摘要:
Unbridged fluorenyl containing metallocenes are disclosed along with methods for making the metallocenes. Also disclosed are methods for using the metallocenes as polymerization catalysts. In addition, polymers resulting from such polymerizations are disclosed.
摘要:
The invention relates to a metallocene compound of the formula I ##STR1## where the two indenyl ligands have substitution patterns different from one another. The metallocene compound can be used as catalyst component for olefin polymerization.
摘要:
Fluorenyl-containing metallocenes are disclosed along with methods for making the metallocenes. Also disclosed are methods for using the metallocenes as polymerization catalysts. In addition, polymers resulting from such polymerizations are disclosed.
摘要:
Fluorenyl-containing metallocenes are disclosed along with methods for making the metallocenes. Also disclosed are methods for using the metallocenes as polymerization catalysts. In addition, polymers resulting from such polymerizations are disclosed.
摘要:
Fluorenyl-containing silyl bridged metallocenes, the process of using such metallocenes to polymerize olefins, and the resulting unusual syndiotactic polypropylene are disclosed.
摘要:
Retinoid like activity is exhibited by compounds of the formula ##STR1## where R.sub.1 -R.sub.4 independently are hydrogen, lower alkyl, cycloalkyl or lower alkenyl, A and B independently are hydrogen, lower alkyl, cycloalkyl, lower alkenyl, SR* or OR* where R* is lower alkyl, cycloalkyl or lower alkenyl; Y is lower alkenyl, lower alkynyl, lower cycloalkyl, lower branched chain alkyl or (CH.sub.2).sub.n where n is 0-6; and Z is H, --COOH or a pharmaceutically acceptable salt, ester or amide thereof, --CH.sub.2 OH or an ether or ester derivative, or --CHO or an acetal derivative, or --COR' or a ketal derivative where R' is an alkyl, cycloalkyl or alkenyl group containing 1 to 5 carbons.
摘要:
A vinylsilane compound represented by general formula (I):R.sup.1 CH.sub.2 CH.sub.2 SiR.sub.a.sup.2 (CH.dbd.CH.sub.2)3-a (I)wherein R.sup.1 represents a monovalent alicyclic unsaturated hydrocarbon group selected from the group consisting of a cyclohexenyl group and a bicycloheptenyl group; R.sup.2 represents a monovalent hydrocarbon group free from an aliphatic unsaturated bond; and a represents 1 or 2, is herein disclosed.
摘要:
There are disclosed diethynylated diphenyl hexafluoropropane compounds, which are suitable for forming copolymers and carbon-carbon composites. These compounds are prepared in high yields by first providing a dihalogenated diphenyl hexafluoropropane compound, coupling the dihalogenated compound with ethynyltrimethylsilane in the presence of an organometallic catalyst to form a silylated ethynyl terminated diphenyl substituted compound and subsequently desilylating the compound to form the desired diethynylated diphenyl hexafluoropropane compound.
摘要:
The invention provides a novel organosilicon compound poly(dimethylsilmethylene) methylacetylene compound of the formula MeC.tbd.C--SiMe.sub.2 --CH.sub.2 --SiMe.sub.2).sub.n Me, in which Me is a methyl group and n is a positive integer of 1 to 25. The compound is synthesized by reacting a propynylmagnesium halide of the formula MeC.tbd.CMgX, in which X is a halogen atom, or (propynyl dimethylsilyl)methylmagnesium chloride of the formula MeC.tbd.C--SiMe.sub.2 --CH.sub.2 MgCl with chloromethyl dimethyl chlorosilane in the presence of metallic magnesium and hydrolyzing the reaction product. Specifically, 1-propynyl-1,1,3,3,3-pentamethyl disilmethylene, i.e. the inventive compound with n=1, is synthesized by reacting (propynyl dimethylsilyl)methylmagnesium chloride with trimethyl chlorosilane.
摘要:
A novel branched hydrosilyl-modified polycarbosilane which can be pyrolized to obtain improved yields of silicon carbide. This novel branched hydrosilyl-modified polycarbosilane can be prepared in a one-step reaction from mixtures of silane monomers containing vinyl or halomethyl moieties with silane monomers containing hydrosilyl groups.