五个生成环氧乙烷的反应的热力学预测(英文)

运用密度泛函方法B3LYP/6-311+G(2df,2p)//B3LYP/6-31G(d)对文献1]提出的Titan大气中可能生成环氧乙烷的五个反应在不同的温度和压强条件下进行了热力学计算和分析,发现:a)所有反应的反应焓变和吉布斯自由能变都小于零,反应都是放热反应,具有较大的自发反应趋势;在低温下反应的平衡常数很大,数据显示反应在低温下正向进行的自发反应趋势更大。b)对比生成环氧乙烷的同素异构体:乙醛和乙烯醇的计算结果,可以预测到在Titan大气的低温环境中自然合成环氧乙烷是很有可能的.

Calculations of the Thermodynamic Properties of Five Reactions Producing Oxirane

In this paper, the thermodynamic properties of reactions that would lead to oxirane formation in Titan's atmosphere: H2CCH2 + O(1D)→C2H4O, H2CCH2 + O(3P)→C2H4O, CH+3 + C2H5OH→C2H5O+ + CH4, C2H5O+ + e-→C2H4O + H and C2H5 + O→C2H4O + H have been calculated and discussed by means of Density Function Theory at the B3LYP/6-311 + G(2df,2p)//B3LYP/6-31G(d) level. The geometries of the reactants and products of reactions have been optimized, the energies of reactions have been computed. The analysis of the results shows that:(a) The Free Energies of reactions are negative. It means that reactions could produce oxirane spontaneously in Titan' s environment. (b) The converted temperature of reaction ( 1 ), ( 2 ) and (5) is 5457K,2854K and 4091K respectively. It is concluded that all of these reactions might be pathwaysfor the synthesis of oxirane in Titan's atmosphere.