571146-08-2Relevant articles and documents
Triamidotriazacyclononane complexes of group 3 metals. Synthesis and crystal structures
Monteiro, Bernardo,Roitershtein, Dmitrii,Ferreira, Humberto,Ascenso, Jose R.,Martins, Ana M.,Domingos, Angela,Marques, Noemia
, p. 4223 - 4231 (2008/10/08)
Reaction of yttrium and lanthanide trichlorides (Ln = La, Eu, Yb) with 1 equiv of the trisodium salt of 1,4,7-tris(dimethylsilylaniline)-1,4,7-triazacyclononane (Na3[(SiMe2NPh)3-tacn](THF)2) gives good yields of the compounds [M{(SiMe2NPh)3-tacn}] (M = Y (1), Eu (3), Yb (4)) and [La{(SiMe2NPh)3-tacn}(THF)] (2). Reduction of 3 with Na/Hg followed by recrystallization in the presence of diglyme yielded crystals of [Eu{(SiMe2NPh)3-tacn}][Na(diglyme)2] (5). Synthesis of the uranium(III) complex [U{(SiMe2NPh)3-tacn}] (6) is achieved by reaction of 1 equiv of Na3[(SiMe2NPh)3-tacn](THF)2 with uranium triiodide. The U(IV) complexes, [U{(SiMe2NPh)3-tacn}X] (X = Cl (7); I (8)), were prepared via oxidation of 6 with benzyl chloride or I2, but salt metathesis from UCl4 provided a higher yield route for 7. The solid-state structures of 1-7 were determined by single-crystal x-ray diffraction. The ligand [(SiMe2NPh)3-tacn] generates a trigonal prismatic coordination environment for the metal center in the neutral complexes 1, 3, 4, and 6 and the ionic 5. In 2 the six nitrogen atoms of the ligand are in a trigonal prismatic configuration with the oxygen atom of the THF capping one of the triangular faces of the trigonal prism. In 7 the coordination geometry around the uranium atom is best described as bicapped trigonal bipyramidal.
