Professor Arthur B. Lamb, Editor
Journal of the American Chemical Society
Chemical Laboratory of Harvard University
Cambridge 38, Mass.
Dear Professor Lamb:
I suggest that Professor Bent be advised to correct the statements in his manuscript on pages 3 and 10 dealing with electron affinity of free radicals. It is not true that Wheland has shown that the electron affinity increases as the resonance energy (of the molecule as a whole) increases. Wheland has pointed out that on the basis of the molecular orbital treatment the electron affinity is equal to the coulomb energy q plus the resonance integral multiplied by a small coefficient corresponding to the energy of the added electron. In many cases, as for the triphenylmethyl the coefficient of is zero. Phenylgluoryl is an exception. The calculated coefficient of would give phenylfluoryla larger electron affinity than triphenylmethyl; the calculated increase of about 3,000 cal./mol is much smaller that that reported by Bent and Keevil, however.
Because of the pronounced disagreement of Bent and Clines’s experimental results with theoretical considerations, I find it difficult to accept them. Since there is no reason to believe that the experiments are in error by more than 3,000 or 4,000 cal./mol, this is, of course, no reason for objecting to publication.
Respectfully yours,
Linus Pauling