Swarts Reaction: Swarts Fluorination Method for Preparation of Fluorides

Ans: Higher alkyl halides (R-Cl) react with lower metal halides (AgF) to generate lower alkyl halides in this reaction (R-F). F ion cannot displace Cl/Br if heavy metal fluoride is not used. The reaction will either not occur or will result in the formation of another chemical.

Ans: Acetone is used as the solvent. The mechanism of the Swarts reaction is simple: a new carbon-fluorine bond is created when the metal-fluorine connection is destroyed.

Ans: CH₃CH₂CH₂Cl + AgF --------→ CH₃CH₂CH₂F + AgCl

Propyl Chloride reacts with Silver Fluoride to give Fluoropropane. A heavy metal fluoride is used due to the fact that a light metal fluoride won’t give out the same reaction.

Ans: SN₂ reaction is the nucleophilic substitution where one bond is broken and another is formed in synchronization. Swarts reaction involves the breakdown of metal and fluorine bond and the formation of bond between carbon and fluorine. Thus, one halogen atom is replaced by another. Due to this reason, Swarts reaction is an SN2 reaction.

Ans: If we use NaF in the reaction with chloroalkane, NaCl is obtained which is readily soluble in water, and there won’t be any further reaction. Since F- is much more electronegative then Chlorine and has a smaller atomic radius, the extent of hydration is much higher. As a result, the nucleophility of F- decreases and the rate of SN₂ decreases. The reaction produces low yield, therefore NaF is not used in the reaction.

Ans: Dry Acetone is used as a solvent as it is a polar aprotic solvent. In the acetone medium NaBr and NaCl are insoluble due to the repulsion of the negative charge on Oxygen with the negative charge on Chlorine or Bromine atom. Therefore, NaCl and NaBr are easily precipitated in the solvent. Hence, for all the above reasons Acetone is used as the solvent.

Ans: Swarts reaction is an SN₂ reaction and F- is the nucleophile. Among the three, bromine is a good leaving group while fluorine is a weak leaving group due to its high charge density. Hence, the rate of 2-bromo propane is higher than that of 2-chloro propane and 2-fluoro propane.

2-bromopropane > 2-chloropropane > 2-fluoropropane

Ans: Swarts reaction is an SN₂ reaction. Due to steric crowding in 1-chloro-2-methyl propane, SN₂ reaction is not possible, while steric crowding is absent in 1-chloro propane. Hence, 1-chloro propane has a higher rate than that of 1-chloro-2-methyl propane.

Ans: Swarts reaction is an SN₂ reaction, where F- ion is used as the nucleophile. In 1-chloro propane, the carbon atom attached to the chlorinated carbon is sp3 hybridized, while in 3-chloro-prop-1-ene the double bonded carbon attached to the chlorinated carbon is sp2 hybridized.

• Due to the +I effect of sp3 hybridized carbon, the positive charge on Chlorinated carbon decreases.
• Hence nucleophilic attack is not helped.
• After breaking the C-Cl bond in 3-chloro-prop-1-ene the pi bond overlaps with the p-orbital of chlorinated carbon and due to that the transition state is more stable or has less transition energy.
• Hence, the rate of Swarts reaction of 1-chloro propane is less than that of 3-chloro-prop-1-ene.

Ans. The difference between Finkelstein Reaction and Swarts Reaction are as follows:

Ans. Freons are fluorinated aliphatic organic compounds. They are used in the industries and commercially. They are constituted by fluorine and carbon. Apart from that they also contain hydrogen, chlorine or bromine. CFCs and HCFCs are two prominent examples. They are used as refrigerants due to their colorlessness, colorlessness, less toxicity and corrosiveness.