synopsisCarefully determined cationic copolymerization parameters of cyclic ethers, formals, and esters are collected. Relative reactivity correlates with basicity and free energy. Further correlations of the copolymerization parameters for styrene, the effect of promoters, and the known mechanism of hydrolysis permitted a decision between the carbonium ion (including acylium ion) or the oxoniam ion as the active intermediate of the propagation. Structural features which promote depropagation are identified. Equations describing these possibilities were derived wid briefly discussed. Catalyst and solvent effects limited the correlation possibilities.

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7-(Alkoxycarboiiyl)-7-cyano-l,4-benzoquinone methides 4 with four kinds of alkoxy groups, methyl, ethyl, isopropyl, and butyl, were successfully prepared as pure, isolable crystals. Acid-catalyzed 1,6-addition reactions of 7-cyano-7-(ethoxycarbonyl)-1,4-benzoquinone methide (4a) with phenol and NJfdimethylaniline each gave 1:1 adducts in quantitative yield. Compound 4a reacted with hydrogen chloride to give a 1,6-addition product in situ in quantitative yield, but it did not react with acetic acid. When dissolved in basic aprotic polar solvents such as acetone, acetonitrile, tetrahydrofuran, AUV-dimethylformamide, and dimethyl sulfoxide, 4a spontaneously polymerized to give an oligomer with a molecular weight of 400-6000. Compounds 4 were homopolymerizable with 2,2'-azobis(isobutyronitrile) (AIBN), pyridine, and even boron trifluoride etherate. Pyridine afforded poly-4a with a high molecular weight of 1.1 X 105. Both anionic and radical poly-4a consisted of 1,6 or head-to-tail monomer unit placement. Compound 4a was copolymerizable with styrene in a random fashion in the presence of AIBN to obtain the monomer reactivity ratios: r4a = 3.4 ±0.2 and rst = 0.01 ± 0.08 at 60 °C to allow Q and e values for 4a to be 23 and 1.04, respectively, indicating that it is highly conjugative (highly reactive) and electron-accepting.

Poly(phenylene-chloroethylene) film was prepared by the vapor deposition polymerization of 1,9-dichloro[2.2]paracyclophane and was converted into fully extended π-conjugated poly (phenylene-vinylene) by thermal dehydrochlorination at 300 °C under nitrogen for 1 h.