Accession Number : AD0633801

Title :   COMPETITIVE UNIMOLECULAR DECOMPOSITION PROCESSES IN CHEMICALLY ACTIVATED SYSTEMS. 3-HEXYL RADICAL.

Descriptive Note : Technical rept.,

Corporate Author : WASHINGTON UNIV SEATTLE DEPT OF CHEMISTRY

Personal Author(s) : Tardy,D. C. ; Rabinovitch,B. S. ; Larson,C. W.

Report Date : 05 JUN 1966

Pagination or Media Count : 42

Abstract : A general formulation of the rates of competitive unimolecular reactions is given and various relationships between the rates, and between the energetics, of competing processes are described. The relative and absolute rates of decomposition, C-C-C-C.-C-C* to .CH3+C5H10-1 to .C2H5 + C4H8-1, were measured at pressures from 0.004 to 90 mm Hg for vibrationally excited 3-hexyl radicals, chemically activated by the addition of hydrogen atoms to trans-3-hexene at 300C. Use of a quantum-statistical model for k sub E in the general relations provides good theoretical agreement with the experimental data at all pressures. The results can also be used to lead to either of two alternative conclusions: that D-null (CH3-H) - D-null (C2H5-H) is 5.4 kcal/mole, or that the difference in critical energies for addition of methyl to pentene-1, Em-null, and of ethyl to butene-1, Ee-null is Em-null -Ee-null = -0.4 kcal. In the second paper, evidence is presented that triplet methylene radicals may, under certain conditions, insert into C-H bonds.

Descriptors :   (*FREE RADICALS, DECOMPOSITION), (*ALKANES, CHEMICAL REACTIONS), REACTION KINETICS, MOLECULAR ENERGY LEVELS, EXCITATION, THERMOCHEMISTRY, ALKENES, HEAT OF REACTION, CHEMICAL BONDS, VIBRATION

Subject Categories : Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE