Perhaps thats the problem- you're reading a borane article! the one I am referring to is Attwood Bott el Al 1991, Inorg.Chem, p3792-3 which describes the synthesis of the gallane TMEDA adduct by a reaction of the gallane  trimethylamine adduct in Et2O, basically, add TMEDA solution to gallane adduct solution slowly, wait a while, get rid of ether, recrystallise, jobs a good'un as we say in the old country. Did some similar myself once with low valent indium/gallium compounds, but never got a paper out of it sadly, my gunk never recrystallised.