Kinetic parameters and geometry of the transition state of acyl radical decarbonylation |
| |
Authors: | T S Pokidova E T Denisov A F Shestakov |
| |
Institution: | (1) State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, 030001 Taiyuan, China;(2) Graduate University of Chinese Academy of Sciences, 100039 Beijing, China;; |
| |
Abstract: | Experimental data on acyl radical decomposition reactions (RC·O → R· + CO, where R = alkyl or aryl) are analyzed in terms of the intersecting parabolas method. Kinetic parameters characterizing
these reactions are calculated. The transition state of methyl radical addition to CO at the C atoms is calculated using the
DFT method. A semiempirical algorithm is constructed for calculating the transition state geometry for the decomposition of
acyl radicals and for the reverse reactions of R· addition to CO. Kinetic parameters (activation energy and rate constant) and geometry (interatomic distances in the transition
state) are calculated for 18 decomposition reactions of structurally different acyl radicals. A linear correlation between
the interatomic distance r
#(C…C) (or r
#(C…O)) in the transition state the enthalpy of the reaction (δH
e) is established for acyl decomposition reactions (at br
e = const). A comparative analysis of the enthalpies, activation energies, and interatomic distances in the transition state
is carried out for the decomposition and formation of acyl, carboxyl, and formyl radicals. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|