Reaction of diborane with potassium, rubidium, and cesium borohydrides in diglyme

1. Diborane is absorbed by suspensions of the borohydrides of potassium, rubidium, and cesium in diglyme, with their simultaneous transition into solution. The solubility of the MBH4 increases in the order K to Cs. The ratio of the dissolved diborane and borohydride molecules corresponds to the formula MBH4 ·xBH3, where x ≈ 2. 2. The borohydrides separate from solution when precipitated with diethyl ether.