Negative polarity atmospheric pressure chemical ionization of selected chlorinated hydrocarbons (tetrachloromethane CCl₄ and hexachloroethane C₂Cl₆, dichloromethane CH₂Cl₂, trichloromethane CHCl₃, 1,1,1,2-tetrachloroethane 1,1,1,2-C₂H₂Cl₄, 1,1,2,2-tetrachloroethane 1,1,2,2,-C₂H₂Cl₄ 1,1,2-trichloroethane 1,1,2-C₂H₃Cl₃, and 1,1,2-trichloroethane 1,1,2-C₂HCl₃) was studied using ion mobility spectrometry (IMS) and IMS combined with time-of-flight mass spectrometer (IMS-TOF MS) techniques, in the dry air and at two different drift gas temperatures (323 and 373 K). The ionization was performed using the O₂^–CO₂(H₂O)_0,1 reactant ions (RIs), and the dominant ionization reaction was the dissociative electron transfer. The ionization resulted in the appearance of Cl^– ions for all substances and [O₂H..Cl]⁻ ions, which were absent in the case of perchlorinated substances. The quantum-chemical calculations at the density functional theory level of theory using the ωB97X-D/aug-cc-pVTZ method were performed to calculate the thermochemical data (heats of formations, electron affinities, reaction enthalpies) for RIs, neutral substances, neutral fragments, and the anionic fragments. The calculations supported the experimental observations regarding the endothermicity of the Cl^– channel for all substances and the exothermicity of the [O₂H..Cl]⁻ channel for the tetrachloro- and trichloroethanes.

中文翻译：

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离子淌度谱 (IMS) 和 IMS-MS 技术研究氯化烃的负大气压化学电离

_{所选氯化烃（四氯甲烷 CCl 4}和六氯乙烷 C ₂ Cl ₆、二氯甲烷 CH ₂ Cl ₂、三氯甲烷 CHCl ₃、1,1,1,2-四氯乙烷 1,1,1,2-C ₂ ）的负极性大气压化学电离H ₂ Cl ₄、1,1,2,2-四氯乙烷 1,1,2,2,-C ₂ H ₂ Cl ₄ 1,1,2-三氯乙烷 1,1,2-C ₂ H ₃ Cl ₃和1,1,2-三氯乙烷 1,1,2-C ₂ HCl ₃) 使用离子迁移谱 (IMS) 和 IMS 结合飞行时间质谱 (IMS-TOF MS) 技术，在干燥空气和两种不同的漂移气体温度（323 和 373 K）下进行了研究。使用 O ₂ ^– CO ₂ (H ₂ O) _0,1反应物离子 (RIs) 进行电离，主要的电离反应是解离电子转移。电离导致所有物质都出现 Cl ^–离子和 [O ₂ H..Cl] ^-离子，在全氯物质的情况下不存在。使用 ωB97X-D/aug-cc-pVTZ 方法在理论的密度泛函理论水平进行量子化学计算，以计算 RI、中性物质、中性物质的热化学数据（形成热、电子亲和力、反应焓）碎片和阴离子碎片。计算支持关于所有物质的 Cl ^-通道的吸热性和四氯乙烷和三氯乙烷的 [O ₂ H..Cl] ^{-通道的放热性的实验观察。}