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A Correlation between Reactivity towards Free Radicals and Free Valence Number in Polycyclic Aromatics


IN recent papers dealing with theoretical molecular properties derivable on the basis of quantum mechanics, Coulson and others1,2 stated that the free valence number calculated for a given carbon atom should be related to its ability to interact with a free radical, being a measure for the unused bonding power of that atom.

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  1. Coulson, C. A., J. Chim. Phys., 45, 243 (1948). Burkitt, F. H., Coulson, C. A., and Longuet-Higgins, H. C., Trans. Farad. Soc., 47, 553 (1951).

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  2. Daudel, R., et al., Bull. Soc. chim. France, 17, 66 (1950).

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  3. Kooyman, E. C., Rec. Tr. Chim. Pays Bas, 69, 492 (1950). Kooyman, E. C., and Farenhorst, E., ibid., 70, 867 (1951). Cf. Kharasch, M. S., et al., J. Amer. Chem. Soc., 69, 1100, 1105 (1947).

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  4. Kooyman, E. C., Disc. Farad. Soc. on Hydrocarbons, April 1951 (in the press).

  5. Kharasch, M. S., and Sage, M., J. Org. Chem., 14, 537 (1949).

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  6. These were taken from: (a) Berthier, G., et al., C.R. Acad. Sci. Paris, 226, 1906 (1948). (b) Baldock, G., et al., C.R. Acad. Sci. Paris, 228, 931 (1949). (c) Vroelant, C., and Daudel, R., Bull Soc. chim. France, 16, 217 (1949).

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KOOYMAN, E., FARENHORST, E. A Correlation between Reactivity towards Free Radicals and Free Valence Number in Polycyclic Aromatics. Nature 169, 153–154 (1952).

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