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在aug-cc-pVTZ基组下采用CCSD(T)和B3LYP的理论方法,研究了OH·与HOBr的反应,并考虑在大气中单个水分子对HOBr+OH·反应机理及动力学的影响.理论计算表明:对于OH+HOBr反应,发现了两个反应通道及其对应的反应前络合物,且计算出的能垒与实验结果符合得较好,当加入一个水分子后,共找到6个不同的反应通道.更加重要的是对于HOBr与H2O…HO·氢键络合物反应,反应能垒降低约1.00 kcal·mol-1.为了评估这些过程在大气化学中的重要性,应用过渡态理论计算各个反应通道的反应速率常数.计算结果表明,在298 K,没有水分子参加反应的反应速率常数为1.77×10-13cm3 molecule-1·s-1,与以前的理论计算一致.当加入水分子时,HOBr…H2O+OH·反应速率常数增加约50倍.
Under the aug-cc-pVTZ basis set, the reaction of OH · with HOBr was studied by CCSD (T) method and B3LYP method. The influence of a single water molecule on the reaction mechanism and kinetics of HOBr + OH · was also considered. Theoretical calculations show that for the OH + HOBr reaction, two reaction channels and their corresponding pre-reaction complexes are found, and the calculated energy barrier is in good agreement with the experimental results. When a water molecule is added, a total of 6 Different reaction channels, and more importantly for HOBr to react with H 2 O ... HO · hydrogen bond complexes, the energy barrier of the reaction is reduced by about 1.00 kcal · mol -1. To assess the importance of these processes in atmospheric chemistry, a transition is applied State theory is used to calculate the reaction rate constant of each reaction channel.The calculated results show that the reaction rate constant of 1.77 × 10-13cm3 molecule-1 · s-1 at 298 K is the same as the previous theoretical calculation. When water molecules are added, the HOBr ... H2O + OH · reaction rate constant increases about 50 times.