Deuterated sodium octahydrotriborate(1-)

Preparation and 11B NMR spectra of perdeuterated and partially deuterated NaB3H8 are reported. Treatment of THF.B3H7 with sodium hydride in diglyme gives NaB3H8 in a quantitative yield. The preparation of deuterated NaB3H8 was performed by using diglyme as the solvent. Treatments of THF.B3H7 and THF.B3D7 with NaD or NaH gave differently deuterated NaB3H8 samples. Spectra data for the NaB3D8 are included. The spectra of the NaB3D7H and NaB3H7D samples indicate informatively the nature of these products. The simple replacement of THF in THF.B3D7 by H- would yield the B3D7H- species. The 2H-spin-decoupled signal of such a species is expected to be a simple doublet signal since the hydrogen atom would be coupled equally to the three boron atoms due to its rapid tautomeric motion within the ion. An octet signal is expected from the NaB3H7D, but this was not the case; apparently an intermolecular H-D exchange reaction had occurred. This exchange reaction proceeds rapidly during the process of the anion formation. The tetrahydrofuran adduct of triborane in the reaction mixture served as the exchange medium. 3 figures