March 7, 1935.
Professor A. B. Lamb, Editor
Journal of the American Chemical Society
Chem. Lab. of Harvard University
12 Oxford Street
Cambridge, Mass.
The interesting paper by Professor W. A. Noyes is mainly historical and not suited to the Journal. I recommend that it be not accepted for publication.
In accordance with Professor Noyes request, I am presenting the following remarks, which in the main refer to unimportant points.
P. 2, postulate 4, and p. 14, bottom. The assumption
is apparently made that a definite Lewis electronic structure can always be assigned. Recent work on resonance suggests strongly, that this is not so. For example, consider the nitrate ion. The three-fold axis of symmetry observed for NO3 in NaNO3 is incompatible with the single structure:
[Hand drawn diagram]
, but is compatible with a resonating structure in which each 0 has the average charge -2/3.
P. 14, lines 6 to 9. Has this statement any meaning— is it possible to divide the atom up in such a way as to distinguish definitely between the unshared electrons and the atom as a whole?
P. 18, second paragraph. The statement is incorrect, atoms connected by a double or a triple bond being about 10% or 20% closer together, respectively, than when connected by a single bond. Example: C - C = 1.54 Å in C2H6, C = C = 1.37 Å in C2H4, C = C = 1.22 Å in C2H2.
P. 24, lines 2 and 3. This statement is presumably incorrect; as stated on p. 13, quantum mechanics suggests that electronic isomers of this type do not exist.
P. 24, line 3 — from the bottom. I know of no evidence at all showing that CNH exists.
Very truly yours,
Linus Pauling
Professor of Chemistry
LP:EM
March
7, 1935
