sugar charcoal in neat (no solvent) heating to 700 - 800°C;; sublimation;;

in neat (no solvent) heating;;

hydrogen bromide in diethyl ether; n-heptane byproducts: LiCl, B2H6, H2; (Ar); ZrCl4 and LiBH4 were shaken in a Schlenk tube, dissolving in n-heptane at -78°C in vacuo, HBr was bubbled for 6 h at ambient temp.,stirring 12 h under HBr atmosphere; filtn., washed with n-heptane, dried in vacuo, sublimed at 190°C for 15 h, elem. anal.;

N2-stream loaded with Br2 is passed over a mixt. of dry HfO2 with the 3-fold amount sugarcoal at yellow heat;; HfBr4 is condensed by water cooling, sublimation in vacuum;;

in water