An experimental and theoretical study of the reactions OIO+NO and OIO+OH.
An experimental and theoretical study of the reactions OIO+NO and OIO+OH.
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DOI：
10.1021/jp055364y
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发表时间：
2006-01
期刊：
影响因子：
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通讯作者：
J. Plane;D. M. Joseph;B. Allan;Stephen H. Ashworth;J. S. Francisco
中科院分区：
文献类型：
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作者：
J. Plane;D. M. Joseph;B. Allan;Stephen H. Ashworth;J. S. Francisco
通过脉冲激光光解/时间分辨腔衰荡光谱研究了OIO+NO反应的动力学，得到k（235-320 K）=7.6（+4.0）（-3.1）x 10（-13）exp[（607+/-128）/T] cm 3 molecule-1 s-1。OIO+NO势能面上的量子计算表明，反应物形成一个弱结合的OIONO中间体，然后解离成产物IO+NO2。Rice-Ramsberger-Kassel-Markus（RRKM）计算结果与实验结果雅阁较好。最稳定的潜在产物IONO 2不能形成，因为需要OIONO的显著重排。OIO+OH的反应，然后通过量子计算的势能面上的相关的固定点进行了研究。非常稳定的HOIO 2分子可以通过直接复合形成，但是由于显著的能垒，HO 2 +IO和HOI+O2的双分子反应通道是封闭的。RRKM计算HOIO 2复合速率系数得出krec，0=1.5x10（-27）（T/300 K）（-3.93）cm 6 molecule-2 s-1，krec，infinity=5.5x10（-10）exp（46/T）cm 3 molecule-1 s-1，Fc=0.30。这两个反应的速率系数是足够快的，在290 K和1个大气压的压力下，这些反应在气相和气溶胶化学在海洋边界层的大气中发挥了潜在的重要作用。
The kinetics of the reaction OIO+NO were studied by pulsed laser photolysis/time-resolved cavity ring-down spectroscopy, yielding k(235-320 K)=7.6(+4.0)(-3.1) x 10(-13) exp[(607+/-128)/T] cm3 molecule-1 s-1. Quantum calculations on the OIO+NO potential-energy surface show that the reactants form a weakly bound OIONO intermediate, which then dissociates to the products IO+NO2. Rice-Ramsberger-Kassel-Markus (RRKM) calculations on this surface are in good accord with the experimental result. The most stable potential product, IONO2, cannot form because of the significant rearrangement of OIONO that would be required. The reaction OIO+OH was then investigated by quantum calculations of the relevant stationary points on its potential-energy surface. The very stable HOIO2 molecule can form by direct recombination, but the bimolecular reaction channels to HO2+IO and HOI+O2 are closed because of significant energy barriers. RRKM calculations of the HOIO2 recombination rate coefficient yield krec,0=1.5x10(-27) (T/300 K)(-3.93) cm6 molecule-2 s-1, krec,infinity=5.5x10(-10) exp(46/T) cm3 molecule-1 s-1, and Fc=0.30. The rate coefficients of both reactions are fast enough around 290 K and 1 atm pressure for these reactions to play a potentially important role in the gas phase and aerosol chemistry in the marine boundary layer of the atmosphere.