Acetylacetone, reduction

NH2OH HC1, NH3, NOt, 1,10-phenanthroline, S2-, SCN- + SO -, S20(-, sulfosalicylate, tartrate, thioglycolic acid, thiosemicarbazide, thiocarbohydrazide, thiourea Fe Acetylacetone, (reduction with) ascorbic acid, C2OJ-, citrate, CN-, 2,3-dimercaptopropanol,... 

Other volatile compounds of elements can be used to transport samples into the plasma flame. For example, hydride reduction of mercury compounds gives the element (Hg), which is very volatile. Osmium can be oxidized to its volatile tetroxide (OSO4), and some elements can be measured as their volatile acetylacetonate (acac) derivatives, as with Zn(acac)2. 

Condensation of 2-quinolinecarboxaldehyde 98 with acetylacetone or ethyl acetate gave the acrylate derivatives 99 and 100, respectively. Cyclization of 99 with AC2O afforded the benzindolizine 101 (80ACSA(B)79). Reduction of 100 in presence of Adams catalyst followed by hydrolysis gave 102 (78PJC107) (Scheme 19). 

From Table 3, it can be seen that the reactivity of acyl acetanilide, such as BAA or AAA, is higher than that of the other reductant reported from our laboratory, i.e., acetanilide (AA), N-acetyl-p-methylaniline (p-APT), acetylacetone (AcAc), and ethyl acetoacetate (EAcAc). Moreover, the promoting activities of derivatives of acetoacetanilide were affected by the ortho substituent in benzene ring, and the relative rate of polymerization Rr) decreased with the increase of the bulky ortho substituent to the redox reaction between Ce(IV) ion and substituted acetoacetanilide. 

Deposition occurs at much lower temperature (260-340°C) by the decomposition of metallo-organic compounds such as copper acetylacetonate, Cu(C5H202)2 or by the hydrogen reduction of the copper chelate, Cu(C5HFg02)2 at and more recently of... 

The nozzle of original design was fabricated from a niobium alloy coated with niobium silicide and could not operate above 1320°C. This was replaced by a thin shell of rhenium protected on the inside by a thin layer of iridium. The iridium was deposited first on a disposable mandrel, from iridium acetylacetonate (pentadionate) (see Ch. 6). The rhenium was then deposited over the iridium by hydrogen reduction of the chloride. The mandrel was then chemically removed. Iridium has a high melting point (2410°C) and provides good corrosion protection for the rhenium. The nozzle was tested at 2000°C and survived 400 cycles in a high oxidizer to fuel ratio with no measurable corrosion.O l... 

The mechanism of formation of Pt particles by the or-ganometallic reduction route, however, was found to proceed differently, for example in the reductive stabilization of Pt nanoparticles produced by reacting Pt-acetylacetonate with excess trimethylaluminium. Here, derivates of aluminium alkyls act as both reducing agents and colloidal stabilizers. As was shown by a combination... 

In 2000, Sun and co-workers succeeded in synthesis of monodispersed Fe/Pt nanoparticles by the reduction of platinum acetylacetonate and decomposition of Fe(CO)5 in the presence of oleic acid and oleylamine stabilizers [18]. The Fe/Pt nanoparticle composition is readily controlled, and the size is tunable from 3 to 10 nm in diameter with a standard deviation of less than 5%. For practical use, we developed the novel symthetic method of FePt nanoparticles by the polyol reduction of platinum acetylacetonate (Pt(acac)2) and iron acetylacetonate (Fe(acac)3) in the presence of oleic acid and oleylamine stabilizers in di- -octylether [19,20]. The Fe contents in FePt nanoparticles can be tuned from 23 to 67atomic%, and the particle sizes are not significantly affected by the compositions, retaining to be 3.1 nm with a very narrow size distribution, as shown in Figure 6. 

The liquid-phase reduction method was applied to the preparation of the supported catalyst [27]. Virtually, Muramatsu et al. reported the controlled formation of ultrafine Ni particles on hematite particles with different shapes. The Ni particles were selectively deposited on these hematite particles by the liquid-phase reduction with NaBFl4. For the concrete manner, see the following process. Nickel acetylacetonate (Ni(AA)2) and zinc acetylacetonate (Zn(AA)2) were codissolved in 40 ml of 2-propanol with a Zn/Ni ratio of 0-1.0, where the concentration of Ni was 5.0 X lO mol/dm. 0.125 g of Ti02... 

