Abstract
The solution viscosity of poly(3-vinyl-10-methylphenothiazine) in 1,2-dichloroethane was found to decrease by as much as 50% on exposure to ultraviolet light (λ>290 nm) in the presence of carbon tetrachloride. The reduced viscosity again returned to the initial value by the addition of reductants, such as sodium dithionite. Absorption and ESR measurements of the solution suggested the formation of radical cations of pendant methylphenothiazine (MPT) groups by the interaction of the photoexcited MPT with carbon tetrachloride. Aggregation of ion-pairs of the cations and chloride ions due to dipole–dipole interactions is considered to be the driving force of the chain contraction. The addition of sodium dithionite reduces the radical cations to neutral forms and the chain again returns to the initial random conformation.
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M. Irie and M. Hosoda, Makromol. Chem., Rapid Commun., 6, 533 (1985).
H. J. Shine and E. E. Mach, J. Org. Chem., 30, 2130 (1965).
D. Clarke, B. C. Gilbert, P. Hanson, and C. M. Kirk, J. Chem. Soc., Perkin Trans. 2, 1103 (1978).
Y. Morishima, Y. Itoh, and K. Koyagi, J. Polym. Sci., Polym. Chem. Ed., 21, 953 (1983).
Y. Morishima, I. Akihara, H. S. Lim, and S. Nozakura, Macromolecules, 20, 978 (1987).
E. Gipstein, W. A. Hewett, and O. U. Need, J. Polym. Sci., A-1, 8, 3285 (1970).
W. H. Hamill, “Radical Ions,” E. T. Kaiser and L. Kevan, Eds., Interscience, New York, 1968.
H. J. Shin, D. R. Thompson, and C. Veneziani, J. Heterocycl. Chem., 4, 517 (1967).
B. Badger and B. Brocklehurst, Trans. Faraday Soc., 65, 2576 (1967).
B. Badger and B. Brocklehurst, Trans. Faraday Soc., 65, 2582 (1967).
B. Badger and B. Brocklehurst, Trans. Faraday Soc., 65, 2588 (1967).
S. Irie, H. Horii, and M. Irie, Macromolecules, 13, 1355 (1980).
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Kungwatchakun, D., Hayashi, K. & Irie, M. Photoresponsive Polymers. Photostimulated Viscosity Change of Poly(3-vinyl-10-methylphenothiazine) in 1,2-Dichloroethane in the Presence of Carbon Tetrachloride. Polym J 20, 377–381 (1988). https://doi.org/10.1295/polymj.20.377
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DOI: https://doi.org/10.1295/polymj.20.377