Aluminum compounds, acetylacetonate

Dicyclopentadiene is also polymerized with tungsten-based catalysts. Because the polymerization reaction produces heavily cross-Unked resins, the polymers are manufactured in a reaction injection mol ding (RIM) process, in which all catalyst components and resin modifiers are slurried in two batches of the monomer. The first batch contains the catalyst (a mixture of WCl and WOCl, nonylphenol, acetylacetone, additives, and fillers the second batch contains the co-catalyst (a combination of an alkyl aluminum compound and a Lewis base such as ether), antioxidants, and elastomeric fillers (qv) for better moldabihty (50). Mixing two Uquids in a mold results in a rapid polymerization reaction. Its rate is controlled by the ratio between the co-catalyst and the Lewis base. Depending on the catalyst composition, solidification time of the reaction mixture can vary from two seconds to an hour. Similar catalyst systems are used for polymerization of norbomene and for norbomene copolymerization with ethyhdenenorbomene. 

Ziegler-type catalysts obtained from an organic acid salt or acetylacetone salt of nickel, cobalt, iron, or chromium which reacts with a reducing agent such as an organic aluminum compound. 

Layered crystalline titanates (CT) [Anthony and Dosch, U.S. Patent 5 177 045 (1993)] are pillared with tetraethyl orthosilicate, 3-aminopropyltrimethoxysilane, and aluminum(III) acetylacetonate to prepare porous and high surface area supports for sulfided NiMo catalyst. Tetraethyl orthosilicate or aluminum(III) acetylacetonate intercalated CT are prepared by stepwise intercalation. First, the basal distance is increased by n-alkylammonium ions prior to intercalation with inorganic compounds. However, an aqueous solution of 3-aminopropyltrimethoxysilane can directly pillar CT without first swelling the titanate with n-alkylamine. The catalytic activities for hydrogenation of pyrene of sulfided NiMo supported silica or alumina pillared CT are higher than those of commercial catalysts (Shell324 and AmocatlC). The silicon and aluminum contents of the pillared CT, used as supports, have considerable effects on the catalytic activities and physical properties of the supports. 

The catalysts for these compounds are based on aluminum (Nippon Zeon) or tin (Daiso) (12,13). The preferred catalysts are triaLkylalurninum—water combinations used with or without a chelating agent such as acetylacetone. Except for minor variations, few changes in catalyst composition have been made since it was first formulated. 

Examples of w-allylnickel-X compounds (X = anionic ligand) other than 77-allylnickel halides which have been used in combination with (alkyl)aluminum halides as olefin oligomerization catalysts are 7r-allyl-nickel acetylacetonate (11) (Section III), 7r-allylnickel aziridide (4, 56), and bis(7r-allyl)nickel (6) (59). In addition to ir-allylnickel halides, organo-nickel halides such as tritylnickel chloride (60, 61) and pentafluoro-phenylbis(triphenylphosphine)nickel bromide (62), or hydridonickel halides, e.g., trans-hydridobis(triisopropylphosphine)nickel chloride (12) (Section III), give active catalysts after activation with aluminum halides... 

Rhodium acetylacetonate differed considerably from the other metal chelates in the acetylation reaction (26). Under the same conditions that had given extensive acetylation of the cobalt and chromium acetylacetonates, the rhodium chelate reacted very slowly and formed only a small amount of the monoacetylated compound (XX). Fortunately, the hydrolytic stability of rhodium acetylacetonate is such that the Friedel-Crafts reaction can be carried out under vigorous conditions that would rapidly degrade the chromium and cobalt chelates. Thus treatment of rhodium acetylacetonate with acetyl chloride and aluminum chloride in dichloroethane afforded the mono- and diacetylated chelates (XX and XXI). No triacetylated chelate was isolated from this reaction. In a similar manner butyryl-and benzoyl-substituted rhodium chelates (XXIII and XXIV) have been prepared. These and other experiments indicate that the rhodium acetylacetonate ring is less reactive than the cobalt or chromium rings. 

In the above examples, the nucleophilic role of the metal complex only comes after the formation of a suitable complex as a consequence of the electron-withdrawing effect of the metal. Perhaps the most impressive series of examples of nucleophilic behaviour of complexes is demonstrated by the p-diketone metal complexes. Such complexes undergo many reactions typical of the electrophilic substitution reactions of aromatic compounds. As a result of the lability of these complexes towards acids, care is required when selecting reaction conditions. Despite this restriction, a wide variety of reactions has been shown to occur with numerous p-diketone complexes, especially of chromium(III), cobalt(III) and rhodium(III), but also in certain cases with complexes of beryllium(II), copper(II), iron(III), aluminum(III) and europium(III). Most work has been carried out by Collman and his coworkers and the results have been reviewed.4-29 A brief summary of results is relevant here and the essential reaction is shown in equation (13). It has been clearly demonstrated that reaction does not involve any dissociation, by bromination of the chromium(III) complex in the presence of radioactive acetylacetone. Furthermore, reactions of optically active... 

Other reagents that have been used to reduce support-bound aromatic nitro compounds include phenylhydrazine at high temperatures (Entry 5, Table 10.12), sodium borohydride in the presence of copper(II) acetylacetonate [100], chromium(II) chloride [196], Mn(0)/TMSCl/CrCl2 [197], lithium aluminum hydride (Entry 3, Table... 

