Thermodynamic Property and Relative Stability of 76 Polybrominated Naphthalenes by Density Functional Theory
Thermodynamic Property and Relative Stability of 76 Polybrominated Naphthalenes by Density Functional Theory
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DOI：
10.1021/je0601154
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发表时间：
2006-11
影响因子：
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通讯作者：
Lifen Yuan;Jing Yu;Zunyao Wang;H. Liu;X. Ju
中科院分区：
文献类型：
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作者：
Lifen Yuan;Jing Yu;Zunyao Wang;H. Liu;X. Ju
在B3LYP/6-31G*水平上对理想气相中萘和75种多溴化萘（PBNs）进行了完全优化计算。根据温度修正计算相应的热力学参数，包括标准焓、标准吉布斯能、标准熵、等容标准热容和标准热能（即分子平移、旋转和振动的零点能量和热能修正的总和）。此外，还讨论了一些热力学参数与溴取代基数目和位置的关系。每增加一个溴原子，标准熵和标准热容分别增加约41 J·mol -1·k -1和17 J·mol -1·k -1，标准热能减少约48 kJ·mol -1。通过设计等速反应，得到了标准生成焓和标准吉布斯生成能。根据相对标准吉布斯生成能的大小，从理论上提出了PBN异构体的相对稳定性。此外，还比较了B3LYP/6-31G*方法和四种半经验方法（AMI、MNDO-d、MNDO和PM3）对pbn的标准生成焓值。
The fully optimized calculation of naphthalene and 75 polybrominated naphthalenes (PBNs) in the ideal gas phase were carried out at the B3LYP/6-31G* level. The corresponding thermodynamic parameters, including standard enthalpy, standard Gibbs energy, standard entropy, standard heat capacity at constant volume, and standard thermal energy (i.e., the sum of zero-point energy and thermal energy corrections for molecular translation, rotation, and vibration), were calculated according to temperature correction. In addition, the dependences of some thermodynamic parameters on the number and the position of bromine substituent are discussed. With each additional bromine atom being introduced to the PBNs, the increments of standard entropy and standard heat capacity at constant volume are about 41 J·mol -1 ·k -1 and 17 J·mol -1 ·K -1 , respectively, and the decrease of standard thermal energy is about 48 kJ·mol -1 . By designing isodesmic reactions, the standard enthalpy of formation and the standard Gibbs energy of formation were obtained. On the basis of the magnitude of the relative standard Gibbs energy of formation, the relative stability of PBN isomers was theoretically proposed in this work. Furthermore, comparison of the standard formation enthalpies values, obtained from the B3LYP/6-31G* method as well as four semiempirical methods (AMI, MNDO-d, MNDO, and PM3), was made for PBNs.