2002 Fiscal Year Final Research Report Summary

Spectroscopy and kinetics of radical species related to atmospheric chemistry

Research Project

Project/Area Number	13640502
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Physical chemistry
Research Institution	The University of Tokyo
Principal Investigator	TONOKURA Kenichi The University of Tokyo, Department of Chem. Sys. Engineering, Research Associate, 大学院・工学系研究科, 助手 (00260034)
Project Period (FY)	2001 – 2002
Keywords	Aromatic radical / laser spectroscopy / absorption spectrum / Rate constant
Research Abstract	Knowledge of the kinetics of aromatic hydrocarbon free radicals is of primary importance in the modeling of atmospheric chemical reactions in urban air. Phenyl, phenoxy and benzyl radicals have been found in abundance in urban atmospheres. They also play a key role in high temperature hydrocarbon combustion systems where they are involved in the formation of polycyclic aromatic hydrocarbons and hence of soot. In the present work, we determined the absorption cross-sections of the phenyl, phenoxy and benzyl radicals. Based on the chemical kinetic simulation, the absorption cross-sections for the radicals have been determined. Based on the reaction kinetic simulation, the absorption cross-sections of phenoxy radical at 394.4 nm was determined to be σ_<446.5> = (7±2) x 10^<-18> cm^2 molecule^<-1>. The absorption cross-section of the benzyl radical at 447.7 nm was determined to be (2±1) x 10^<-18>cm^2 molecule^<-1> through analysis of time-dependent absorption traces.