哈龙1211分子在外电场中的物理特性研究

Study on the physical characteristics of the Halon-1211 under the electrical fields

采用密度泛函理论,在B3LYP/6-311++G(d,p)基组水平上对分子进行优化,研究了在不同外电场下,哈龙1211分子的键长、体系总能量、偶极矩、能级、能隙、电荷分布和红外光谱的变化规律.计算结果表明,电场方向不同,键长的变化趋势也不同.随着外电场(-0.02 a.u.-0.03 a.u.)的增加,C-Br间的键长随x轴方向电场的增加可能先趋于断裂,而C-Cl间的键长随y轴方向电场的增加可能最先趋于断裂,这对利用外电场解离哈龙1211分子有着重要意义.体系总能量和能隙随着外电场的增加先增大后减小,而偶极矩的变化趋势相反.另外,随着电场的增加,红外光谱的最强峰先发生蓝移再发生红移.

The molecular structure of Halon - 1211 is optimized using the density function theory on the level of B3LYP/6-311 ＋ ＋ G（d,p）. The effects of external fields on the bond lengths, the system energy, the dipole moment, the energy level, the highest occupied molecular orbital -lowest unoccupied molecular orbital （HOMO -LUMO） gap, the charge distribution and the infrared spectrum of Halon- 1211 are studied. The results indicate the changing tendency of the bond lengths varies according to the direction of the fields. As the external electric field increases from - 0.02 to 0. 03 a. u. the bond （ C - C1） applied electrical field of x - axis could tend to be broken, while the bond （ C - Br） applied electrical field of y - axis could tend to disciate. It offers sig- nificant reference for breaking Halon - 1211 using external electrical fields. The system energy, the HOMO energy level and LUMO energy level increase firstly and then decrease with the increase of electric field, but the dipole moment shows an opposite trend. At the same time, the strongest peak of the spectra exhibits blue shift and then red shift.