17594-47-7Relevant articles and documents
Reactivity of mixed-metal BaCu and BaY β-diketonatoalkoxides with Lewis bases.
Labrize, Florence,Hubert-Pfalzgraf, Liliane G.,Vaissermann, Jacqueline,Knobler, Carolyn B.
, p. 577 - 589 (2008/10/08)
Reactions involving Y(Thd)3 and Cu(thd)2 with barium tert-butoxide or 2-dimethylamino-2-propoxide were investigated. The mixed-metal complexes [YBa3(OBu1)6(thd)3] (1) and [BaCu(OBu1)2(thd)2]m (3) (thdH = 2.2.6.6-tetramethylheptane-3,5-dione) were isolated in hexane. Dissolution of 3 in Et2O or THF afforded [Cu3(OBu1)3(thd)3] (4) and [Cu(thd)2(OBu1)2(THF)2] (5), respectively, while [Ba(thd)2(TMEDA)2] (2) was obtained in the presence of N′,N′-tetramethylenediamine. Dissolution of 1 in THF afforded a THF adduct (1a) giving 1 by sublimation at 190°C 10 Torr. By contrast, the reaction between the barium aminoalkoxide and Y(thd)2 in hexane proceeded directly to the formation of homometallic compounds, whereas with Cu(thd)2 the mixed-metal compound {Ba2Cu [OCHMeCH2NMe2]2(thd)2(Pr 1OH)2} (6) was obtained by crystallization from Pr1OH. All compounds were characterized by elemental analysis. IR. 1H NMR, ESR and TGA for the copper species. Compounds 2, 4 and 6 were characterized by single-crystal X-ray diffraction. The [Ba(thd)2(TMEDA)2] adduct is monomeric. The structures of 4 and 6 consist of triangular aggregates with Cu3(μ3-OBu1)2(μ-OBu 1)(thd)3 and Ba2Cu(μ3,η2-OCHMe CH2NMe2)2(μ,η2-thd) 2(η2-thd)2(Pr1OH)2 cores, respectively. Compound 4 exhibits one square planar and two square pyramidal copper centres. The Cu-O bond lengths range from 1.90(2) to 2.27(2) A, the order of variation being Cu-O(thd) 3OR. For compound 6, the thd, OR and Pr1OH ligands are bonded asymmetrically to the three metallic centres. Each barium atom bears a chelating thd ligand, two other thd are bridging-chelating, linking the two barium atoms, and one barium, Ba(2), to the copper atom, respectively. The nitrogen-donor sites of the two μ3-aminoalkoxide ligands interact with the copper and Ba(2) centres. The two isopropanol molecules are bonded to the other barium, Ba(1): the solvate is stabilized by intramolecular hydrogen bonds. This allows the barium atoms to reach high coordination numbers, seven and eight, and the copper atom to be pentacoordinated. The Ba-O bond lengths range from 2.59(1) to 2.87(1) A. The Ba-N bond distance is 2.85(1) A. Compounds 4 and 5 are volatile; 5 loses its THF upon sublimation to yield 4.