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在B3LYP/6-311++G(2df,p)水平上优化了标题反应驻点物种的几何构型,并在相同水平上通过频率计算和内禀反应坐标(IRC)分析对过渡态结构及连接性进行了验证.采用双水平计算方法HL//B3LYP/6-311++G(2df,p)对所有驻点及部分选择点进行了单点能校正,构建了CH2SH+NO2反应体系的单重态反应势能剖面.研究结果表明,CH2SH与NO2反应体系存在4条主要反应通道,两个自由基中的C与N首先进行单重态耦合,形成稳定的中间体HSCH2NO2(a).中间体a经过C—N键断裂和H(1)—O(2)形成过程生成主要产物P1(CH2S+trans-HONO),此过程需克服124.1kJ·mol-1的能垒.中间体a也可以经过C—N键断裂及C—O键形成转化为中间体HSCH2ONO(b),此过程的能垒高达238.34kJ·mol-1.b再经过一系列的重排异构转化得到产物P2(CH2S+cis-HONO),P3(CH2S+HNO2)和P4(SCH2OH+NO).所有通道均为放热反应,反应能分别为-150.37,-148.53,-114.42和-131.56kJ·mol-1.标题反应主通道R→a→TSa/P1→P1的表观活化能为-91.82kJ·mol-1,此通道在200～3000K温度区间内表观反应速率常数三参数表达式为kCVT/SCT=8.3×10-40T4.4exp(12789.3/T)cm3·molecule-1·s-1.
The geometry of the title reactive site species was optimized at the B3LYP / 6-311 ++ G (2df, p) level, and the transition states and their structures were characterized by frequency analysis and intrinsic reaction coordinate (IRC) analysis at the same level Connectivity was verified.Using the double horizontal calculation method HL // B3LYP / 6-311 ++ G (2df, p), all the stationary points and some selective points were corrected by single point to construct the CH2SH + NO2 reaction system The results show that there are four main reaction channels in the reaction between CH2SH and NO2, and C and N in the two free radicals are firstly singlet coupled to form a stable intermediate HSCH2NO2 (a). The middle The main product P1 (CH2S + trans-HONO) is formed through the C-N bond cleavage and the formation of H (1) -O (2) in bulk a, which needs to overcome the energy barrier of 124.1 kJ · mol -1. Can be converted into the intermediate HSCH2ONO (b) via C-N bond cleavage and C-O bond formation. The energy barrier of this process is as high as 238.34 kJ · mol-1.b and then undergoes a series of rearrangement isomeric transformations to give the product P2 ( (CH2S + cis-HONO), P3 (CH2S + HNO2) and P4 (SCH2OH + NO) .All channels were exothermic and the responses were -150.37, -148.53, -114.42 and -131.56 kJ · mol- Title reaction master The apparent activation energy of channel R → a → TSa / P1 → P1 is -91.82kJ · mol-1. The apparent reaction rate constant of this channel in the temperature range of 200-3000K is kCVT / SCT = 8.3 × 10-40T4.4exp (12789.3 / T) cm3 · molecule-1 · s-1.