Under an argon atmosphere, 0.80 g (0.0045 mol, 1 equivalent) of 4-bromoaniline and 8 mL of methanol were added to a dry reaction flask to obtain a homogeneous solution with a concentration of approximately 0.5 M. The resulting reaction solution was cooled to approximately -20°C in a liquid nitrogen/acetonitrile cold bath. Boron trifluoride diethyl ether (1.38 mL, 1.59 g, 0.0112 mol) was slowly added dropwise to the above reaction mixture, followed by the addition of butyl nitrite (0.80 mL, 0.69 g, 0.0067 mol) over 10–15 minutes. The resulting reaction mixture was allowed to slowly rise to room temperature, during which a significant solid precipitation was observed (because the diazonium tetrafluoroborate product is not readily soluble in methanol after 2 hours). The resulting reaction mixture was filtered under vacuum to separate the precipitated solid. The filter cake was then washed with cold diethyl ether solution, separated, and dried under vacuum to obtain 4-Bromobenzenediazonium tetrafluoroborate.
4-Bromobenzenediazonium tetrafluoroborate was used in preparation of surface modified Au(111) electrode, 1-(4-bromophenyl)-3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodec-1-ene.
