1. A colourless gas, SiH4, which is insoluble in water; d. 1.44 g dm−3; r.d. 0.68 (liquid); m.p. –185°C; b.p. –112°C. Silane is produced by reduction of silicon with lithium tetrahydridoaluminate(III). It is also formed by the reaction of magnesium silicide (Mg2Si) with acids, although other silicon hydrides are also produced at the same time. Silane itself is stable in the absence of air but is spontaneously flammable, even at low temperatures. It is a reducing agent and has been used for the removal of corrosion in inaccessible plants (e.g. pipes in nuclear reactors).
2. (or silicon hydride) Any of a class of compounds of silicon and hydrogen. They have the general formula SinH2n+2. The first three in the series are silane itself (SiH4), disilane (Si2H6), and trisilane (Si3H8). The compounds are analogous to the alkanes but are much less stable and only the lower members of the series can be prepared in any quantity (up to Si6H14). No silicon hydrides containing double or triple bonds exist (i.e. there are no analogues of the alkenes and alkynes).