Then, the monomethinemonoiodine macrobicyclic product underwent a substitution with a cyano group only. The copper I cyanide-triphenylphosphine-acetonitrile system is proposed as a tool for the synthesis of nitrile derivatives of electron-withdrawing heterocycles starting from their halogen-containing precursors.
Classification supporting. Paper Sections Intro. Other sections. Paper Type Research article.
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Clathrochelates.. Synthesis, Structure and Properties
Examples include lithium tetrakis pentafluorophenyl borate, lithium tetrakis pentafluorophenyl aluminate, anilinium tetrakis penta-fluorophenyl borate, and the like. Suitable activators also include organoboranes, which include boron and one or more alkyl, aryl, or aralkyl groups. Suitable activators include substituted and unsubstituted trialkyl and triarylboranes such as tris pentafluorophenyl borane, triphenylborane, tri-n-octylborane, and the like.
These and other suitable boron-containing activators are described in U. Suitable activators also include aluminoboronates—reaction products of alkyl aluminum compounds and organoboronic acids—as described in U.
The optimum amount of activator needed relative to the amount of clathrochelate depends on many factors, including the nature of the clathrochelate and activator, whether a supported catalyst is used, the desired reaction rate, the kind of polyolefin product, the reaction conditions, and other factors. The activator is normally added to the reaction mixture at the start of the polymerization. However, when a supported catalyst system is used, the activator can be deposited onto the support along with the organometallic complex. The clathrochelate and activator are optionally used with an inorganic solid or organic polymer support.
Suitable supports include silica, alumina, silica-aluminas, magnesia, titania, clays, zeolites, or the like.
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The support is preferably treated thermally, chemically, or both prior to use to reduce the concentration of surface hydroxyl groups. A variety of different chemical treatments can be used, including reaction with organo-aluminum, -magnesium, -silicon, or -boron compounds. See, for example, the techniques described in U. The clathrochelate and other components can be deposited on the support in any desired manner.
For instance, the components can be dissolved in a solvent, combined with a support, and stripped. Alternatively, an incipient-wetness technique can be used. Moreover, the support can simply be introduced into the reactor separately from the clathrochelate and other components. Many types of olefin polymerization processes can be used. Preferably, the process is practiced in the liquid phase, which can include slurry, solution, suspension, or bulk processes, or a combination of these.
High-pressure fluid phase or gas phase techniques can also be used. The process of the invention is particularly valuable for solution and slurry processes. Olefin partial pressures normally range from about 15 psig to about 50, psig. More preferred is the range from about 15 psig to about psig. The following examples merely illustrate the invention. Those skilled in the art will recognize many variations that are within the spirit of the invention and scope of the claims.
A side-arm flask is charged with FeCl 2 1. Hydrochloric acid 12 N, 3 drops is added to dissolve all solids. Red crystals precipitate within one minute. The mixture is kept at room temperature for 2 h and then filtered. The solids are washed with hexane mL and dried under vacuum yield: 3. A solution of titanium tetrabenzyl 0.
The mixture warms to room temperature overnight.
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Volatiles are removed under vacuum to afford a red-purple residue 0. The 1 H NMR spectrum CD 2 Cl 2 of a filtered sample indicates the presence of cyclohexyl, benzyl, and hydroxyl groups and is consistent with a mixture that contains predominantly semi-clathrochelate 2, although hexahydroxy compound 1 and clathrochelate 3 are also likely to be present. A solution of 1 0. The mixture turns red-black and warms to room temperature overnight.
Volatiles are removed under vacuum to give a dark red-purple solid 0. This is most consistent with clathrochelate 3 as the principal product. Methylalumoxane product of Albemarle, 0. After 15 min. A two-liter reactor is charged with isobutane 1. The reactor is pressurized with ethylene to psig. The reactor is then vented and cooled to ambient temperature. About 10 g of high-molecular-weight polyethylene is obtained.
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The preceding examples are meant only as illustrations. The following claims define the invention. A method which comprises polymerizing an olefin in the presence of a clathrochelate which comprises: a a transition metal ion; and. The method of claim 1 wherein the ligand is selected from the group consisting of polyaza-, polyazathio-, polythio-, polyoxo-,polyoxothio-, polyazaoxo-, and polyazaoxothiomacrobicyclic ligands. The method of claim 1 wherein the clathrochelate is a tris dioximate. The method of claim 1 wherein both capping atoms of the macropolycyclic ligand are Group 4 transition metals.
The method of claim 1 further comprising an activator. The method of claim 1 wherein both capping atoms of the macropolycyclic ligand are Group 13 atoms, and the clathrochelate is used in combination with an olefin polymerization catalyst. The method of claim 6 wherein the polymerization is performed in the presence of an alkylaluminum compound.