Acetylacetone, complexing and

Many acetylacetonate complexes and related /9-diketonates of have been made over the years. Many of these are rather... 

It is apparent that the coordination geometry at the cobalt atom is distorted octahedral. The cyclopentadienyl rings of the phosphinoferrocene fragment are staggered and tilted towards the cobalt atom (by 4.4° in the acetylacetonate complex and by 5.0° in the dithiocarbamate complex). 

Table 27 Stability constants for acetylacetonate complexes and distribution constants (from benzene or...

A series of ions (Pd(II), Bc(II), Ga(in), Fe(III), AI(III) and Cu(II)) were extracted from water as their acetylacetone complexes and baseline resolved on a C g column (A = 330nm) using a 58/35/6/1 methanol/water/dichloromethane/acetic acid mobile phase [151]. Elution was complete in 40 min and detection limits of 1-5 ppb were reported. Peak shapes were uniformly good. The authors used this technique to determine Cu(II) and Fe(III) levels in tap water. It should be noted that other ]3-diketone complexing agents, used like ion pair reagents, should also be eflective here. 

In a systematic analysis of C-H- -tt interactions occurring between metal acetylacetonate complexes and phenyl rings, it was demonstrated that the acetylacetonate chelate... 

A novel all-cobalt nonaqueous RFB has recently been studied [42]. Other than previously mentioned ligands, that is, the acetylacetonate complexes and the 2,2-bipyridine complexes, a third type of ligand complex, bis(acetylacetone) ethyle-nediamine complex, was reported. The cell potential for one-electron disproportion is 2.0 V, and the coulombic efficiency is over 90%. 

Ligand Exchange and Replacement. Three papers deal with ligand exchange at acetylacetonate complexes and the role of the solvent therein, for [Cr(acac)a] in... 

Monodisperse wurtzite CuInxGai xS2 (GIGS) nanocrystals have been synthesized from metal-acetylacetonate complexes and a mixture of sulfur sources as 1-dodecanethiol and tert-dodecanethiol. The morphology of the nanocrystals can be controlled in the form of bullet-like, rod-like, and tadpole-like shapes. The band gap of the nanocrystals increased with the increase in gallium concentration. 

The chelated organic titanates also function as adhesion promoters of the ink binder to printed substrates such as plastic films, paper, and aluminum foil (504). The acetylacetone complexes of titanium are the preferred products for promoting adhesion of printing inks to polypropylene films. 

Kaeriyama and Shimura [34] have reported the photoinitiation of polymerization of MMA and styrene by 12 metal acetylacetonate complex. These are Mn(acac)3, Mo02(acac)2, Al(acac)3, Cu(bzac)2, Mg(acac)2, Co(a-cac)2, Co(acac)3, Cr(acac)3, Zn(acac)2, Fe(acac)3, Ni(a-cac)2, and (Ti(acac)2) - TiCU. It was found that Mn(a-cac)3 and Co(acac)3 are the most efficient initiators. The intraredox reaction with production of acac radicals is proposed as a general route for the photodecomposition of these chelates. 

Discussion. Beryllium forms an acetylacetone complex, which is soluble in chloroform, and yields an absorption maximum at 295 nm. The excess of acetylacetone in the chloroform solution may be removed by rapid washing with O.lM-sodium hydroxide solution. It is advisable to treat the solution containing up to 10 g of Be with up to 10 mL of 2 per cent EDTA solution the latter will mask up to 1 mg of Fe, Al, Cr, Zn, Cu, Pb, Ag, Ce, and U. 

Alkene complexes Alkynyl complexes Ammine complexes Aqueous chemistry Arsine complexes Auranofin Auride ion Aurophilicity Binary compounds Bond lengths acetylacetonate complex alkyls and aryls ammine complexes carboxylates cyanide complexes dialkyl sulphide complexes dithiocarbamates to gold... 

Also increasingly common, as CVD precursors, are many halogen-acetylacetonate complexes, such as trifluoro-acetylacetonate thorium, Th(C5H4F302)4, used in the deposition of thoriated tungsten for thermionic emitters, the trifluoro-acetylacetonates of hafnium and zirconium and the hexafluoro-acetylacetonates of calcium, copper, magnesium, palladium, strontium, and yttrium. 

Komiya, S., and Kochi, J.K. (1977) Reversible linkage isomerisms of p-diketonato ligands. Oxygen-bonded and carbon-bonded stmctures in gold(III) acetylacetonate complexes induced by phosphines. Journal of the American Chemical Society, 99, 3695. 

Studies of the base-hydrolysis mechanism for hydrolysis of technetium complexes have further been expanded to an octahedral tris(acetylacetonato)techne-tium(III) [30], Although a large number of studies dealing with base hydrolysis of octahedral metal(III) complexes have been published [31], the mechanism of the tris(acetylacetonato)metal complex is still unclear. The second-order base hydrolysis of the cationic complex tris(acetylacetonato)silicon(IV) takes place by nucleophilic attack of hydroxide ion at carbonyl groups, followed by acetylacetone liberation, and finally silicon dioxide production [32], The kinetic runs were followed spectrophotometrically by the disappearance of the absorbance at 505 nm for Tc(acac)3. The rate law has the following equation ... 

Another particularly convenient preparative method is the reaction of the corresponding gold(l) acetylacetonate complex with the alkyne, which requires no auxiliary base.42 68-71 This reaction is also useful for the simple acetylides (L)AuC=CH.72 The acetylacetonates can be isolated and introduced as the true reagents, or prepared in situ using the corresponding gold(l) halide complex and Tl(acac) (Equations (16) and (17)).73... 

After our report, many other examples of SIMs based on mononuclear lanthanide complexes have appeared. As relevant examples, we should mention the erbium-organometallic double-decker complexes [11] and the dysprosium-acetylacetonate complexes [12], and the dysprosium-DOTA (H4DOTA, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) complexes reported by Sessoli etal. [13]. 

Other methods reported for the determination of beryllium include UV-visible spectrophotometry [80,81,83], gas chromatography (GC) [82], flame atomic absorption spectrometry (AAS) [84-88] and graphite furnace (GF) AAS [89-96]. The ligand acetylacetone (acac) reacts with beryllium to form a beryllium-acac complex, and has been extensively used as an extracting reagent of beryllium. Indeed, the solvent extraction of beryllium as the acety-lacetonate complex in the presence of EDTA has been used as a pretreatment method prior to atomic absorption spectrometry [85-87]. Less than 1 p,g of beryllium can be separated from milligram levels of iron, aluminium, chromium, zinc, copper, manganese, silver, selenium, and uranium by this method. See also Sect. 5.74.9. 

Oxidative addition of the silyl species to nickel is followed by insertion of unsaturated substrates. Zero-valent nickel complexes, and complexes prepared by reducing nickel acetylacetonate with aluminum trialkyls or ethoxydialkyls, and in general Ziegler-Natta-type systems, are effective as catalysts (244, 260-262). Ni(CO)4 is specific for terminal attack of SiHCl3 on styrene (261). 

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