Dymanic properties of partially halogenated alkenes and alcohols

Abstract

Reaction of $O(^3P)$ Atoms with $CF^2=CXY$ (X, Y=H, F, Cl, Br): Discharge Flow-Chemiluminescence Imaging Technique The chemiluminescence imaging technique has been introduced to obtain kinetic properties in the discharge flow system. The decay curve of $O(^3P)$ atom concentration in the reaction of $O(^3P)$ with partially halogenated olefins, $CF_2=CXY$ (X, Y=H, F, Cl, Br), has been monitored using $NO_2$ chemiluminescence imaging via chemical titrations of $O(^3P)$ with $NO$ molecules from the entire reaction zone using a charge-coupled device camera. The observed rate coefficients of $O(^3P)$ with $CH_2=CH_2$, $CF_2=CHF$, $CF_2=CHCl$, $CF_2=CHBr$, $CF^2=CFBr$, and $CF_2=CBr_2$ at 298.2 K are (6.81 ± 0.66), (4.05 ± 0.20), (3.21 ± 0.41), (2.16 ± 0.18), (3.39 ± 0.23) and (1.40 ± 0.27) $10^{-13} ㎤ molecule^{-1} s^{-1}$, respectively. Comparative studies of the present system with the conventional flow method have been also performed, and have confirmed that the present method gives resonably good results and can therefore be considered as an acceptable new tool for kinetic studies. Intracluster Ion-Molecule Reactions within 1,1-Difluoroethylene Homocluster Intracluster ion-molecule reactions within 1,1-difluoroethene homocluster ions have been studied by electron-impact quadrupole mass spectrometry. When $CH_2CF_2$ seeded in helium is expanded and ionized by electron impact, the ion-molecule association (polymerization) reaction occurs in the cluster ions and $(CH_2CF_2)_n^+$ ions ($n ≥ 1$) and $(CF_2CH_2)_qX^+$ ions (X= fragment species, $q ≤ n$) are formed. The higher intensity of $(CH_2CF_2)_q^+$ ions over $(CH_2CF_2)_2^+$ ions (q=3, 4) at low electron impact energy region (＜ 39 eV) suggests that trimer and tetramer ions are more stable than dimer ions in the low-energized cluster ions regime. The evidence for the stable formation of these ionic species is found from the observation of the fragment pattern and semi-empirical calculation. F-shift reaction pat...