This colourless solid is prepared by the reaction of selenium with a solution of sodium in liquid ammonia at −40 °C.[3] Alternatively, sodium selenide can be prepared by the reaction of gaseous hydrogen selenide with metallic sodium at 100 °C.
Reactions
Like other alkali metal chalcogenides, this material is highly sensitive to water, easily undergoing hydrolysis to give mixtures of sodium biselenide (NaSeH) and hydroxide. This hydrolysis occurs because of the extreme basicity of the Se2− ion.
Na2Se + H2O → NaHSe + NaOH
Similarly, sodium selenide is readily oxidized to polyselenides, a conversion signaled by off-white samples.
^Bonneau, Philippe R.; Jarvis, Robert F.; Kaner, Richard B. (1992). "Solid-state metathesis as a quick route to transition-metal mixed dichalcogenides". Inorganic Chemistry. 31 (11): 2127–2132. doi:10.1021/ic00037a027.
^Brauer, G. ed. (1963) Handbook of Preparative Inorganic Chemistry, 2nd Ed., Academic Press, NY., Vol. 1. p. 421.