Acetylac etone

In the early work on the thermolysis of metal complexes for the synthesis of metal nanoparticles, the precursor carbonyl complex of transition metals, e.g., Co2(CO)8, in organic solvent functions as a metal source of nanoparticles and thermally decomposes in the presence of various polymers to afford polymer-protected metal nanoparticles under relatively mild conditions [1-3]. Particle sizes depend on the kind of polymers, ranging from 5 to >100 nm. The particle size distribution sometimes became wide. Other cobalt, iron [4], nickel [5], rhodium, iridium, rutheniuim, osmium, palladium, and platinum nanoparticles stabilized by polymers have been prepared by similar thermolysis procedures. Besides carbonyl complexes, palladium acetate, palladium acetylacetonate, and platinum acetylac-etonate were also used as a precursor complex in organic solvents like methyl-wo-butylketone [6-9]. These results proposed facile preparative method of metal nanoparticles. However, it may be considered that the size-regulated preparation of metal nanoparticles by thermolysis procedure should be conducted under the limited condition. 

The structures of the two isomers were elucidated 1 NMR spectroscopy. The spectrum of die purified major isomer, recorded in CS2 wifo Cr(acac)3 (acac, acetylac-etonate) as a relaxant after 71,000 scans, shows 18 large peaks of nearly equal intensity and 3 small peaks, each with one-half the intensity of tiie major ones (Fig. 2 and Table 2). This spectrum is thus uniquely consistent with one of the two C2 -symmetrical, IPR-satisfying fullerene structures calculated by Manolopoulos and Fowler for C7g (Table 1) (18). As in C70 (20) and 74 (15), each C atom in C73 lies in one of three distinct environments. Five resonances, four of h her and one of lower intensity, originate from C atoms lying at the intersection of three hexagons ( pyrene -lifcc) and show the largest... 

The camphor-derived tridentate amino alcohol 32 (Scheme 17) also catalyzes the conjugate addition reaction of diethylzinc in the presence of nickel acetylac-etonate to afford the product in 83% ee [75]. Similarly the Hgand 33-cobalt acety-lacetonate complex catalyzes the reaction to afford the product in 83% ee [76]. 

As initiators predominantly -diketones (especially 2,4-pentanedione, acetylac-etone, Acac) have been reported (see Figure 6.7 below). Enzymatic H-atom abstraction results in a mesomerically stabilized radical which initiates the polymerization mechanism [8]. A detailed discussion on the influence of the type of mediator and concentration can be found under Section 6.3.2.3. 

Colloids of alloys have been made by the chemical reduction of the appropriate salt mixture in the solution phase. Thus, Ag-Pd and Cu-Pd colloids of varying composition have been prepared by alcohol reduction of mixtures of silver nitrate or copper oxide with palladium oxide (Vasan and Rao 1995). Fe-Pt alloy nanocrystals have been made by thermal decomposition of the Fe and Pt acetylac-etonates in high-boiling organic solvents (Sun et al. 2000). Au-Ag alloy nanocrystals have been made by co-reduction of silver nitrate and chloroauric acid with sodium borohydride (Sandhyarani et al. 2000 He et al. 2002). 

Recently, a well-known trivalent iodine reagent, DIB with low toxicity and high stability was used in the synthesis of substituted pyrroles. The multi-component reaction (MCR) of primary amines 28, nitrostyrenes 29 and acetylac-etone 27 was smoothly performed in the presence of DIB to form substituted pyrroles 30 in good yields. This facile and simple DIB-mediat MCR is applicable for the synthesis of biologically significant tolmetin 31 and related pyrroles (Scheme 2) [18]. 

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