Showing papers on "Norbornene published in 1988"

The photochemical nucleophile–olefin combination, aromatic substitution reaction (Part 2): methanol – cyclic olefins, 1,4-dicyanobenzene

Abstract: Direct irradiation of acetonitrile–methanol (3:1) solutions of 1,4-dicyanobenzene and the cyclic olefins, cyclohexene, 1-methylcyclohexene, norbornene, and 2-methylnorbornene, leads to formation of regio- and stereoisomers of the 1:1:1 (alcohol:olefin:aromatic) adducts. This reaction can be photosensitized by electron transfer; addition of electron donors, biphenyl or phenanthrene, to the irradiation mixture generally increases the efficiency and yield of adduct formation. The efficiency of the reaction and the ratio of isomeric adducts are also affected by the addition of salts, particularly magnesium perchlorate. All of the possible regio- and stereoisomers from cyclohexene and 1-methylcyclohexene have been identified, two from cyclohexene and four from 1-methylcyclohexene. Three of the four possible isomers from norbornene were characterized; the endo,endo isomer was not detected. There are eight possible isomers from 2-methylnorbornene; six were detected and five have been isolated and identified. The...

Block copolymers containing monodisperse segments produced by ring-opening metathesis of cyclic olefins

Abstract: Synthese de copolymeres bisequences catalysee par des titanacyclobutane a partir de norbornene, de benzonorbornadiene et de dicyclopentadiene. Etude des proprietes thermiques

Chemical reactivity of the three-sulfur ring in norbornanetrithiolanes. The S3 transfer reaction

Abstract: Le chauffage de l'endo-phenyl-2 exo-trithia-3,4,5tricyclo [5.2.1.0 2,6 ] decane avec le norbornene a 100°C donne l'exo-trithia-3,4,5tricyclo [5.2.1.0 2,6 ] decane et le phenyl-2 norbornene, par une reaction de transfert de S 3

Co-ordinatively unsaturated diphosphine platinum(II) alkyl cations: a new class of β-agostic complexes

Abstract: Treatment of tris(norbornene)platinum with diphosphines and subsequent protonation affords a series of cationic complexes [Pt(C7H11)(L2)]+(L2= peralkyldiphosphine) in which the norbornyl ligand binds to platinum viaσ-alkyl and β-C–H agostic interactions; the strength of the latter bond varies and has been characterised by n.m.r. and X-ray structure analysis.

Competitive cyclopropanation and cross-metathesis reactions of alkenes catalysed by diruthenium tetrakis carboxylates

Abstract: Addition of ethyl diazoacetate to a mixture of styrene and norbornene containing a catalytic amount of Ru2(OAc)4 promoted both the cyclopropanation and a selective cross-metathesis of the alkenes.

Cycloaddition Reactions of Highly Stabilized Isoquinolinium Methylides to Nonactivated Olefins and Electron-Rich Olefins

Abstract: Highly stabilized isoquinolinium methylides bearing two electron-withdrawing substituents at the ylide carbon undergo cycloadditions with aryl-substituted olefins (acenaphthylene, (E)- and (Z)-stilbenes, indene, and styrene), alkyl-substituted olefins (norbornene, (Z)-3-hexene-1,6-dinitrile, 1-hexene, 2-propen-1-ol, and 3-(trimethylsilyloxy)propene), and electron-rich olefins (vinylene carbonate, butyl vinyl ether, and phenyl vinyl sulfide). These cycloadditions proceed in an exclusively regioselective and mostly stereoselective manner.

Ring-opening hydrogenated copolymer and process for producing the same

Abstract: There are disclosed a polycyclic norbornene or its derivative ring-opening hydrogenated copolymer which contains 90-10% by mole of a repeating unit represented by the following formula [I] or the alkly-substituted derivative, at least a repeating unit represented by the following formula [II] or the alkly-substituted derivative thereof and, as required, a repeating unit represented by the following formula [III], the alkyl-substituted derivative thereof or the alkylidene-substituted derivative thereof, has an intrinsic viscosity [η] of 0.01-20 dl/g as determined in toluene at 25 ° C., and in which at least 50% of the (C C) linkages constituting the main chain are single bonds, and the production of said hydrogenation product ##STR1## wherein represents either a single bond or a double bond.

Reactivity of phenyliodonium bis(arylsulphonyl)methylides towards alkenes and alkynes: crystal structure of 9-phenylsulphonyl-1,2,3,4,4a,9a-hexahydro-1,4- methanofluorene

Abstract: Thermal or photochemical reactions of phenyliodonium bis(arylsulphonyl)methylides with alkenes lead normally to gem-(arylsulphonyl)cyclopropanes. Norbornene and trans-stilbene, however, afford 1-(phenylsulphonyl)indane derivatives. The crystal structure of the title compound {R= 0.038 for 3 468 unique observed reflections [I/σ(I) 3.0]} confirmed the identity of the product with norbornene. Diarylacetylenes give 1-(arylsulphonyl)indenes. Thermal decomposition of the glides involves a new rearrangement, with formation of aryl arenethiosulphonates.

The vibrational spectra (100–1600 cm−1) and scaled ab initio STO‐3G and 3‐21G harmonic force fields for norbornane, norbornene, and norbornadiene

Abstract: The vibrational spectra in the region of 100–1600 cm−1 of norbornane and norbornadiene are reinvestigated, and those of norbornene reported for the first time. On the basis of 3‐21G ab initio force fields, evaluated for each molecule and scaled using overlay refinements of 12 scaling factors, the spectra are assigned and the observed transition frequencies reproduced with an overall average error of 6.2 cm−1. STO‐3G force constants, modified to correct for deficiencies in the stretch/bend interaction force constants but otherwise scaled analogously to 3‐21G, reproduce the final set of assignments to within 10.1 cm−1 on average. The STO‐3G basis is shown to be suitable as a less costly alternative to split‐valence basis sets, particularly for describing the vibrational dynamics of low frequency ring bending and torsional modes.

