Acetylacetone solubilities

The orange-red titanium acetylacetone chelates are soluble in common solvents. These compounds are coordinately saturated (coordination number equals 6) and thus much more resistant to hydrolysis than the parent alkoxides (coordination number 4). The alkoxy groups are the moieties removed by hydrolysis. The initial product of hydrolysis is beheved to be the bis-hydroxy bis-acetylacetone titanate, (HO)2Ti(acac)2, which oligomerizes to a... 

A family of Ti(III) derivatives roughly parallels those of Ti(IV). Titariium(III) chelates are known, eg, titanium ttisacetylacetonate [14284-96-9] prepared in benzene from titanium trichloride, acetylacetone, and ammonia (185). This deep-blue compound is soluble in benzene but insoluble in water. 

If a neutral chelate formed from a ligand such as acetylacetone is sufficiently soluble in water not to precipitate, it may stiH be extracted into an immiscible solvent and thus separated from the other constituents of the water phase. Metal recovery processes (see Mineral recovery and processing), such as from dilute leach dump Hquors, and analytical procedures are based on this phase-transfer process, as with precipitation. Solvent extraction theory and many separation systems have been reviewed (42). 

Cobalt(II) can be separated from cobalt(III) as the acetylacetonate (acac) compounds by extraction of the ben2ene soluble cobalt(Ill) salt (14). Magnesium hydroxide has been used to selectively adsorb cobalt(Il) from an ammonia solution containing cobalt(Il) and cobalt(Ill) (15). 

Vanadium (III) acetonylacetonate [13476-99-8] M 348.3, m 181-184°, 185-190°, pKj 2.92, pK 3.5(for aquo V hydrolysis). Crystd from acetylacetone as brown plates. It can be distilled in small quantities without decomposition. It is soluble in CHCI3 and CgHg and evaporation of a CHCI3 solution yields brown crystals which are washed with cold EtOH and dried in vacuum or at 100° in a CO2 atmosphere. Under moist conditions it readily oxidises [V(AcAc)3 lo V(AcAc)20]. [J Chem Soc 103 78 1913, Inorg Synth 5 105 1957 Anal Chem 30 526 I958 UV J Am Chem Soc 80 5686 1958.]... 

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. 

The acetylacetonates are stable in air and readily soluble in organic solvents. From this standpoint, they have the advantage over the alkyls and other alkoxides, which, with the exception of the iron alkoxides, are not as easily soluble. They can be readily synthesized in the laboratory. Many are used extensively as catalysts and are readily available. They are also used in CVD in the deposition of metals such as iridium, scandium and rhenium and of compounds, such as the yttrium-barium-copper oxide complexes, used as superconductors. 1 1 PI Commercially available acetyl-acetonates are shown in Table 4.2. 

The reaction of Rh(I) derivatives such as Rh(acac)(CO)2 (acac = acetylaceton-ate) with dendrimers of generation 1,5 and 6 also proceeds readily at room temperature (Scheme 25). The complexation is unambiguously characterized in all cases by the appearance of a doublet (1JpRh=175 Hz) in the 31P-NMR spectra and corroborated by H NMR (two different CH3 groups for the acac moieties due to the decrease of symmetry of rhodium in complexes). The poor solubility of complexes of generations 5 and 6 precludes their characterization by 13C... 

Reaction with chelating agents. Such reactions have been used primarily for partial dealumination of Y zeolites. In 1968, Kerr (8,21) reported the preparation of aluminum-deficient Y zeolites by extraction of aluminum from the framework with EDTA. Using this method, up to about 50 percent of the aluminum atoms was removed from the zeolite in the form of a water soluble chelate, without any appreciable loss in zeolite crystallinity. Later work (22) has shown that about 80 percent of framework aluminum can be removed with EDTA, while the zeolite maintains about 60 to 70 percent of its initial crystallinity. Beaumont and Barthomeuf (23-25) used acetylacetone and several amino-acid-derived chelating agents for the extraction of aluminum from Y zeolites. Dealumination of Y zeolites with tartaric acid has also been reported (26). A mechanism for the removal of framework aluminum by EDTA has been proposed by Kerr (8). It involves the hydrolysis of Si-O-Al bonds, similar to the scheme in Figure 1A, followed by formation of a soluble chelate between cationic, non-framework aluminum and EDTA. 

Figure 4.24 shows a decrease in for acetylacetone with increasing number of methyl groups in the substituted benzene solvent. Since acetylacetone is more soluble in aromatics than in aliphatics, as illustrated by the K r sequence ... 

The structure of [Fe(MeCOCOCHCOMe)3] has been determined/ of [Fe(acac)]3 redetermined at 20K (Fe—0=1.977 to 2.004A).Iron(III) forms mainly 1 1 and 1 3 complexes with acetylacetone and with benzoylacetone in DMF their reduction has been monitored electrochem-ically. " Solubilities, and derived transfer chemical potentials, of [Fe(acac)3] in various binary aqueous solvent mixtures give a measure of preferential solvation. Rate constants have been determined, at 283 K, for formation of 2,4-octanedione and 2,4-nonanedione complexes of iron(III). ... 

Photoreduction of cobalt(III) complexes in nonaqueous solvent systems has been little studied because of the limited solubility of cobalt(III) complexes and their tendency to photooxidize the solvent. Irradiation with 365-mjj. light of cis- or trans-Co(en)2C 2 + and Co(en)2Cl(DMSO)2+ in dimethylsulfoxide (DMSO) leads rapidly to production of a green tetrahedral cobalt(II) product apparently with concurrent solvent oxidation.53,71 Irradiation with 365-mjx light of the molecular Co(acac)3 in benzene rapidly gives a red precipitate which may be the cobalt(II) acetylacetonate.53... 

The Mannich reaction is a particularly good method of introducing a reactive functional group into a sensitive aromatic nucleus. The reaction has been very useful in ferrocene chemistry. Treatment of chromium acetylacetonate under Mannich conditions yielded a tris-V,N-dimethylaminomethyl chelate (XXXIII). This remarkable substance was very difficult to purify because of its extreme solubility in all solvents ranging from n-heptane to water. The trisamino chelate (XXXIII) is a deep purple, hydroscopic oil and behaves like a typical organic amine. Reaction of this amine with methyl iodide afforded a trisquater-nary ammonium salt (XXXIV), soluble in water but insoluble in organic solvents. When this salt (XXXIV) was treated with cyanide ion, trimethylamine was lost and the cyanomethyl chelate (XXXV) was formed. 

Vanadium (III) acetonylacetonate [13476-99-8] M 348.3, m 181-184°, 185-190°. Crystd from acetylacetone as brown plates. It can be distilled in small quantities without decomposition. It is soluble in CHCI3 and CgHg and evaporation of a CHCI3 solution yields brown crystals which are washed with cold EtOH... 

Acetylacetone reacts with H2S and HC1 in the presence of a metal ion to give the complex (60) with the unstable dithio-jS-diketone before the latter dimerizes.247 The complex [ML2] (LH = dithio-/J-diketone M = Co, Ni, Pd, Pt, Zn, Cd and Hg) and ML3 (M = Cr, Fe, Ru, Os, Co, Rh, Ir) are known they are deeply coloured, stable in air, and, like complexes of monothio-/ -diketones, insoluble in water but readily soluble in organic solvents.248... 

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