New stannylboranes were prepared from tetramethylpiperidino dichloroborane or B-bromo-pentamethylborazine with lithium triorganylstannides LiSnR3. Only double stannylation was possible with tmpBCl(2) and LiSnMe3, while tmpBCl(SnPh3) was obtained by employing LiSnPh3. This chloride reacted with LiGePh3 to the stannyl germyl borane tmpB(GePh3)(SnPh3). On the other hand, PhMeNBCl2 and an excess of LiSnMe3 gave the berate Li[B(NMePh)(SnMe3)(3)], which was isolated as a solvate with 4 molecules of THE The compound is present in the solid state as a solvent separated ion pair. The berate Li(H3BSnMe3). 2THF is dimeric In the solid state. Dimerization occurs via two single Li-H-B bridges and a Li-H(B)-Li bridge. The B-Sn bonds in the berates are practically of the same lengths as those in the boranes. In solution all BH bonds of this trihydridoborate are equivalent.