Norbornene dicarboximide polymers

Abstract: Polymerization of norbornene dicarboximide yields polymers of high Tg, e.g. greater than 170° C. Preferred polymers of N-phenyl norbornene dicarboximide exhibit Tg greater than 210°C.

Metathesis polymerisation of norbornene and its derivatives. Relative stability of tungstacyclobutane intermediates and kinetics of their ring opening to form tungsten–carbene complexes

Abstract: A family of tungstacyclobutane intermediates in the catalytic ring-opening polymerisation of norbornenes have been studied by 1H nmr; their rates of rearrangement into tungsten–carbene complexes are reported and compared

Glass fiber-reinforced norbornene polymer and process for production thereof

Abstract: Object of the present invention is a glass fiber-reinforced norbornene polymer comprising a long glass fiber surface-treated with an amino group-containing silane coupling agent and a polymer obtained by ring-opening bulk polymerization of a norbornene monomer having a tricyclic or higher cyclic structure and a process for the production thereof.

Polynorbornene laminates and method of making the same

Abstract: Printed wiring boards useful for high frequency applications are obtained by laminating a copper foil pretreated with a silane to a polynorbornene prepreg. The prepreg is made by impregnating a fiberglass cloth with a ring-opening polymerized polymer. The copper foil is pretreated with a silane which is capable of improving the bond strength between the copper foil and a norbornene copolymer.

Fluid for traction drive

Abstract: PURPOSE:To obtain the title traction fluid improved in traction coefficient in a wide temperature range, corrosion and oxidation stability, abrasion resistance and economy, by using a specified condensed cyclopentadiene hydrocarbon as a base oil. CONSTITUTION:A cyclopentadiene is thermally (co)polymerized with optionally an alpha-olefin or a monovinylaromatic hydrocarbon in such amounts that the ratio of the norbornene ring double bonds to the cyclopentene ring double bonds is 0.9-1.3, and the obtained (co)polymer is distilled to obtain a component based on the tetramer to hexamer of the cyclopentadiene, which is then hydrogenated to obtain a base oil which is a hydrogenated condensed cyclopentadiene hydrocarbon comprising at least one polymer and having a kinematic viscosity (at 40 deg.C) of 1-200cst. An additive (B) such as an additive (B) such as an antioxidant is optionally added to this oil.

Preparation of block copolymers by ring-opening polymerization of cycloalkenes initiated by a tungstencyclopentylidene complex

Abstract: The possibility of making block copolymers at room temperature from the monomer pairs 2a,b/1, 4/1, 5/1 and 5/3 (1 = norbornene = bicyclo[2.2.1]hept-2-ene; 2a,b = anti- and syn-7-methylbicyclo[2.2.1]hept-2-ene; 4 = methyl endo-bicyclo[2.2.1]hept-5-ene-2-carboxylate; 5 = endo-bicyclo[2.2.1]hept-5-ene-2-carbonitrile; 3 = 1,5-cyclooctadiene) was explored using as initiator of metathesis polymerization in CD2Cl2. The reactions of successive small amounts of the monomers with the catalyst were first followed by 1H NMR to determine the rate of the reaction and the stability of the metal-carbene propagating species. AB and ABA type block copolymers were prepared on this basis and analysed by GPC. An increase in molecular weight after each addition was observed in most cases. Secondary metathesis reactions of double bonds in the polymer chains appear to be significant only for blocks formed from 3.

Method for preparing norbornene structure compound

Abstract: A method for preparing a norbornene structure compound comprises hydrogenating a compound represented by the formula of ##STR1## wherein l, m and n are integers of 0≦l≦3, 0≦m≦8 and 1≦n≦3, respectively, and each of R 1 to R 6 is a hydrogen atom or a hydrocarbon residue having 1 to 3 carbon atoms with or without R 6 forming a ring with R 4 or R 5 , in the presence of a Ziegler type catalyst containing in combination a compound of a transition metal of Groups IV to VI of the periodic table and an organometallic compound of Groups I to III of the periodic table, to thereby convert the compound of the formula (1) into a compound represented by the following formula of ##STR2## wherein l, m and n are the same as above.

Homopolymerization of norbornene by rhenium olefin metathesis catalysts

Abstract: Norbornene was homopolymerized by Re(CO)5Cl/C2H5AlCl2 and Re(CO)5Cl/C2H5AlCl2/1,7-octadiene. In both cases, the homopolymers were essentially of the ring-retention, rather than ring-opened type, even though Re(CO)5Cl/C2H5AlCl2 is known to promote olefin metathesis of acyclic olefins. Although the homopolymers are nearly completely saturated, they show minor unsaturation. Nmr spectral studies of the nature of the double bonds in the polymer supports a simultaneous insertion-olefin methathesis mechanism.

Process for production of molded article of norbornene polymer

Abstract: A process for a production of a molded article of a norbornene polymer, which comprises mixing a starting reaction liquid (liquid A) containing an activator of a methathesis catalyst system with a starting reaction liquid (liquid B) containing a catalyst component of the methathesis catalyst system and supplying the mixture into a mold, wherein a norbornene monomer is incorporated in at least one of the starting reaction liquids and a liquid product obtained by ring-­opening bulk polymerization of a norbornene monomer is used as the viscosity modifier for the starting reaction liquids.