Abstract:
There is disclosed a method for synthesizing polyolefins having a silyl group at one terminus, the method comprising reacting a monomer of an .alpha.-olefin (C.ltoreq.3.ltoreq.10) and a tetrasubstituted silyl radical in the presence of a metallocene catalyst.
Abstract:
Aryloxyaluminoxanes containing the unit ##STR1## where R is unsubstituted or substituted aryl, such as phenyl or naphthyl, are useful as a cocatalysts in Ziegler-Natta and Kaminsky-type olefin polymerization catalysts. They can be formed by reaction of a source of water with an organoaluminum compound containing the desired aryloxy moiety or by reaction of preformed aluminoxane with an organic compound, such as a phenol, containing such a moiety.
Abstract:
The subject invention involves a method of preparing and the constrained geometry catalyst thereby prepared of the general formula Ar'R4(O)Ar"R'.sub.4 M(CH.sub.2 Ph).sub.2 where Ar' is a phenyl or naphthyl group; Ar" is a cyclopentadienyl or indenyl group, R and R' are H or alkyl substituents (C.ltoreq.10) and M is Ti, Zr or Hf. The synthetic method involves a simple alkane elimination approach which permits a "one-pot" procedure. The catalyst, when combined with a cocatalyst such as Pb.sub.3 C.sup.+ B(Ar.sub.3.sup.F).sub.4 BAr.sub.3.sup.F or methyl alumoxane where Ar.sup.F is a fluoroaryl group, is an effective catalyst for the polymerization of .alpha.-olefins such as ethylene, propylene and styrene.
Abstract:
A new class of olefin dimerization catalysts and an efficient method for their preparation is disclosed. B(C.sub.6 F.sub.5).sub.3 reacts quantitatively with Group 4 metallocene type catalysts to yield highly reactive cationic complexes as follows:(L.sub.2 MR.sup.2).sup.+ X.sup.- whereL=R.sub.2 (C.sub.5 H.sub.3); R=a C.sub.3 -C.sub.20 tert-alkyl group; R.sup.2 =a C.sub.1 -C.sub.20 alkyl group, HM=Ti, Zr, Hf;X.sup.- =RB(C.sub.5 F.sub.3).sup.-.sub.3, or methylalumoxane, where R"=a C.sub.1 -C.sub.20 alkyl group, H.These complexes are potent catalysts and may be used in the dimerization of .alpha.-olefins.
Abstract translation:公开了一类新的烯烃二聚催化剂及其制备方法。 B(C6F5)3与第4族金属茂型催化剂定量反应,得到高反应性阳离子络合物如下:(L2MR2)+ X-,其中L = R2(C5H3); R = C 3 -C 20叔烷基; R2 = C1-C20烷基,H M = Ti,Zr,Hf; X = RB(C5F3)-3或甲基铝氧烷,其中R“= C1-C20烷基,H.这些络合物是有效的催化剂,可用于α-烯烃的二聚。
Abstract:
A non-coordinating anion, preferably containing a sterically shielded diboron hydride, if combined with a cyclopenta-dienyl-substituted metallocene cation component, such as a zirconocene metallocene, is a useful olefin polymerization catalyst component. The anion preferably has the formula ##STR1## where R is branched lower alkyl, such as t-butyl.
Abstract:
The regiospecific (1,2-Me.sub.2 C.sub.5 H.sub.3).sub.2 ZrMe.sup.+ MeB(C.sub.6 F.sub.5).sub.3.sup.- mediated ring-opening polymerization of methylenecyclobutane and its copolymerization with ethylene to polyolefins of microstructure--{CH.sub.2 CH.sub.2 CH.sub.2 C(CH.sub.2)]--.sub.n and {--[CH.sub.2 CHR]--.sub.x [CH.sub.2 CH.sub.2 CH.sub.2 C(CH.sub.2)]--.sub.y }.sub.n' respectively, is disclosed.
Abstract:
Polymer-based second harmonic generation materials are disclosed, including electric field poled, chromophore-functionalized polyphenylene ethers with second harmonic coefficients (d.sub.33) as high as 65.times.10.sup.-9 esu, Tg.apprxeq.173.degree. C., and with superior temporal stability of the poling-induced chromophore orientation. Procedures for simultaneously poling and diepoxide cross-linking chromophore-functionalized poly(.rho.-hydroxystyrene) are set forth, resulting in a significant improvement in the temporal stability of chromophore orientation. Chromophore immobilization is disclosed involving highly cross-linkable epoxy matrices. In a first procedure chromophore molecules are embedded in a matrix which can be simultaneously poled and thermally cured. In a second procedure, a functionalized high-.beta. chromophore is synthesized for use as an epoxy matrix component.
Abstract:
The reaction of a samarium catalyst [.eta..sup.5 --(CH.sub.3).sub.5 C.sub.5 ].sub.2 Sm(THF).sub.2 with amino-olefins provides a straightforward route to a heterocyclic compound. Alternatively, the reaction of olefins with the samarium catalyst in the presence of an amine results in an aminoalkane.
Abstract:
Methods and formable compositions for fabricating electrically conductive articles comprising ionically bonding cofacially stacking organomacrocycles and as cofacially stacking phthalocyanines, in which a composition comprising a cofacially stacking phthalocyanine in strong Bronsted acid is formed into a desired shape such as a fiber or film, solidified by removal of the solvent, and provided in fractional valence state.
Abstract:
Disclosed are new semiconductor materials prepared from rylene-(π-acceptor) copolymers. Such copolymers can exhibit high n-type carrier mobility and/or good current modulation characteristics. In addition, the polymers of the present teachings can possess certain processing advantages such as solution-processability and/or good stability at ambient conditions.