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Rate constants and molecular structure
Author(s) -
Johnston Harold S.,
Pitzer Kenneth S.
Publication year - 1959
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690050306
Subject(s) - arrhenius equation , activation energy , thermodynamics , work (physics) , range (aeronautics) , rate equation , kinetic energy , experimental data , mechanism (biology) , reaction rate constant , chemistry , statistical physics , mathematics , materials science , kinetics , physics , statistics , classical mechanics , quantum mechanics , composite material
The methods of relating parameters in the Arrhenius rate equation to fundamental molecular properties are briefly reviewed. The limited applicability of purely theoretical methods is noted, the use and limitations of the standard semiemprical method are surveyed, and recent work based on empirical molecular structure and spectroscopy is described in detail. The recent method makes no attempt to calculate activation energy, but within a limited range of cases it does provide a reliable method of estimating the preexponential factor in the Arrhenius equation and calculating the kinetic isotope effect. In this way the method provides a check on the credibility of experimental data and on the assignment of mechanism. If the mechanism is correct, it provides a method of estimating activation energy from rate data taken at only one temperature. Further developments of this method are anticipated.