Accession Number : AD0260890

Title :   STERICAL FACTORS IN UNIMOLECULAR AND BIMOLECULAR REACTIONS

Corporate Author : CORNELL UNIV ITHACA N Y

Personal Author(s) : STEPUKHOVICH,A.D. ; TIMONIN,L.M.

Report Date : DEC 1952

Pagination or Media Count : 1

Abstract : Based on a comparison of the transient state and collision methods, formulas were obtained for the calculation of steric factors in bimolecular and unimolecular reactions. For unimolecular reactions, the calculation of the steric factor by the transient state method requires the knowledge of the activati n energy of the reaction; for bimolecular reactions, the calculation of s does not require the knowledge of E. The steric factor for the unimolecular elementary reaction C2H5 gives C2H+H was calculated; for a value of gamma equals 0.15, it equals one. This indicates the possibility of calculating the rate constant of this reaction by the classical theory formula for unimolecular reactions, taking into account all the vibratory degrees of freedom of the molecule. The steric factor for the elementary reaction C2H4+H gives C2 h5 was calculated to be approximately equal to 0.001. This value is nearly 10 times smaller than the quantity s s b 2 assumed, without any foundation, for experimental work with bimolecular reactions. (Author)

Descriptors :   *CHEMICAL REACTIONS, *REACTION KINETICS, *STEREOCHEMISTRY, MOLECULES, PHYSICAL CHEMISTRY, QUANTUM THEORY

Distribution Statement : APPROVED FOR PUBLIC RELEASE