The quantum‐mechanical treatment previously applied to benzene, naphthalene, and the hydrocarbon free radicals is used in the calculation of extra resonance energy of conjugation in systems of double bonds, the dihydronaphthalenes and dihydroanthracenes, phenylethylene, stilbene, isostilbene, triphenylethylene, tetraphenylethylene, biphenyl, o, m, and p‐diphenylbenzene, and 1,3,5‐triphenylbenzene. The calculated values, which are in approximate agreement with empirical values from thermochemical data, are used in the discussion of chemical properties and in the formulation of rules regarding conjugation in overlapping systems.
REFERENCES
1.
The same calculations could be made by the use of the method of
Eyring
and Kimball
, J. Chem. Phys.
1
, 239
(1933
).2.
3.
4.
5.
W. Hückel, Theoretische Grundlagen der organischen Chemie, I, p. 359, Akad. Verlag. M. B. H., Leipzig, 1931.
6.
7.
The value for this compound, omitted from the previous paper, is calculated from the heat of combustion by the methods described there.
8.
We are indebted to Professor G. E. K. Branch and to Dr. G. W. Wheland for pointing this out to us.
9.
10.
The values of for addition to a non‐conjugated double bond are 1.08 v.e. less than these, so that such addition reactions are all exothermic.
11.
12.
J. F.
Norris
, R.
Thomas
, and B. M.
Brown
, Ber. Dtsch. Chem. Ges.
43
, 2940
(1910
).See also
J.
Schmidlin
and R.
v. Escher
, Ber. Dtsch. Chem. Ges.
43
, 1153
(1910
). The resultant dichlortetraphenylethane decomposes easily, mainly with the liberation of HCl and the formation of tetraphenylethylene with Cl substituted in the para position in one of the phenyl groups.13.
H. Finkelstein, reference 12.
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© 1933 American Institute of Physics.
1933
American Institute of Physics
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