Superbase
In
chemistry, a
superbase is an extremely strong
base. There is no commonly accepted (see
superacid) standard for "stronger than what?" although most chemists will happily consider
sodium hydroxide as their 'benchmark' base just as they use
sulfuric acid as their 'benchmark' acid.
There are three main classes of superbases:
organic,
organometallic, and
inorganic.
An organic superbase is
1,8-Bis(dimethylamino)naphthalene (Proton-sponge).
In organic synthesis, the
Lochmann-Schlosser base, i.e. the combination of
n-butyllithium and
potassium tert-butoxide, is commonly referred to as a superbase. In this combination of reagents the tertiary alcoholate serves to complex the
lithium ion, thus freeing the carbanion from its close association with the metal ion. Other such systems are collectively called
harpoon bases.
Inorganic superbases are typically salts with highly charged, small negative ions, e.g.
lithium nitride, which has extreme negative charge density and so is highly attracted to the aqueous
hydronium ion.
*
Superacid
