Kinetics and mechanism of hydroxyl radical reaction with methyl hydroperoxide

摘要: The reaction of hydroxyl radical with methyl hydroperoxide, CH{sub 3}OOH, was investigated in the temperature range 203-423 K by pulsed photolytic generation OH and detection laser-induced fluorescence. rate coefficient for overall reaction, + 3}OOH {yields} products (k{sub 1}) measured using {sup 18}OH OD place OH. 3}O{sub 2} production channel H{sub 2}O 1a}) obtained that yields 2}OOH, 2}OOH 1b}), is not observed when monitoring since rapidly falls apart to give back (and 2}O) but studying or 3}OOH. By at 249 K, two-channel mechanism confirmed, values k{sub 1} 1a} were also determined. Both 1 1a show negative activation energies, = (2.93 {plus minus} 0.30) {times} 10{sup {minus}12} exp((190 14)/T) cm{sup 3} molecule{sup {minus}1} s{sup (average 18}OHmore » studies) (1.78 0.25) exp((220 21)/T) {minus}1}, where indicated error {sigma}, including estimated systematic errors {sigma}{sub A} A{sigma}{sub lnA}. 3}OOD least a factor 2 smaller than 1a. thermal decomposition lifetime deduced be shorter 20 {mu}s 205 K. implications our kinetic mechanistic results Earth's atmospheric chemistry are discussed.« less