卤素的苯甲酸乙酯电化学微萃取的量子化学研究

Molecular Mechanism Study of Electrochemical Micro-Extraction of Hylogen with Ethyl Benzoate

以AM1半经验量子化学方法研究了卤素分子电化学微萃取进入苯甲酸乙酯有机相的分子机理.卤素阴离子在电极上氧化成为卤素分子,卤素分子萃取进入苯甲酸乙酯有机相,萃取过程取决于卤素分子与苯甲乙酯分子间相互作用.AM1半经验量子化学方法计算了卤素分子与苯甲酸乙酯分子作用前后,分子轨道和相应的热力学参数.分子萃取决定于局部分子间的局部作用能(Br2—EB>I2—EB>Cl2—EB)而不是体系的焓变;卤素分子的还原性取决于与苯甲酸乙酯作用前后最低空轨道的能量的变化,萃取后最低空轨道能量下降,具有相转移电化学催化作用,预测结果与实验结果一致.

The molecular mechanism of electrochemical micro-extraction of hylogen was studied by semi-empirical quantum chemical AM1 method. Hylogen ions are oxidized into hylogen molecules electrochemically, and extracted into ethyl benzoate organic phase. The extraction processis determined by the interactions between hylogen molecules and ethyl benzoate. The stable configurations of the two molecules were optimized, and some thermodynamic parameters such as the energies of Lowest Unoccupied Molecular Orbital （LUMO）, Highest Occupied Molecular Orbital （HOMO）, heat of formation of molecules and systems, coulombic interaction, and total of electronic and nucler energies were calculated by AM1 software. Compared the calculated results with experimental ones, it was found that the molecular extraction is determined by the local molecular interaction, but the reduction behavior determined by the LUMO, which refer to the phase transfer catalysis process.