Technical report abstract: Sodium hydride and triethylborane react to form sodium triethylhydroborate, NaBH(C2H5)3. This compound, a liquid at rooom temperature, was found to be soluble in hexane and mineral oil. A study was made of the thermal decomposition of sodium triethylhydroborate and its behavior toward boron trifluoride, boron trichloride, methyl borate, carbon dioxide, silane, and ethylene. Sodium triisopropoxyhydroborate, NaBH(OC3H7)3, was prepared and also found to be soluble in hexane and mineral oil. The reactions of this compound with methyl borate, triethylborane, silicon tetrachloride, and boron trichloride were investigated.