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  • 1
    ISSN: 0749-1581
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 NMR chemical shifts are reported for a series of seventeen olefins with tetra-, tri-, di- and mono-substitution by nitrile and methoxycarbonyl groups. Analyses of the data for the nitrile, methoxy and carbonyl chemical shifts by multiple linear regression provide a good correlation with the pattern of geminal, cisoid and transoid substitution. The olefinic shielding data are more complicated, and the analysis requires the introduction of pairwise additivity parameters. It scems likely that the greater complexity arises from steric effects associated with cisoid and geminal methoxycarbonyl substituents, which produce deviations from planarity. The empirical relationships, which are reported here, are useful in removing several ambiguities in the spectral assignments. In this series of compounds it is also observed that substituents which are cis to the nitrile, shift the nitrile resonance 1-2 ppm to high field of those for the trans substituents.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary A study of the polymerizability of the first crystalline 1-azabutadiene carrying an electron-withdrawing group on nitrogen is described. A convenient one-step synthesis of 3-methyl-N-(phenylsulfonyl)-1-aza-1,3-butadiene (MPAB) from methacrolein and benzenesulfonamide using titanium tetrachloride and triethylamine led to a crystalline azabutadiene monomer in good yield. With anionic initiators the monomer readily oligomerized to materials in which MPAB has reacted in a 4,1-fashion. Under radical conditions the monomer did not homopolymerize, but did copolymerize with styrene monomers to polymers with molecular weights up to 10,000. These radical copolymerizations involved exlusive 4,3-propagation (vinyl) for the azadiene monomer.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Polymer bulletin 1 (1979), S. 625-629 
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Ten new alternating, either 1∶1 or 1∶2, copolymers of electrophilic trisubstituted ethylenes with electron-rich vinyl monomers, were synthesized by free radical copolymerization.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Polymer bulletin 16 (1986), S. 419-425 
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary 1,2-Dihydroxycyclobutene-3,4-dione (squaric acid) was polycondensed with N-ethyl- and N-(1-butyl)carbazole in polyphosphoric acid to give polymers having 36–43% of 1,2-oriented squarate units. The polymers are insoluble in organic solvents or sulfuric acid. Condensation of 1,2-dichlorocyclobutene-3,4-dione (squaryl dichloride) with N-1-butyl-carbazole in nitrobenzene gave 100% of 1,2-oriented squarate units. This polymer is soluble in most organic solvents, and the molecular weight (¯Mw) is 1900 (DP=6). The electrical conductivity was low, 〈10−9 (ohm cm)−1, and did not increase on treatment with iodine.
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  • 6
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We observed significant piezoelectric activity in cast films of poly(1-bicyclobutanecarbonitrile).
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Polymer bulletin 2 (1980), S. 829-836 
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary 1-Aza-3-oxabicyclo[3.3.1]nonan-2-one, an N-bridgehead bicyclic urethane, polymerized in bulk under the influence of dibutyltin oxide and p-toluenesulfonic acid. In solution the monomer polymerizes in the presence of phosphoric acid. This is only the second example of ring opening polymerization of a bicyclo[3.3.1]nonane. The driving force in the present case is thought to be the relief of strain energy in the monomer conferred by its chair-boat conformation.
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  • 8
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary 2 ,6 ,7-Trioxabicyclo[2.2.1] heptane (I) polymerizes to poly ortho ester (Poly-I) at −78°C with opening of one ring and volume shrinkage. Heating Poly-I with acid isomerized it to an open chain poly-ether formate (Poly-II); this occurred with a large volume expansion. Direct conversion of I to Poly-II by heating with acid occurred with net moderate increase. Monomer I is the first reported monomer which can be polymerized with either shrinkage or expansion as desired. Saponification of Poly-II gave Poly-III, a new water-soluble copolymer.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Polymer bulletin 20 (1988), S. 37-44 
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Self-condensations of 4-chloroimino-2, 5-cyclohexadiene-1-one 1 (benzoquinone N-chloroimine), 2-tert-butyl-4-chloroimino-2, 5-cyclohexadiene-1-one 2, and 3-tert-butyl-4-chloroimino-2, 5-cyclohexadiene-1-one 3 in N-methylpyrrolidinone containing inorganic bases have been investigated. Monomer 1 gave polymers having inherent viscosities of 0.27–0.33 dLg−1. Monomers 2 and 3 only gave oligomers. 1H NMR spectra suggest that polymerization of 1 mainly occurs at C-2 and C-6 positions. A Michael-type addition mechanism, based on the high α-effect nucleophilicity of =NCl, is proposed.
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  • 10
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The initiating ability of tetramethylene zwitterions formed from cyclobutane adducts of donor olefins with TCNE was investigated. Polar solvents increased the ability of vinyl ether-TCNE cyclobutane adducts to initiate the cationic polymerization of N-vinylcarbazole. The concept of charge separation in the tetramethylene zwitterions was also investigated.
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