2.2.6.6- tetramethyl 1-3,5-heptanedione

Europium, tris(2,2,6,6-tetramethyl-3,5-heptanedione-quinuclidine)-stereochemistry, 1, 81 Europium complexes... 

Paramagnetic rare-earth porphyrins, TPPErOH (TPP 5,10,15,20-tetraphenylporphin) and TPPEr(dpm) (dpm 2,2,6,6-tetramethyl-3,5-heptanedionate), emit not only but also S2 fluorescence even if a sequence of the... 

A few observations of photosubstitution in lanthanide complexes have been reported. Irradiation into the f—f bands of [Pr(thd)3], [Eu(thd)3] and [Ho(thd)3] (thd is the anion of 2,2,6,6-tetramethyl-3,5-heptanedione) results in substitution of thd by solvent.153 The proposed mechanism involves intramolecular energy transfer from an f—f excited state to a reactive IL excited state which is responsible for the observed ligand loss. Photosubstitution has also been observed upon direct excitation into the ligand absorption bands of [Tb(thd)3].154... 

Extraction of the rare earths with acetylacetone has been investigated [418, 419] and is found to be enhanced by the decreasing basicity of the rare earth ions. The gas chromatographic separation of rare earth complexes with 2,2,6,6-tetramethyl-3,5-heptanedione has already been mentioned. The acetylacetonate complexes of the rare earths are reported to exist as either anhydrous [420, 421], mono- [422], di- [422] or trihy-drates [422, 423], Stites et al. [424] have studied the pH of the precipitation of several rare earth acetylacetonates and reported the melting points of the complexes. The europium acetylacetonate precipitated at pH 6.5, and melted at 144—45° C. The existence of monomers and dimers for these complexes in nonaqueous solvents has been proposed [421, 425-427],... 

Schwarberg, J. E., Sievers, R. E., Moshier, R. W. Gas chromatographic and related properties of the alkaline earth chelates with 2,2,6,6,-tetramethyl-3,5-heptanedione. Anal. Chem. 42, 1828(1970). 

Photo substitution reactions of Pr, Eu and Ho complexes with the ligand L = 2,2,6,6-tetramethyl-3,5-heptanedione (thd) of the formula Ln(thd)3 have been studied by irradiation into the f-f bands [110]. The corresponding thermal reactions are slow. The ligand thd is replaced by solvent thus... 

McKittrick et al. prepared (Yi cEU c)203 hlms employing just such a strategy (McKittrick et al., 2000). The objective is to produce a compound with photoluminescent and cathodoluminscent properhes suitable for hat-panel displays. Yttrium tris(2,2,6,6-tetramethyl-3,5-heptanedionate) can be decomposed to produce Y2O3 ... 

Miyanaga [2] prepared moderate molecular weight polyglycidol ethers, (II), by polymerizing the corresponding glycidol ether with samarium triisopropoxide, samarium tris(tetramethyl heptanedionate), and yttrium tris(tetramethyl hep-tanedionate) with methyl aluminoxane. 

Figure 4.43. Thermogravimetric analysis of organomagnesium CVD precursors, indicating the dependence of molecular structure on its decomposition temperature. The ligand abbreviations are dpm = 2,2,6,6-tetramethyl-3,5-heptanedionate, TMEDA = Ai, Ai, A, W -tetramethylethylenediamine, hfa = l,l,l,5,5,5-hexafluoro-2,4-pentanedione, HTEEDA = H(W, N, N, A Atetraethylethylene diamine). Reproduced with permission from Chem. Mater. 2005,17(23), 5697. Copyright 2005 American Chemical Society.

---