红外技术, 2019, 41 (10): 982, 网络出版: 2019-12-05
典型场地有机污染物多环芳烃的红外光谱特征
Infrared Spectra of Polycyclic Aromatic Hydrocarbons from Typical Sites
摘要
采用量子化学从头算的方法计算了多环芳烃萘、苊烯的红外谱图, 比较了理论计算与实验实测所得的萘、苊烯红外谱图结果。在此基础上, 结合 IR光谱解析方法对萘、苊烯的红外谱峰基团进行归属和认定。结合分子轨道理论以及 π-π共轭效应理论, 分析了多环芳烃萘与苊烯的吸光强度以及谱峰位移的差异。得出结论: ①随着共轭体系的增大, 多环芳烃苊烯的吸光强度相较于萘明显增大。 ②共轭效应的增强, 使得苊烯苯环上的 C=C伸缩振动频率向低频率处位移, 而与苯环相连的 C-C伸缩振动向高频率处位移。这一结论可进一步应用于红外光谱多环芳烃的鉴别, 为典型场地有机污染物的在线监测设备研制提供理论基础。
Abstract
The infrared spectra of polycyclic aromatic hydrocarbons, namely, naphthalene and acenaphthylene, were determined using the quantum chemical ab initio method. Then, the results of the theoretical and experimental measurements of naphthalene and acenaphthylene were compared. On this basis, combined with the infrared spectrum analysis method, the infrared peak groups of naphthalene and acenaphthylene were assigned and identified. Combined with the molecular orbital theory and π-π conjugation effect theory, the differences in the absorbance and peak shift of naphthalene and acenaphthylene were analyzed. The conclusions were as follows: ①With the increase in the conjugated system, the absorption intensity of terpenes was significantly higher than that of naphthalene. ②The enhancement of the conjugation effect caused the C=C stretching vibration frequency on the terpene benzene ring to shift to a low frequency and the C-C stretching vibration connected to the benzene ring to shift to a high frequency. This conclusion can be further applied to the identification of polycyclic aromatic hydrocarbons in the infrared spectrum, which can provide a theoretical basis for the development of online monitoring equipment for organic pollutants in typical sites.
王雯倩, 万其进, 陈奕云, 王新智, 陈敏, 余珮珩, 万远. 典型场地有机污染物多环芳烃的红外光谱特征[J]. 红外技术, 2019, 41(10): 982. WANG Wenqian, WAN Qijin, CHEN Yiyun, WANG Xinzhi, CHEN Min, YU Peiheng, WAN Yuan. Infrared Spectra of Polycyclic Aromatic Hydrocarbons from Typical Sites[J]. Infrared Technology, 2019, 41(10): 982.