As a strong base NaH is a base of wide scope and utility in organic chemistry. As a
superbase, it is capable of
deprotonating a range of even weak
Brønsted acids to give the corresponding sodium derivatives. Typical "easy" substrates contain O-H, N-H, S-H bonds, including
alcohols,
phenols,
pyrazoles, and
thiols. NaH notably deprotonates carbon acids (i.e., C-H bonds) such as 1,3-
dicarbonyls such as
malonic esters. The resulting sodium derivatives can be alkylated. NaH is widely used to promote condensation reactions of carbonyl compounds via the
Dieckmann condensation,
Stobbe condensation,
Darzens condensation, and
Claisen condensation. Other carbon acids susceptible to deprotonation by NaH include sulfonium salts and
DMSO. NaH is used to make
sulfur ylides, which in turn are used to convert
ketones into
epoxides, as in the
Johnson–Corey–Chaykovsky reaction.
As a reducing agent NaH reduces certain main group compounds, but analogous reactivity is very rare in organic chemistry. Notably
boron trifluoride reacts to give
diborane and
sodium fluoride: : Si–Si and S–S bonds in
disilanes and
disulfides are also reduced. A series of reduction reactions, including the hydrodecyanation of tertiary nitriles, reduction of imines to amines, and amides to aldehydes, can be effected by a composite reagent composed of sodium hydride and an alkali metal iodide (, M = Li, Na).
Hydrogen storage Although not commercially significant, sodium hydride has been proposed for hydrogen storage for use in
fuel cell vehicles. In one experimental implementation, plastic pellets containing NaH are crushed in the presence of water to release the hydrogen. One challenge with this technology is the regeneration of NaH from the NaOH formed by hydrolysis. ==Practical considerations==