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Rate constants for the gas‐phase reactions of OH radicals with a series of bi‐ and tricycloalkanes at 299 ± 2 K: Effects of ring strain
Author(s) -
Atkinson Roger,
Aschmann Sara M.,
Carter William P. L.
Publication year - 1983
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550150105
Subject(s) - nonane , chemistry , decane , bicyclic molecule , radical , reaction rate constant , octane , cyclohexane , heptane , ring (chemistry) , ring strain , medicinal chemistry , computational chemistry , photochemistry , organic chemistry , kinetics , physics , quantum mechanics
Abstract Relative rate constants for the gas‐phase reactions of OH radicals with a series of bi‐ and tricyclic alkanes have been determined at 299 ± 2 K, using methyl nitrite photolysis in air as a source of OH radicals. Using a rate constant for the reaction of OH radicals with cyclohexane of 7.57 × 10 −12 cm 3 /molec·s, the rate constants obtained are (× 10 12 cm 3 /molec·s): bicyclo[2.2.1]heptane, 5.53 ± 0.15; bicyclo[2.2.2]octane, 14.8 ± 1.0; bicyclo[3.3.0]octane, 11.1 ± 0.6; cis ‐bicyclo[4.3.0]nonane, 17.3 ± 1.3; trans ‐bicyclo[4.3.0]nonane, 17.8 ± 1.3; cis ‐bicyclo[4.4.0]decane, 20.1 ± 1.4; trans ‐bicyclo[4.4.0]decane, 20.6 ± 1.2; tricyclo[5.2.1.0 2,6 ]decane, 11.4 ± 0.4; and tricyclo[3.3.1.1 3,7 ]decane, 23.2 ± 2.1. These data show that overall ring strain energies of ≲4–5 kcal mol −1 have no significant effect on the rate constants, but that larger ring strain results in the rate constants being decreased, relative to those expected for the strain‐free molecules, by ratios which increase approximately exponentially with the overall ring strain.