Alkoxide and Aryloxide Derivatives of a (Triamidoamine)uranium Complex.
The (triamidoamine)uranium chloride complex [{U(NN(3))(&mgr;-Cl)}(2)] [NN(3) = N(CH(2)CH(2)NSiMe(3))(3)] reacts with alkali metal alkoxides and aryloxides to give a range of complexes [U(NN(3))(OR)] (R = Bu(t), t-C(4)F(9), Ph, 2,6-Bu(t)(2)-4-MeC(6)H(2)). Crystallographic investigations (including the molecular structure of the perfluoro-tert-butoxido derivative [U(NN(3))(O-t-C(4)F(9))]), molecular weight determinations, and NMR spectroscopic data are consistent with these molecules being monomeric with a 3-fold symmetric arrangement of the triamidoamine fragment. The three turquoise ate complexes [U(NN(3))(OR)(OR')Li(THF)(n)()] (R, R' = Bu(t) or Ph), are prepared by reaction of the corresponding uranium alkoxides with lithium phenoxide or tert-butoxide. The complex with R = Ph, R' = Bu(t), n = 1 is shown by X-ray crystallography to have a capped trigonal bipyramidal structure. A lithium atom is incorporated into the ligand sphere by coordination to an amido nitrogen and a tert-butoxido oxygen. The mixed alkoxide ate complex [U(NN(3))(OBu(t))(OPh)Li(THF)] gives only [U(NN(3))(OBu(t))] on heating in vacuo. The one-electron oxidation of these ate complexes to the three neutral pentavalent compounds [U(NN(3))(OR)(OR')] (R, R' = Bu(t) or Ph) has been characterized by cyclic voltammetric studies and performed on the chemical scale by reaction with [FeCp(2)][PF(6)].
Roussel
Paul
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The School of Chemistry, Physics and Environmental Science, University of Sussex, Falmer, Brighton BN1 9QJ, U.K., and Company Research Laboratory, BNFL, Springfields Works, Salwick, Preston PR4 0XJ, U.K.
Hitchcock
Peter B.
PB
Tinker
Nigel D.
ND
Scott
Peter
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