1,1,2,2,3,3,4,4-octafluoro-1,4-diiodobutane

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a four necked flask equipped with a thermometer, a reflux condenser, a dropping funnel and a stirrer, 190 g (0.7 mole as SO3) of fuming sulfuric acid containing 30% of SO3 were charged and were heated at 85° C. and then 100 g (0.22 mole) of 1,4-diiodoperfluorobutane having the formula I(CF2)4I were added dropwise to the flask. The reaction was conducted while maintaining the temperature in the reactor at 80° to 90° C. The collection and the separation of the product were conducted in accordance with the process of Example 4. As a result, the conversion was 52% and perfluorotetrahydrofuran (62% yield) and perfluoro- γ-butyrolactone (7% yield) were obtained based on the starting material. were charged while maintaining the temperature in the reactor at 80° to 90° C The collection the separation of the product

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a four necked flask equipped with a thermometer, a reflux condenser and stirrer, 310 g (2.3 moles as SO3) of fuming sulfuric acid containing 60% of SO3 and 105 g (0.23 mole) of 1,4-diiodoperfluorobutane of the formula I(CF2)4I were charged and heated. The reaction was conducted while maintaining the reaction temperature of 60° to 70° C. The collection and the separation of the reaction product was conducted in accordance with the process of Example 4. As a result, 23 g (47% yield) of perfluorotetrahydrofuran were obtained as a fraction having a boiling point of 1° C., and perfluoro- γ-butyrolactone (10% yield) and perfluorosuccinic difluoride (5% yield) were obtained as another fraction. were charged heated while maintaining the reaction temperature of 60° to 70° C The collection the separation of the reaction product

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a four necked flask equipped with a thermometer, a reflux condenser, a dropping funnel and a magnetic stirrer, 4950 g (18.5 moles as SO3) of fuming sulfuric acid containing 30% of SO3 were charged. The flask was heated to 85° C. and then, 990 g (2.2 moles) of 1,4-diiodoperfluorobutane having the forumla I (CF2)4I were added dropwise to the flask. The reaction was conducted for 6 hours while maintaining the temperature in the reactor at 85° to 95° C. The reaction mixture discharged from the reflux condenser, was passed through a gas washing bottle containing concentrated sulfuric acid and was collected in a flask cooled with a dryice-ethanol coolant. The collected reaction products in the flask were separated by distillation whereby 247 g of a fraction of a boiling point of 18° C. were obtained. According to F19NMR analysis of the fractions, the fraction having a boiling point of 18° C. consisted of 200g (yield of 47%) of perfluoro- γ-butyrolactone and 47 g (yield of 11%) of perfluorosuccinic difluoride. Another fraction having a boiling point of 1° C., 45 g (yield of 11% ) of perfluoroetrahydrofuran was also obtained. were charged while maintaining the temperature in the reactor at 85° to 95° C washing bottle containing concentrated sulfuric acid was collected in a flask cooled with a dryice-ethanol coolant The collected reaction products in the flask were separated by distillation whereby 247 g of a fraction of a boiling point of 18° C. were obtained

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The procedure of Example 17 was followed, except solvent and initiator were varied. Due to the well-known unsuitability of CH2Cl2 as a solvent in regular free radical polymerization systems, including AIBN case, the solvent was changed to acetonitrile. After adding 0.3 g of AIBN, 0.8 g of I(CF2)4I, 3.0 g of CF2═CFCH2CH2OSi(CH3)3, and 30 ml of acetonitrile in a 70 ml stainless autoclave equipped with a magnetic stirrer, 20 ml of VDF and 5 ml of HFP were introduced into the reactor under vacuum by condensing the monomers at liquid nitrogen temperatures. The autoclave was warmed to room temperature gradually and then immersed in an oil bath at 70° C. for 20 hours. After recovering the unreacted monomers, clear solution was observed, and only trace amount (<0.1 g) of white powder was obtained after removing the volatiles. equipped with a magnetic stirrer 20 ml of VDF and 5 ml of HFP were introduced into the reactor under vacuum by condensing the monomers at liquid nitrogen temperatures After recovering the unreacted monomers, clear solution

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The procedure of Example 6 was followed, except solvent and initiator were varied. Due to the well-known unsuitability of CH2Cl2 as a solvent in regular free radical polymerization systems, including AIBN case, the solvent was changed to acetonitrile. After adding 0.3 g of AIBN, 0.8 g of I(CF2)4I, 3.0 g of CF2═CFCH2CH2Si(CH3)2H, and 30 ml of acetonitrile in a 70 ml stainless autoclave equipped with a magnetic stirrer, 20 ml of VDF and 5 ml of HFP were introduced into the reactor under vacuum by condensing the monomers at liquid nitrogen temperatures. The autoclave was warmed to room temperature gradually and then immersed in an oil bath at 70° C. for 20 hours. After recovering the unreacted monomers, clear solution was observed, and only trace amount (<0.1 g) of white powder was obtained after removing the volatiles. equipped with a magnetic stirrer 20 ml of VDF and 5 ml of HFP were introduced into the reactor under vacuum by condensing the monomers at liquid nitrogen temperatures After recovering the unreacted monomers, clear solution