Related to jS-diketones are metalla-/ -diketones, whose distinctive chemistry is a recent development. In these, the methine group of a conventional diketonate is replaced with an organometallic moiety such as m-Mn(CO)4, m-Re(CO)4, /<2c-Mn(CO)3(RNC) or C5H5Fe(CO).519 Exemplary is Al Mn(MeCO)2(CO)4 3, which is prepared in a two-step synthesis. Addition of methyllithium to Mn(CO)5COMe forms Li[Mn(MeCO)2(CO)4] which, when treated with aluminum chloride, provides the tris(chelate) compound.520 An X-ray study showed that the MnC202Al ring is essentially planar with Mn—C(acyl) bond distances indicative of a bond order of ca. 1.2. The O—O bite distance, 2.73 A, is about the same as that of acetylacetonate in Al(MeCOCHCOMe)3.521 As in the... 

Aluminum acetylacetonate, 2 25 Aluminum bromide, 3 30 of high purity, 3 33 Aluminum chloride, compound with selenium(IV) chloride, 5 127 Aluminum complex compounds, anions, oxalato, K3[A1(Cs04)3]-3HsO, 1 36... 

BR with narrow MMDs (Mw/Mn > 3.5) and a low solution viscosity can also be obtained by the use of a multi-component catalyst system which comprises the following six components (1) Nd-salt, (2) additive for the improvement of Nd-solubility, (3) aluminum-based halide donor, (4) alumoxane, (5) aluminum (hydrido) alkyl, and (6) diene. The solubility of the Nd-salt is improved by acetylacetone, tetrahydrofuran, pyridine, N,N-dimethylformamide, thiophene, diphenylether, triethylamine, organo-phosphoric compounds and mono- or bivalent alcohols (component 2). The catalyst components are prereacted for at least 30 seconds at 20 - 80 °C. Catalyst aging is preferably performed in the presence of a small amount of diene [397,398 ]. As the additives employed for the increase of the solubility of Nd salts exhibit electron-donating properties it can be equally well speculated that poisoning of selective catalyst sites favors the formation of polymers with a low PDI. 

BEtsH] not only reduces salts of the more noble metals, but even those of Ti, V, or Nb. Aluminum alkyls have also turned out to act as reducing agents for groups 6-11 metals using halide or acetylacetonate salts. Organoaluminum compounds seem to act as stabilizers ofthel l2mn particles. 

Tris[as-(diacetyltetracarbonylmanganese)] aluminum is preparedreadily by treating acetylpentacarbonylmanganese with 1 molar-equivalent of methyllithium at 0° followed by the addition of t/a molar-equivalent of anhydrous aluminum chloride. This complex is isostructural with tris(2,4-pentanedionato)aluminum (where 2,4-pentanedione = acetylacetone) except that the methine group is replaced formally by a Mn(C0)4 group, which suggests that the title compound is one example of a metallo-j3-diketonate type complex. 

At this point Ziegler and his coworkers carried out experiments on the effects of adding various other metal compounds to triethylaluminum. In one of these experiments with zirconium acetylacetonate, ethylene, and triethylaluminum, they found, to their surprise, an autoclave filled with a solid cake of snow-white polyethylene (1. ) Further work revealed that aluminum alkyls in conjunction with certain transition metal compounds of Groups IV-VI, as well as uranium and thorium, were active ethylene polymerization catalysts. Ultimately, Ziegler catalysts were described to be the product of reaction of metal alkyls, aryls, or hydrides of Groups I-IV and certain transition metal compounds of Groups IV-VIII (Reaction 4). The choice of a particular catalyst and experimental conditions is dictated by the structure of the monomer to be polymerized. 

Solvent soluble compounds include zirconium acetylacetonate, zirconium methacrylate, and the family of neoalkoxyl zirconates. Some commercially available zirconates are shown in Table 3. Wang [8] has described the synthesis of a soluble linear Schilf base zirconium-based coordination polymer (N, N, N", A "-tetrasalicylidene-3,3 -diaminoben-zidene) zirconium, and other hybrid copolymers, and has demonstrated improved adhesion on glass and aluminum substrates for poly(methyl methacrylate), polyethylene, and polypropylene when used as hot-melt compounds. 

Aluminum acetylacetonate was first prepared by Combes by treatment of a mixture of hydrous aluminum oxide and acetylacetone with hydrochloric acid. Gach made the compound by the action of aluminum amalgam on acetylacetone, while Urbain and Debierne used anhydrous aluminum chloride and acetylacetone. The recommended procedure was first described by Biltz. ... 

Aluminum acetylacetonate (m.p. 194.6° b.p. 314 to 315.6°) is insoluble in water but soluble iu organic solvents. It is monomolecular both in carbon disulfide and in the vapor state. The compound reacts with alkalies, with acids, and with water at elevated temperatures. The crystal structure has been studied by Sarkar and the electrical polarization by Sutton and coworkers. In a vacuum of 1 mm., subhmation occurs very slowly at 100° but rapidly at 156°. 

Oxetane compounds also polymerize with the aid of aluminum trialkyl-water acetylacetone catalysts. The reactions can take place at 65 °C in heptane and yield very high molecular weight polymers. These polymerizations, however, are ten times slower that similar ones carried out with propylene oxide, using the same catalyst. The reaction conditions and the high molecular weights of the products led to assumptions that coordinated mechanisms of polymerizations take place. ... 

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