A theoretical study on the mechanisms and kinetics of the reaction of (CH₃)₃Al (TMA), an important industrial compound, with O₂ has been carried out at the CCSD(T)/6-311++G(3df,2p)//B3LYP/6-311++G(3df,2p) level in conjunction with the conventional transition state theory (TST) calculations. The potential energy surface (PES) of the reaction indicates that the TMA + O₂ system has two pathways leading to different product pairs: the first one passes through a tight transition state with a high energy barrier, 16.9 kcal/mol, producing (CH₃)₂AlO₂ + CH₃ and the other one goes via a loose roaming-like transition state with a much lower energy barrier, 6.8 kcal/mol, yielding CH₃Al(O)OCH₃ + CH₃. The barrier predicted for the former was found to be too high for combustion initiation under the ambient condition. The latter, however, may play a key role in initiating the hypergolic reaction of TMA in the air. Rate constants for both channels have been calculated for the temperature range of 300 – 2000 K. The pressure-independent rate constant for the TMA + O₂ reaction via the loose transition state is predicted to be k(T) = 3.05 × 10^-21T^3.003 exp(-3226.1/T) cm³ molecule^-1 s^-1; this result gives the half-life of TMA in air under the ambient condition to be as short as 1.7 x 10^-2 s, which is sufficiently short for the hypergolic combustion initiation without even considering the ensuing rapid radical chain reactions.

在CCSD（T）/ 6-311 ++ G（3df ）上对重要的工业化合物（CH ₃）₃ Al（TMA）与O ₂反应的机理和动力学进行了理论研究。2p）// B3LYP / 6-311 ++ G（3df，2p）水平结合常规过渡状态理论（TST）计算。反应的势能面（PES）表示TMA + O ₂系统有两条途径导致形成不同的产物对：第一个通过具有16.9 kcal / mol的高能垒的紧密过渡态而产生（CH ₃）₂ AlO ₂ + CH ₃另一种则经历了类似能量的低得多的6.8 kcal / mol的松散漫游状过渡态，生成了CH ₃ Al（O）OCH ₃ + CH ₃。发现对于前者预测的屏障对于环境条件下的燃烧启动而言过高。然而，后者可能在引发空气中TMA的高声反应中起关键作用。在300 – 2000 K的温度范围内，已计算出两个通道的速率常数。TMA+ O ₂通过松散过渡态的反应的独立于压力的速率常数预计为k（T）= 3.05×10 ^-21 Ť ^3.003 EXP（-3226.1 / T）厘米³分子^-1s ^-1 ; 该结果使得在环境条件下，TMA在空气中的半衰期短至1.7 x 10 ^-2 s，这对于超高分子量燃烧的起始是足够短的，甚至不考虑随后的快速自由基链反应。