 8 ) as a yellow solid (0.040 g, 0.046 mmol, 54 %). The 1 H NMR spectrum collected in [D 6 ]benzene was consistent with data previously reported for complex 8 . 1 H NMR ([D 6 ]benzene, 298 K): δ = 15.97 (s, 6 H, ν 1/2 = 43 Hz, m ‐Ar– H ), 12.43 (s, 3 H, ν 1/2 = 28 Hz, p ‐Ar– H ), –4.54 (s, 54 H, ν 1/2 = 62 Hz, C Me 3 ) ppm.…”

“…Reaction of Me 3 SnF with the uranium(IV) aryloxide–chloride complex, (C 5 Me 5 ) 2 U(Cl)(O‐2,6‐ i Pr 2 C 6 H 3 ) ( 5 ), proceeds smoothly at room temperature to afford Me 3 SnCl and the corresponding uranium(IV) fluoride complex (C 5 Me 5 ) 2 U(F)(O‐2,6‐ i Pr 2 C 6 H 3 ) ( 6 ) in 93 % yield [Equation (2)]. Likewise, treatment of the uranium(IV) tris(aryloxide) iodide and tris(amide) chloride complexes, U(I)(O‐2,6‐ t Bu 2 C 6 H 3 ) 3 ( 7 ) and U(Cl)[N(SiMe 3 ) 2 ] 3 ( 9 ), with Me 3 SnF forms U(F)(O‐2,6‐ t Bu 2 C 6 H 3 ) 3 ( 8 ) and U(F)[N(SiMe 3 ) 2 ] 3 ( 10 ) in 53 % and 93 % yields, respectively [Equations (3) and (4)]. Previously, all three complexes, 6 , 8 , and 10 , were prepared by redox or fluoride‐atom abstraction oxidative methods.…”

Dinuclear uranium complexation and manipulation using robust tetraaryloxides

“…In collaboration with Love, we recently reported the use of expanded Pacman-shaped N-donor macrocycles to combine two U III centres at a distance suitable for trapping a di-or triatomic fragment, but have been unable as yet to isolate complexes in which no X-ligand is coordinated between the two U centres. 10,11 Recognising the strength of the U-aryloxide bond in a range of U oxidation states, 7,[12][13][14][15][16] we have developed a two-hour, one-pot, large-scale synthesis of three closely related analogues of a known arene-bridged tetraphenol 17 in order to isolate and study the first O-donor compounds containing two discrete U III or U IV centres in a single molecule, in geometries pre-organised for small molecule binding. The three phenols used here are H 4 L P and H 4 L M , and phenylsubstituted H 4 L P *, Fig.…”