- Method for purifying dichloropentafluoropropanes
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A method of recovering pure dichloropentafluoropropane from a mixture of dichloropentaflouropropane and chloroform (including breaking the azeotropic mixture thereof) involving selectively fluorinating the chloroform to the lower boiling dichloromonofluoromethane and then distilling to separate and recover pure dichloropentafluoropropane.
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- Method for producing dichloropentafluoropropanes
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A method for producing a dichloropentafluoropropane, which comprises reacting dichlorofluoromethane (R21) with tetrafluoroethylene (4F) in the presence of a Lewis acid catalyst for addition reaction to obtain dichloropentafluoropropane, wherein a halide containing at least one element selected from the group consisting of Sb, Nb, Ta, B, Ga, In, Zr, Hf and Ti, or AlBr3, or AlI3, is used as the Lewis acid.
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- 19F nuclear magnetic resonance studies of halogenated propanes
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The relationship between 19F chemical shifts in halogenated propanes and their structures are elucidated using MNDO calculations to determine the population of rotamers.The pairs of atom gauche to a fluorine atom and van der Waals interaction between the two terminal substituents are responsible for the 19F chemical shifts.The differences among chemical shifts in diastereomers are also discussed in terms of the conformation of molecule.
- Tanuma, T.,Ohnishi, K.,Okamoto, H.,Miyajima, T.,Morikawa, S.
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p. 259 - 284
(2007/10/02)
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