in benzene molar ratio Bu4NBH4:Bu4NBBr4=3:1, sealed ampoule, 20 h; product mixt. not sepd., detd. by IR spectroscopy;

in neat (no solvent) byproducts: n-butyl bromide, s-butyl bromide; (n-Bu)4NBBr4 was heated at 240-270°C for 12 h;; volatiles were collected in trap at -80°C, the residue sublimed at 220-240°C/0.05 Torr; second sublimation at 200 °C/0.15 Torr; elem. anal.;;