【摘要】 采用Gaussian 03程序中的密度泛函(DFT)方法,在B3LYP/6-31G*水平上对135个多氯咔唑系列化合物(PCCZs)进行了全优化计算,得到了298.15K,1.013×105Pa标准状态下各分子的热力学性质.设计等键反应,计算了PCCZs系列化合物的标准生成热(ΔfH)和标准生成自由能(ΔfG),研究了这些参数与氯原子的取代位置及取代数目(NPCS)之间的关系,结果表明:熵(S),ΔfH,ΔfG与NPCS之间有很强的相关性.并根据ΔfG的相对大小,从理论上求得异构体的相对稳定性的顺序.此外,以Gaussian 03程序的输出文件为基础,采用统计热力学程序计算了PCCZs化合物在200至1800K的摩尔恒压热容(Cp,m),并用最小二乘法求得Cp,m与温度之间的相关方程,发现Cp,m与T,T-1和T-2之间有着很好的相关性.更多还原

【Abstract】 The thermodynamic properties of 135 polychlorinated carbazoles(PCCZ) in the ideal gas state at 298.15 K and 1.013×105 Pa have been calculated at the B3LYP/6-31G level using Gaussian 03 program.The isodesmic reactions were designed to calculate the standard enthalpy of formation(ΔfH) and standard free energy of formation(ΔfG) of PCCZ congeners.The relations of these thermodynamic parameters with the number and position of Cl atom substitution(NPCS) were discussed,and it was found that there existed high correlation between thermodynamic parameters(entropy(S),ΔfH and ΔfG) and NPCS.According to the relative magnitude of their ΔfG,the relative stability order of PCCZ congeners was theoretically proposed.Moreover,using a statistical thermodynamics calculation program based on Gaussian 03 output files,the values of molar heat capacity at constant pressure(Cp,m) from 200 to 1800 K for the PCCZ congeners were calculated,and the temperature dependence relation of them was obtained using the least-squares method,which suggested that there be very good relationships between Cp,m and temperature(T,T-1 and T-2) for almost all the PCCZ congeners.更多还原