Halide effects in the synthesis of mixed uranium(IV) aryloxide-halide compounds
- Los Alamos National Lab., NM (United States)
Several uranium(IV) aryloxide and mixed aryloxide-halide compounds of the formula UX{sub 4{minus}z}(OAr){sub z} (X = Cl, Br, I; OAr = 2,6-di-tert-butylphenoxide; z = 2, 3, 4) have been prepared by the reaction of KOAr with the appropriate uranium tetrahalide in tetrahydrofuran (THF). The complex UI{sub 4}(CH{sub 3}CN){sub 4} reacts with 2 equiv of KOAr in THF to yield the compound I{sub 2}U(OAr){sub 2} (1). The utility of this reaction is limited by the instability of UI{sub 4}(CH{sub 3}CN){sub 4} in THF, however, and isolated yields of the THF adduct of 1 do not exceed 50%. In contrast, UBr{sub 4}(CH{sub 3}CN){sub 4} is stable in THF solution and reacts with 2 equiv of KOAr to yield the dibromide, Br{sub 2}U(OAr){sub 2}-(THF) (4{center_dot}THF), in 77% yield. Under identical reaction conditions, UCl{sub 4} reacts to yield the complex [K(THF){sub 4}]-[UCl{sub 3}(OAr){sub 2}] (5) in 68% yield. The uranium center in compound 5 is coordinated by two trans aryloxide ligands and three chloride ligands in a trigonal bipyramidal arrangement. Two chloride ligands of each unit are also coordinated to a potassium ion, forming an infinite chain in the lattice. Compounds 1 and 5 will further react with 1 equiv of KOAr to yield the compounds XU(OAr){sub 3} (2, X = I; 6, X = Cl). Both UI{sub 4}(CH{sub 3}CN){sub 4} and UCl{sub 4} will react with a 4.2 equiv of KOAr to yield the previously characterized compound U(OAr){sub 4} (3). The stability of the mixed aryloxide-halide uranium complexes toward ligand redistribution reactions has been investigated.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- OSTI ID:
- 653427
- Journal Information:
- Inorganic Chemistry, Vol. 37, Issue 16; Other Information: PBD: 10 Aug 1998
- Country of Publication:
- United States
- Language:
- English
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