摘要
用量子化学从头计算法对Ｈ＋ＮＦ２体系的三重态势能面进行了研究，采用ＭＰ２（ＦＵＬＬ）／６－３１Ｇ（ｄ）方法计算了反应物、产物、过渡态的构型参数和振动频率，然后用Ｇａｕｓｓｉａｎ－２理论计算了各物种的精确能量。用Ｇ２理论计算得到０Ｋ下反应的势垒高度为８６．４ｋＪ／ｍｏｌ，反应热为－２８１．３ｋＪ／ｍｏｌ。反应热结果与实验值非常一致；热动力学计算的结果排除了Ｈ＋ＮＦ２反应在三重态势能面直接产生ＮＦ（Ｘ）的可能。
The triplet potential surface of H+NF 2 reaction has been studied using ab initio molecular methods.The geometries and frequencies for all species are caculated at MP2(FULL)/6-31G(d) level of theory.The energies of all species were futher calculated using Gaussian 2 theory.The best estimate of the heat of reaction is -281 3kJ/mol at 0K, in good agreement with the experimental result, -284 1kJ/mol. The best potential barrier height for this reaction was calculated to be 86 4kJ/mol. The calculated thermodynamic and kinetic results preclude formation of NF(X 3Σ) by the direct reaction of H+NF 2 on the triplet potential surface.
基金
国家自然科学基金