The reduction of pertechnetate with concentrated hydrochloric acid finally yields the tetravalent state, and no further reduction to the tervalent state takes place. Therefore, the tervalent technetium complex has usually been synthesized by the reduction of pertechnetate with an appropriate reductant in the presence of the desired ligand. Recently, the synthesis of tervalent technetium complexes with a new starting complex, hexakis(thiourea)technetium(III) chloride or chloropentakis(thiourea)technetium(III) chloride, has been developed. Thus, tris(P-diketonato)technetium(III) complexes (P-diketone acetylacetone, benzoyl-acetone, and 2-thenoyltrifluoroacetone) were synthesized by the ligand substitution reaction on refluxing [TcCl(tu)5]Cl2 with the desired P-diketone in methanol [28]. 

Crystals of [Tc(tu)6]Cl3 or [TcCl(tu)5]Cl2 are often employed for the synthesis of technetium(III) complexes. However, since the direct reduction of pertechnetate with excess thiourea in a hydrochloric acid solution yields [Tc(tu)6]3+ in high yield [37], direct use of the aqueous solution of the thiourea complex would be preferable for the synthesis of the technetium(III) complex without isolation of the crystals of the thiourea complex. In fact, technetium could be extracted from the aqueous solution of the Tc-thiourea complex with acetylacetone-benzene solution in two steps [38]. More than 95% extraction of technetium was attained using the following procedure [39] First a pertechnetate solution was added to a 0.5 M thiourea solution in 1 M hydrochloric acid. The solution turned red-orange as the Tc(III)-thiourea complex formed. Next, a benzene solution containing a suitable concentration of acetylacetone was added. After the mixture was shaken for a sufficient time (preliminary extraction), the pH of the aqueous phase was adjusted to 4.3 and the aqueous solution was shaken with a freshly prepared acetylacetonebenzene solution (main extraction). The extraction behavior of the technetium complex is shown in Fig. 6. The chemical species extracted into the organic phase seemed to differ from tris(acetylacetonato)technetium(III). Kinetic analysis of the two step extraction mechanism showed that the formation of 4,6-dimethylpyrimidine-... 

Rh(CO)2(acac)(dppp)] as a catalyst (where acac = acetylacetonate) gives high rates (100-200 turnovers h 1) and selectivities in the reductive carbonylation of methanol to acetaldehyde comparable to the best Co catalysts, but at a much lower temperature (140 °Q and pressure... 

Acetate, (C6H5)4AsC1, citrate, 2,3-dimercaptopropanol, EDTA, I-, Na5P3O10, SO)-, S20)-, tartrate, tiron, tetraphenylarsonium chloride, triethanolamine, thioglycolic acid Acetylacetone, citrate, CN-, EDTA, I-, NH3, N02, SCN-, S20)-, tartrate, triethanol amine Citrate, CN-, EDTA, I-, NH3, N02, SCN-, S20 -, tartrate, urea Reduction to Pu(IV) with sulfamic acid C20)-, citrate, EDTA, F-, tartrate Oxidation to perrhenate Citrate, tartrate, thiourea CN-, thiourea... 

Takacs has reported the cyclization of tu-enedienes catalyzed by an iron(0) complex that is generated in situ through the reduction of iron(m) tris(acetylacetonate) with triethylaluminum in the presence of a ligand such as 2,2 -bipyridine or bisoxazoline (Scheme 100). The 1,4-diene cycloadducts are obtained in very good yields.366... 

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). ... 

The initiator formed from VCLt and A1(C2H5)2C1 is one of the most efficient means for syndioselective polymerization of propene, especially in the presence of a Lewis base such as anisole (methoxybenzene) [Doi, 1979a,b Natta et al., 1962 Zambelli et al., 1978, 1980], Other vanadium compounds such as vanadium acetylacetonate and various vanadates [VO(OR)xClp x), where x — 1,2,3] can be used in place of VCI4 but are more limited in their stereoselectivity [Doi et al., 1979]. Trialkylaluminum can also be used as a coinitiator, but only for VCI4. Syndiotacticity increases with decreasing temperature most of these syndioselective polymerizations are carried out below —40°C and usually at —78°C. The initiators must be prepared and used at low temperatures since most of them undergo decomposition at ambient and higher temperatures. There is considerable reduction of V(III) to V(II) with precipitation of ill-defined products that are low in activity and do not produce syndiotactic polymer, when the initiators are prepared at or warmed to temperatures above ambient. 

Condensation (FeCl, ZnClj, HCl) of these amine salts with methyl vinyl ketone produced 4-methylthleno[2,3-/>]thieno[2,3-h]pyridine and 4-methylthieno[3,2-6]thieno[2,3-6]pyridine, respectively , while acetylacetone (ZnClj) afforded the 2,4-dimethyl derivatives. 5-Ethyl-2-formylthieno[2,3-Z>]thiophene (211) and nitromethane by the Knoevenagel method gave 2-/3-nitrovinyI-5-ethylthienol2,3-6]-thiophene (212) (73%) reduction (LAH) of 212 led to the 2-/3-amino-ethyl analog (213) lEq. (69)]. 

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