Accession Number : AD0770689

Title :   The Absolute Measurement of Rate Constants for Some Key Reactions Involving Free Radicals.

Descriptive Note : Annual rept. 1 Jul 72-31 May 73,

Corporate Author : STANFORD RESEARCH INST MENLO PARK CALIF PHYSICAL SCIENCES DIV

Personal Author(s) : Alfassi,Z. B. ; Beadle,P. C. ; Benson,S. W. ; Choo,K. Y. ; Golden,D. M.

Report Date : AUG 1973

Pagination or Media Count : 87

Abstract : Absolute values of the rate constant for isopropyl radical combination have been determined over the temperature range 683-808K. It was found that isopropyl radicals react heterogeneously in a first-order manner with fused silica, probably to produce propylene. The four species (n-butane, 2,3-dimethylbutane, 2,2',3,3',-tetramethylbutane, and isobutane) were decomposed under (VLPP) very low-pressure conditions at temperatures in the vicinity of 1100K. Three model transition states were constructed that fit the low-pressure data thus obtained. Study of the pyrolysis, tBu-NO to tBu+ NO by VLPP yielded the Arrhenius parameters. A new free-volume model for the transition state for dissociation is shown to fit the data.

Descriptors :   *Pyrolysis, *Free radicals, Alkanes, High temperature, Laboratory equipment, Experimental design, Decomposition, Nitroso compounds

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE