ESR-Untersuchung der behinderten Rotation der CH₂-Gruppe im photolytisch erzeugten H₂C — CO — CH₃-Radikal

Abstract

Abstract The radical H 2 C -CO -CH 3 was produced in an acetone/H 2 O/H 2 O 2 solution by photolysis using techniques similar to those developed by LIVINGSTON and ZELDES. The temperature dependence of the ESR spectrum indicates restricted rotation of the CH 2 -group relative to the rest of the molecule. A complete line-shape analysis of the spectrum at various temperatures leads to Arrhenius-para-meters E a = (9.4 ± 0.5) kcal/mol and 10 log k 0 = 12.9 ± 0.3 which can be interpreted in the frame of the simple HMO theory.