Design and Synthesis of a Thermally Stable Organic Electride

An electride has been synthesized that is stable to auto-decomposition at room temperature.
The key was the theoretically directed synthesis of a per-aza analogue of cryptand[2.2.2] in which each of
the linking arms contains a piperazine ring. This complexant was designed to provide strong complexation
of Na+ via pre-organization of a “crypt” that contains eight nonreducible tertiary amine nitrogens. The structure
and properties indicate that, as with other electrides, the “anions” are electrons trapped in the cavities
formed by close-packing of the complexed cations. The isostructural sodide, with Na- anions in the cavities,
is also stable at and above room temperature.