3 hexafluoro 2 propanol

The diazonium salt of HFHPB-N2⁺ was synthesized according to a previous report42 (link). 2-(4-Aminophenyl)-1,1,1,3,3,3-hexafluoro-2-propanol (0.200 g, Alfa Aesar) was dissolved in a 50 ml round bottom flask with dry THF (5 ml) under a N₂ atmosphere. This solution was added dropwise to boron trifluoride etherate (2 equiv.) in a round bottom flask cooled to −5 °C under N₂. Isoamyl nitrite (1.6 equiv.) was then added dropwise to the mixture with a syringe, and a solid subsequently formed. The mixture was allowed to stir for 30 min at −5 °C before it was allowed to return to room temperature. The solid was then filtered, and the filtered white power was washed with small amount of cold Et₂O to yield a white solid after drying: characterization data for hexafluoroisopropylbenzenediazonium tetrafluoroborate; ¹H NMR (500 MHz, CO(CD₃)₂, δ), ppm δ = 8.53 (d, Ar-H, 2H), 9.09 (d, Ar-H, 2H).

For the synthesis of HFHPB daizonium salts, 0.9 g 2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoro-2-propanol (2.9 mmol, Alfa Aesar) was dispersed in 10 ml distilled tetrahydrofuran (THF) in a 50 ml round flask and cool to −5 °C. 0.6 ml isoamyl nitrite (4.6 mmol, 1.6 equiv.) was added to the HFHPB derivative solution using a drop wise method and stirred for 10 min. After stirring, 0.72 ml boron trifluoride etherate (5.8 mmol, 2 equiv.) was added to the flask and incubated for 12 h at 60 °C. All steps were performed in a N₂ atmosphere under an ice bath (−5 °C). The yellow solid was filtered and washed by Et₂O until it produced a white solid product.