JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (Registered in U. S. Patent Office)
(0Copyright, 1959, by the American Chemical Society) NUMBER 4
MARCH 2, 1959
VOLUME81
PHYSICAL AND INORGANIC CHEMISTRY [CONTRIBUTION FROM THE
DEPARTMENT OF CHEMISTRY
O F THE UNIVERSITY O F WISCONSIN]
Temperature and Phase Effects on the Photolysis of Ethyl Iodide B Y RAYH. LUEBBE,JR.,
AND JOHN
E. W I L L A R D
RECEIVED JULY 28, 1958 The photolysis of ethyl iodide by 2537 A. light has been studied in the liquid a t 25' and -70' and in the glass a t - 180". The quantum yields for elementary processes in the reaction mechanism have been deduced to be as follows: (a) for the thermal ethyl radicals which escape caging or diffusive recombination with the parent partner, 0.32 a t 25O, 0.08 a t -70" and (by extrapolation) 5 X lod4 a t - 180"; (b) for production of iodine by processes independent of caging effects (probably C2H6 CzHjI + CzHg C2H4 I ) ca. 0.038; (c) for production of H I by C2H61+ C2H. HI, or other hot process, 0.17 a t 25', 0.18 a t -70" and 0.22 a t -180'. The results are in agreement with earlier work by Bunbury, Williams and Hamill on the photolysis of ethyl iodide in showing a competition between H I and 1 2 for thermal ethyl radicals but indicate that about 18% (rather than
