Reactivity of Methyl Groups in Actinide Metallocene Amidinate and Triazenido Complexes with Silver and Copper Salts

The effect of the heteroleptic ligand sets {(C(5)Me(5))(2)[(i)PrNC(Me)N(i)Pr]}(3-) and {(C(5)Me(5))(2)[(Me)-NNN(Ad)]}(3-) on actinide-carbon bond reactivity has been evaluated by examining the monomethyl actinide metallocene amidinate complexes (C(5)Me(5))(2)[(i)Pr-NC(Me)N(i)Pr-k(2)N,N']AnMe(An = U, 1; Th, 2) and the triazenido complex (C(5)Me(5))(2)[(Me)NNN(Ad)-k(2) N(1.3)]U Me, 3. This has led to a facile method to convert methyl groups in U(4+) and Th (4+) complexes to halide and pseudo-halide ligands. Complexes 1 and 3 react with AgOSO(2),CF(3) (AgOTf) to produce (C(5)Me(5))(2)[(i)PrNC(Me)N(i)Pr-k(2) N,N(1)]U(OTf), 4, and (C(5)Me(5))(2)[(Mc)NNN(Ad)-k(2) N(1.3)]U(OTf), 5, respectively. The methyl complexes are also reactive with copper reagents, as demonstrated by the reactions of Cul with 1 and 2 to make(C(5)Me(5))(2)[(i)PrNC(Me)N(i)Pr-k(2)N,N']UI,6, and(C(5)Me(5))2[(i)PrNC(Me)N(i)Pr-k(2) N,N']Th1,7, respectively. Similarly, reactions of CuBr with 1 and 3 generate (C(5)Me(5))2([)[(i)PrNC(Me)N(i)Pr-k(2)N,N']UBr, 8, and (C(5)MC(5))(2)[(Me)NNN(Ad)-K(2)N(1.3)] UBr, 9, respectively. These triflate and halide complexes are good precursors to other complexes with these ligand sets, as exemplified by their reactions with NaN(3), which produce (C(5)Me(5))(2)[(i)PrNC(Me)N(i)Pr-k(2) N,N']U(N(3)), 10, and (C(5)Me(5))(2)[(Me)NNN(Ad)-k(2) N(1.3)]U(N(3)), 11, respectively. However, the reactions of 4 and 6 with LiCH(2)SiMe(3) lead to reduction and the formation of the trivalent uranium heteroleptic metallocene (C(5)Me(5))2[(i)PrNC(Me)N(i)Pr-k(2)-N,N']U, 12. LiCH(2)SiMe(3) does not cause reduction with the triazenido ligand set, and the monoalkyl complex (C(5)Me(5))(2)[(Me)NNN(Ad)-k(2)N(1.3)]U(CH(2)SiMe(3)), 13, can be isolated.