56 ALIPHATIC FLUORINE COMPOUNDS From these experiments it is clear that, in the reaction of a poly-chloroparaffin with antimony trifluoride activated by a pentavalent antimony salt: 1. —CC1 3 groups are most reactive; they are converted to —CC1 2 F and —CC1F 2 groups, but rarely to —CF 3 groups. 2. —CHC1 2 groups are changed slowly to —CHC1F groups and with greater difficulty to —CHF 2 groups. 3. —CH 2 C1 and —CHC1— groups are not affected. 4. The presence of fluorine decreases the ease of replacement of halogen attached to an adjacent carbon atom, or prevents such replace-ment. 5. Side reactions and decompositions increase as the hydrogen content of the molecule increases. Hydrogen fluoride alone undergoes exchange reactions only with very reactive organic halides. However, .because it reacts with antimony chloride to form antimony fluoride and hydrogen chloride, 34 it can be used to transform a large amount of organic halide*to the fluoride with the aid of only small .amounts of antimony salts. This is the method used
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This note was uploaded on 11/20/2011 for the course CHM 2210 taught by Professor Reynolds during the Fall '01 term at University of Florida.