Cis-l ,2-Dichloroethylene

Equations (2) and (3) could permit a simple determination of fc 2/A-B, and the authors started their experimental work with this objective in mind. The values of Ez and A3 for the C2H2CI3 radicals were known from the work of Ayscough et al. (7) in which they applied the rotating sector technique to the photochlorination of cis-l,2-dichloroethylene and found logio A3 (1. mole"1 sec.-1) = 8.7 0.3 and i 3 = 2.7 0.6 kcal. mole-1. In view of these values, and Howlett s conclusion, based on thermal dehydrochlorination studies, that for C2H3CI2 radical A 2 = 1013 sec.-1 and f 2 = 22 kcal. mole-1, no detectable isomerization was expected below 200°C. However, in contrast to this, a concurrent isomerization was easily detectable at 30°C even at a chlorine pressure of 200 mm. A detailed investigation was therefore necessary to explain the reasons for the discrepancy. 

The procedures used most often for preparation of arylsulfonyl acetylenes Involve oxidation of the corresponding ethynyl thio ether. The thio ethers are usually obtained via a two-step sequence beginning with two-fold thiophenoxide displacement of chloride ion from cis-l,2-dichloroethylene, followed by elimination with n-butyl1ithium in the resultant cis-1,2-bisarylthioethylene. Less well known methods involve diazotization of 4-arylsulfonyl-5-aminoisoxazoles, dehydrobrpmination of cis- and trans-2-bromovinyl phenyl sulfone with fluoride ion, and oxidative elimination of - phenylseleno)vinyl sulfones. The method described here, which bypasses the need for strongly basic conditions, is adapted from the work of Bhattacharya, Josiah, and Walton. The simplicity and mildness of the method suggest that it may be broadly useful. 

Volatile organic contaminants such as benzene, carbon tetrachloride, chlorobenzene, o-dichloro-benzene, p-dichlorobenzene, 1,1-dichloroethylene, cis-l,2-dichloroethylene, tra s-l,2-dicholoro-ethylene, dichloromethane, 1,2-dichloroethane 1,2-dichloropropane, ethylbenzene, styrene, tetrachloroethylene, 1,2,4-trichlorobenzene, 1,1,1,-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, toluene, vinyl chloride, and xylenes. 

Dichloroethylene cis-l,2-Dichloroethylene trans 1,2-Dichloroethylene l,3 Dichloro-2-hydroxypropane Dicyandiamide Dicyclohexanol acetylene Dicyclohexyl... 

Figure 16.2.6. Typical chromatogram of class 2 residual solvents using the conditions described for system B and procedure 1. Flame ionization detector. 3 acetonitrile 11 chloroform 13 cyclohexane 16a cis-l,2-dichloroethylene 17 dichloromethane 23 1,4-dioxane 29 hexane 30 2-hexanone 34 methanol 49 pyridine 51 toluene 53 1,1,2-trichloroethylene 54 xylene,ortho,meta,para 58 chlorobenzene 61 tetralin 62 methylcyclohexane 63 nitromethane 64 1,2-dimethoxyethane. [Adapted, by permission, from European Pharmacopoeia, Addendum 2000, pp31 -36.] [Please note that information concerning residual solvents are susceptible to be modified in the successive editions of the European Pharmacopeia.]...

At the reaction temperature of 400 C, dechlorinated products of TCEa consisted of chloroethene (VCM), 1,1-dichloroethylene, trans-1,2- and cis-l,2-dichloroethylene (DCE) for the tested catalysts. However, the main product was changed with types of metal loaded in the catalysts. VCM was the main product in the cases of Ni catalysts (Ni-L-CS, Ni-L-SBA and Ni-E-SBA), while cis-l,2-DCE was a main product for the Mo catalyst (HP318). Since the VCM is a raw material for the PVC production, selectivity for VCM and conversion of TCEa could be used as important factors to compare the catalyst performances. It was observed (Fig. 4 (a)) that the prepared catalysts were deactivated faster than the commercial catalyst. Catalysts prepared using APTES and LIX-984 showed a better life-time than the catalysts prepared using EDTA. It was believed that Ni-L-SBA catalyst was lasted longer than the Ni-L-CS catalyst due to the uniform pore structures. In addition, prepared catalysts showed a better selectivity for VCM than that of commercial catalyst (Fig. 4 (b)). 

Dichloroethylarsine cis-l,2-Dichloroethylene fra s-l,2-Dichloroethylene Dichloroethyl ether 2J7 -Dichloro-3,6-fluorandiol... 

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