Chain branching and termination paths in oxidation of n-alkanes: Comprehensive Complete Basis Set-QB3 study on the association of n-pentyl radical with O{sub}2, isomerization and addition of second oxygen molecule

摘要

Association of alkyl radicals with oxygen molecule generates chemically activated peroxy intermediates, which can isomerize and react to form variety of products before stabilization. One low energy isomerization path forms a hydroperoxide alkyl radical. The hydroperoxide-alkyl radical isomers can undergo a chemical activation reaction - associate with second 3{sup left}O{sub}2 opening new diverse pathways to chain branching and termination events. N-pentyl radicals are used as surrogates for higher MW n-alkanes as common linear fuel components in these double peroxide reactions. A comprehensive potential energy diagram for analysis of the secondary hydroperoxide alkyl radicals association with O{sub}2 using the multilevel CBS-QB3 composite method is presented and reactions important to chain branching and termination are discussed.