Tetraethylammonium tetrafluoroborate

(1), boric acid refining:

Specific operations are as follows:

Industrial boric acid dissolved in boiling deionized water, and then filtered, the filtrate is reduced to room temperature, crystallization, filtration, and washed with deionized water, and then re-dissolve the cake in boiling deionized water, cooling, crystallization, and repeat the three times the recrystallization process, you can get the refining of boric acid, the yield of 42-50%;

(2) Fluoroboric acid preparation:

Weigh 100ml 40% (wt) hydrofluoric acid into the polytetrafluoro material with stirring, condensation reflux device and cooling coils in the reactor, while stirring in batches in 1 hour to add 34.5 grams of boric acid, the reaction temperature of 35 C, after adding boric acid continue to stir for half an hour, and then stop stirring and let it stand for 2 hours at room temperature, filtering! Remove the intolerable impurities, that is, 33% concentration of aqueous fluoboric acid solution;

(3) tetraethylammonium fluoroborate synthesis and refining:

Weigh 25g tetraethylammonium chloride and 50g butanol added to polytetrafluoro material in the reactor at 30 , 2 hours of slow droplets of aqueous fluoboric acid, and then warm to 40 to continue to react for 2 hours, the end of the reaction, reduced pressure Concentrate, and add 25g of butanol at room temperature, stirring for 2 hours for crystallization, filtration, and butanol wash to remove the mother liquor with impurities, the wet powder obtained - tetraethylammonium tetrafluoroborate 40g; tetraethylammonium tetrafluoroborate wet powder into a container with 150ml ethanol solution with a condensation reflux device, warming boiling After the solids were all dissolved, the temperature was lowered while stirring, cooled to room temperature, and crystallized, filtered, and washed with ethanol solution at room temperature, the recrystallization process was repeated twice, and after vacuum drying, 21g of qualified ammonium tetraethyl tetrafluoroborate product was obtained with a yield of 64.2% (mol).