... See reference 6d. (13) SM McElvain and JP Schroeder, J . Am. Chem. ... u.16 For 3.5 I I I I I 1 3.0 2-CgHqNCN O J I I 1 I I 0.0 0.2 0.4 0.6 0.6 0- Fig. ... (14) L. P. Hammett, Physical Organic Chemistry, Mc- Graw-Hill Book Co., Inc., New York, N. Y., 1940, p. 184. ...