in hexane byproducts: LiCl, (CH3)2NH; under N2, TaCl5, LiN(CH3)2, LiNHC(CH3)3 in hexane were stirred for 48 h; mixt. was filtered, soln. was evapd., residue was sublimed, product wasrecrystd. from hexane; elem. anal.;

in hexane to Ta(N(CH3)2)5 in hexane was added t-BuNH2, mixt. was stirred for 60 h; solvent was evapd., residue was sublimed, recrystd. from hexane (-35°C);