Ytterbium complexes acetylacetone

Ytterbium, trinitratotris(dimethyl sulfoxide)-structure, 1, 97 Ytterbium, tris(acetylacetone)(4-ammo-3-penten-stereochemistry, 1,81 Ytterbium complexes acetylacetone, 2,373 dipositive oxidation state hydrated ions, 3,1109 polypyrazolylborates, 2,255 Ytterbium(III) complexes ethyl glycinate, diacetate... 

The value of a pH of ytterbium hydroxide sedimentation and its control during the course of the synthesis are the necessary conditions when receiving ytterbium complexes. Used oxygen-containing bidentate donors (acetylacetone) should be low basic. In this connection the reaction of interaction of ytteibium salts with such ligands can be carried out in neutral and veiy subacidic environments (pH 5-6). 

X 109 and 8. 9 x 109 s 1 for Ndm and Ybm, respectively. Both the above-described in-termolecular mechanism, as well as an intramolecular pathway in the ternary complex with aad which forms in solution, are responsible for the observation of NIR luminescence in these systems. Addition of water to the toluene solutions quenches the NIR luminescence, while it enhances the visible CL emission of the corresponding solution of Eum and Tbm (Voloshin et al., 2000c). Neodymium and ytterbium tris(benzoyltrifluoroacetonates) display the same CL as tta complexes, although for Ybm its intensity is about 2.5 times lower than for the tta chelate. On the other hand, almost no CL is detected for acetylacetonate complexes (Voloshin et al., 2000a). Thermal or photochemical decomposition of aad also triggers CL from [Pr(dpm)3] and Pr(fod)3], both in the visible (from the 3Pi, 3Po, and 1D2 levels) and in the NIR at 850 nm ( Do -> 3F2 transition) and 1100 nm ( D2 3F4 transition). The excited... 

The first stage of oirr work was the synthesis of lanthanide elements salts (ytterbium and erbium) in a form of acetylacetonates. The rare-earth elements (REE) complexes in most cases have the coordination number (CN) more than six (7, 8, 9, 10 and even 12). CN of REE ions in complexes with organic poly dentate ligands are high and variable [10]. The reason of this phenomenon lies in the big ionic radius, which decreases from 1.06 A (La " ) to 0.88 A (Lu " ) (the effect of lanthanide compression ). The empty site of the coordination sphere is occupied by other ligands water, hydroxyl ions, etc. In IR-spectrum the hydroxyl ion is characterized by a narrow strip at 3700-3600 cm, it has higher frequency than water. Frequency v of water is located in a region of about 3600-3200 cm". ... 

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