溴乙烷在太阳辐射下解离生成溴自由基，破坏大气臭氧层，因此有必要采取措施对其进行降解。采用密度泛函理论（DFT）方法，在B3LYP/6-31G+（d，p）水平上计算外电场（0~0.028 5 a.u.）下溴乙烷的解离特性和光谱特征。计算结果表明，随着Z轴方向的电场强度从0 a.u.增加到0.028 5 a.u.，分子体系总能量逐渐减小。同时在这一过程中，能隙单调变小，偶极矩逐渐增大。计算的溴乙烷解离势能曲线显示，强度为0.030 a.u.的外电场将使C-Br键断裂。以上这些结果为溴乙烷进行电场降解提供了重要信息。
Bromoethane dissociates and generates the bromine radical under the radiation from the sun, which destroys the atmospheric ozone layer. So, it is necessary to take effective measures to degrade bromoethane. We use the density function theory (DFT) and calculate the dissociation properties and spectral characteristics of bromoethane under the external electric fields (0-0.028 5 a.u.) at the B3LYP/6-31G+(d,p) level. It is showed that the total energy of the molecule decreases as the external field increases from 0 a.u. to 0.028 5 a.u. along the Z-axis. Meanwhile, the energy gap decreases monotonically and the dipole moment increases. It is shown in the potential energy curves that the electric field of 0.030 a.u. is strong enough to break the C-Br bond. The results provide important information for the degradation of bromoethane under external electric fields.
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