Reaction Chemistry of the U³⁺ Metallocene Amidinate (C₅Me₅)₂[ⁱPrNC(Me)NⁱPr]U Including the Isolation of a Uranium Complex of a Monodentate Acetate

Abstract

The reductive chemistry of U(3+) in the metallocene amidinate coordination environment of (C(5)Me(5))(2)[(i)PrNC(Me)N(i)Pr-kappa(2)N,N']U, 1, has been explored. Two equivalents of 1 react with PhSSPh and 2,2'-dithiopyridine (pySSpy) to produce (C(5)Me(5))(2)[(i)PrNC(Me)N(i)Pr-kappa(2)N,N']U(SPh), 2, and (C(5)Me(5))(2)[(i)PrNC(Me)N(i)Pr-kappa(2)N,N']U(Spy), 3, respectively. Complexes 2 and 3 can also be synthesized through insertion of (i)PrN horizontal lineC horizontal lineN(i)Pr into the methyl group in (C(5)Me(5))(2)UMe(SPh) and (C(5)Me(5))(2)UMe(Spy), 4, respectively. Complex 1 readily reduces the Cu(1+) reagents, CuBr, CuI, and CuO(2)CMe, to produce the corresponding (C(5)Me(5))(2)[(i)PrNC(Me)N(i)Pr-kappa(2)N,N']UX complexes (X = Br, 5; I, 6; O(2)CMe, 7). X-ray crystallography established complex 7 as the first f element complex containing a monodentate acetate anion. Complex 7 can also be obtained by reaction of (C(5)Me(5))(2)[(i)PrNC(Me)N(i)Pr-kappa(2)N,N']UMe with CO(2) at 80 psi. In contrast to the reactions above, 1 reduces TlC(5)H(5) with the unusual loss of (C(5)Me(5))(-) to form (C(5)Me(5))(C(5)H(5))(2)[(i)PrNC(Me)N(i)Pr-kappa(2)N,N']U, 8.

New Benzylpotassium Reagents and Their Utility for the Synthesis of Homoleptic Uranium(IV) Benzyl Derivatives

“…The nitrogen atoms of the pyridine rings are coordinated, with U−N interactions averaging 2.452 Å, as expected for dative interactions. The U− N distances are on the order of those displayed in Cp* 2 UMe(Spy) (2.448 Å) 22 (py = pyridine) and Cp* 2 U(η 2 -picoline)CH 3 (2.394(3) Å). 23 The coordination mode noted for 2-o-Picolyl is similar to that previously observed by Rothwell for the thorium(IV) species Th(OAr′) 2 (CH 2 -py-6-Me) 2 (Ar′ = 2,6-di-tert-butylphenyl).…”

Diazoalkane Reduction for the Synthesis of Uranium Hydrazonido Complexes

“…Following refinement of the data, compound 4 is assigned as the uranium(IV) metallacycle Tp* 2 U-N(N=CHSiMe 3 )CH=CPh (4) (Figure 1, Table 1), which features an eight-coordinate uranium atom in a distorted square-antiprismatic geometry. [19,[45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62] This is most likely due to increased s character at the U-C44 bond as a result of multiple bonding at the adjacent carbon-carbon bond (C44-C45). The resulting structure of complex 4 has a U1-N41 bond length of 2.348(6) Å, indicative of a uranium(IV)-nitrogen(amide) bond.…”

Applications of boroxide ligands in supporting small molecule activation by U(iii) and U(iv) complexes

“…Since then, several examples of insertion of carbodiimides into metal-ligand σ-bonds have been reported, [74][75][76][77] as well as further reactivity towards small molecules with these ligands. [78][79][80] Moreover, reactions of carbodiimides have also led to the formation of metallacycles that have unique structural properties and possible applications in catalysis. [81][82][83][84] ð2Þ…”