Flash photolysis–UV absorption and long pathlength FTIR–smog chamber studies of several reactions involving C6H5C(O) and C6H5C(O)O2 radicals have been performed. It was determined that reaction of Cl atoms with C6H5CHO proceeds via abstraction of the aldehydic hydrogen to give benzoyl radicals. The sole atmospheric fate of benzoyl radicals is addition of O2 to give peroxybenzoyl radicals. Reaction of C6H5C(O) radicals with molecular chlorine proceeds with a rate constant of (5.9±0.4)×10-11 cm3 molecule-1 s-1 at 296 K and 1–700 Torr total pressure. The UV spectrum of C6H5C(O)O2 radicals (245–300 nm) and the self reaction were investigated simultaneously, yielding σmax=(2.0±0.1)×10-17 cm2 molecule-1 at 245 nm and k16=(3.1±1.4)×10-13 exp[(1110±160) K/T] cm3 molecule-1 s-1, measured from 298 to 460 K. At 338 K, C6H5C(O)O2 radicals react with NO with a rate constant of (1.6±0.4)×10-11 cm3 molecule-1 s-1. At 296 K, C6H5C(O)O2 radicals react with NO2 with a rate constant of (1.1±0.3)×10-11 cm3 molecule-1 s-1 to form C6H5C(O)O2NO2, which undergoes thermal decomposition at a rate of k-4=(2.1-1.5+5.0)×1016 exp[-(13600±400)K/T] s-1 in one atmosphere of air. At 296 K in 100–700 Torr of air k[C6H5C(O)O2+NO]/k[C6H5C(O)2+NO2]=1.44±0.15. Relative rate methods were used to measure k[Cl+C6H5C(O)Cl]=(1.1±0.2)×10-15 cm3 molecule-1 s-1 at 296 K. Uncertainty limits are all two standard deviations. Results are discussed with respect to the literature data and the atmospheric chemistry of benzaldehyde.
进行了涉及C6H5C(O)和C6H5C(O)O2自由基的几种反应的闪光光解-紫外吸收和长光程FTIR-烟雾室研究。研究结果表明,Cl原子与C6H5CHO的反应是通过抽取醛基氢原子来生成苯酰自由基。苯酰自由基在大气中的唯一命运是与O2加成生成过氧苯酰自由基。C6H5C(O)自由基与分子
氯的反应速率常数在296 K和1–700 Torr总压力下为(5.9±0.4)×10^-11 cm³分子^-1 s^-1。对C6H5C(O)O2自由基的紫外光谱(245–300 nm)及其自反应进行了同步研究,得到σmax=(2.0±0.1)×10^-17 cm²分子^-1(在245 nm处)和k16=(3.1±1.4)×10^-13 exp[(1110±160) K/T] cm³分子^-1 s^-1,测量范围为298到460 K。在338 K时,C6H5C(O)O2自由基与NO的反应速率常数为(1.6±0.4)×10^-11 cm³分子^-1 s^-1。在296 K时,C6H5C(O)O2自由基与
NO2的反应速率常数为(1.1±0.3)×10^-11 cm³分子^-1 s^-1,生成C6H5C(O)O2 ,该物质在1个大气压的空气中发生热分解,速率为k-4=(2.1-1.5+5.0)×10^16 exp[-(13600±400)K/T] s^-1。在296 K的100–700 Torr空气中,k[C6H5C(O)O2+NO]/k[C6H5C(O)2+ ]=1.44±0.15。采用相对速率法测得k[Cl+C6H5C(O)Cl]=(1.1±0.2)×10^-15 cm³分子^-1 s^-1,测量温度为296 K。所有不确定性限都为两个标准差。结果与文献数据及
苯甲醛的大气
化学进行了讨论。