June, 1940
COMMUNICATIONS TO THE EDITOR
I-Cbnmoyl-l,2-dihydroquinaldonitrile was prepared from 12g. of freshly made cinnamoyl chloride in exactly the same manner as the benzoyl compound; needles from alcohol, m. p. 149-150"; yield, 16 g.
COMMUNICATIONS ELECTROPHORETIC ISOLATION OF CONSTITUENTS OF RAGWEED POLLEN EXTRACTS*
1627
Anal. Calcd. for CisHuON2: C, 79.75; H, 4.93; N, 9.73* Found: c* 79.62; H~ 5.02; N r CONVERSE MEMORIAL LABORATORY HARVARD UNIVERSITY RECEIVED APRIL17, 1940 CAMBRIDGE, MASS.
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THE EDITOR
THE STERIC INHIBITION OF RESONANCE
Sir:
Sir:
It has been shown recently' that the concept of Dialyzed extracts of giant ragweed pollen were the steric inhibition of resonance offers an adestudied with the Tiseliusl moving boundary tech- quate explanation for the differences in acidity obnique a t approximately PH 7.4 and 1.5'. Em- served with trinitrotriphenylmethanes. ploying the Philpot-Svensson2 cylindrical lens sysUsing exactly the same reasoning, we have attem to visualize the boundaries, we have found a tacked this problem from a different point of major constituent which is negatively charged, un- view, i. e., by a consideration of the basic strengths pigmented and migrates more slowly than the of substituted 4-nitro-1-naphthylamines. pigmented constituents. The latter are also negaH - + tively charged. The major unpigmented constituent may constitute as much as 75% of the maI terial in fresh extracts when estimated by the criterion of the integration of the PhilpotSvensson curves. Similar Longsworth3 diagrams have been obtained. The unpigmented fraction is highly skin reactive in individuals with ragweed L hay fever. It may be introduced into the skin by (practically color :ss) electrophoresis in these cases by the positive pole The electron pair of the amino nitrogen atom even though the substance is negatively charged a t (upon which depends the basicity of the molecule) the PH employed. The electrical mobility of the is no longer present in the resonance isomer I. unpigmented constituent is 0.5 X cm. set.-' If the alkyl groups in I are large, they will inhibit in 0.05 d l phosphate buffer at PH 7.0.4 Variations the ability of the group RzN-and the benzene ring have been observed in the pigmented portions of to become coplanar. The result of this must be a the electrophoretic diagrams and apparently dediminution in resonance. This reduction in resopend on the extent and nature of the dialysis as nance by steric hindrance should result in an inwell as the age and treatment of the pollen grains. crease in the electron density a t the amino nitroCOLUMBIA UNIVERSITY AND H. A. ABRAMSONgen atom and thus lead to an increase in basicity. THEMOUNTSINAIHOSPITAL D. H. MOORE H. GETTNER We have shown that the basicity of the substiNEWYORKCITY,AND THE J. GAGARIN tuted amine (I, R = CH,) is much greater than BIOLOGICAL LABORATORIES COLDSPRINGHARBOR L. JENNINGS that of the unsubstituted amine (I, R = H) and RECEIVED MAY17. 1940 that this difference is far too great to be explained * This investigation has been aided by a grant from the Josiah by an inductive effect of the methyl groups. Macy, Jr., Foundation. (1) A. Tiselius, Trans. Foraday Soc., 85, 524 (1937). The decrease in resonance reduces the polar (2) H. Svensson, Kolloid-Z., 87, 190 (1939). character of these molecules2 and should conse(3) L. G. Longsworth and D. A. MacInnes, Chem. Rev., 84, 271 (1939). quently lower the melting points (if other crystal (4) H. A. Abramson, A. Sookne and L. S. Moyer, J. Allergy, 10, 317 (1939); H. A. Abramson and M. H . Gorin, Chem. Prod., 3, 37 (1940).
(1) Wheland and Danish, THISJOURNAL, 63, 1125 (1940). (2) Birtles and Hampson, J. Chcm. Soc., 10 (1937).
