ISSN:
0887-624X
Keywords:
substituted quinone methide
;
polymerizability
;
conjugative monomer
;
electron-accepting monomer
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
7,7-Bis(methoxycarbonyl)-, 7,7-bis(ethoxycarbonyl)-, and 7,7-bis(isopropoxycarbonyl)-1,4-benzoquinone methides (4a, 4b, and 4c) were successfully prepared as pure, isolable yellow-orange needles. The values of the first reduction potential for 4a, 4b, and 4c were measured in dichloromethane containing tetrabutylammonium perchlorate by cyclic voltammetry to be -0.54, -0.55, and -0.55 V, respectively, indicating that the alkyl groups do not significantly affect their electron-accepting properties. An anionic initiator butyllithium induced the homopolymerizations of 4a-c at 0°C, but a cationic initiator boron trifluoride etherate did not of 4a-c at 0°C. Compounds 4a and 4b homopolymerized with a radical initiator 2,2′-azobis(isobutyronitrile) (AIBN), but 4c did not, probably due to a larger steric hindrance effect of the isopropyl group compared with methyl and ethyl groups. Homopolymerizable compound 4a copolymerized with styrene in benzene in the presence of AIBN in a random fashion to give the monomer reactivity ratios r1 (4a) = 2.40 ± 0.40 and r2 (styrene) = 0.01 ± 0.02 at 60°C and the Q and e values of 4a were 21.2 and +1.13, respectively, indicating that 4a is a highly conjugative and electron-accepting monomer, while the nonhomopolymerizable compound 4c copolymerized with styrene in a perfectly alternating fashion in benzene in the presence of AIBN at 60°C. No copolymerizations of 4a or 4c with 7,7,8,8-tetracyanoquinodimethane took place in dichloromethane in the presence of AIBN at 60°C. © 1996 John Wiley & Sons, Inc.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
Permalink
