Neodymium acetylacetonate

With more robust complexes spectral changes are more likely to result from solvent effects, rather than from ligand exchange. For example the observed shifts in the absorption maxima of spectra of neodymium acetylacetone and neodymium benzoylacetone complexes in methanol-water mixtures were due to solvent effects. ... 

In the vast majority of cases, such syntheses are carried out by the immediate interaction of liquid DMSO with metal salts in absence of solvents. In this respect we note the adducts of DMSO with yttrium and neodymium /ra-acetylacctonatcs [M(acac)3(DMS0)(H20)], obtained by a lingering contact of solid acetylacetonates of the metals above with DMSO [64-68]. 

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 solubility of neodymium carboxylates in organic solvents is also improved by the addition of electron donors such as acetylacetone, tetrahy-drofuran, N,N -dimethylformamide, thiophene, diphenylether, triethylamine, pyridine, organic phosphorus compounds etc. Also the storage stability of neodymium carboxylates in organic solutions (reduction of sediment formation) is increased by these additives. Mixtures of the Nd-precursor and the respective additives are reacted in the temperature range 0-80 °C. The sequential addition of Al-compound and halide donor yield the active polymerization catalysts [409,410]. 

Tetranuclear lanthanide clusters of general formula R4(/i3-OH)2(/r, / -acac)6( -acac)4 (R = Y, Nd acac = acetylacetonate) have also been obtained, but by rather different procedures (Barash et al., 1993 Poncelet and Hubert-Pfalzgraf, 1989). The neodymium cluster was... 

Similarly, preparation of anhydrous and/or unsolvated lanthanide tris-acetylacetonates remained a challenge till 1965, as the efforts to remove ligated water from Ln()S-dik>3.2H2O (obtained from aqueous media) led to hydrolyzed products. However, pure tris-j6-diketonates of lanthanum, praseodymium, and neodymium could be easily synthesized by the reactions of their alkoxides (methoxides/isopropoxides) with 3 equivalents of acetylacetone (acacH) ... 

There are three types of the structures of the metal )9-diketonates in the solid state (viz., insular, cellular, and skeleton). The type of structure of ) -diketonates used in the epoxy compositions affects the catalytic action of these admixtures, so it is possible to regulate the curing rate of the epoxy-anhydride compositions by choosing the necessary modifier [209]. The acetylacetonates of manganese [182-185], zinc [186-189], cobalt [ 190-192,206-208], aluminum [ 193,194], chromium and zirconium [ 184,195, 196], iron [197], and some other metals as well as the )5-diketonates of, for example, neodymium [198], uranium [203], vanadium [205], and the... 

Polymerization and Modification Cyclohexane (60 g) and 1,3-butadiene (6 g) were placed in a pressure bottle having an internal volume of 100 ml under nitrogen atmosphere. Separately, a catalyst was previously prepared by mixing neodymium 2-ethylhexanoate-acetylacetone complex (0.111 imiiol). triisobutylaluminum (3.11 mmol), diisobutylaluminum hydride (1.55 imol) and ethylaluminumsesqui chloride (0.222 nmol) in the presence of 1,3-butadiene (0.555 mmol), and aging the mixture at 30X) for 30... 

---