Caesium hydride or cesium hydride is an inorganic compound of caesium and hydrogen with the chemical formula . It is an alkali metal hydride.It was the first substance to be created by light-induced particle formation in metal vapor,[1] and showed promise in early studies of an ion propulsion system using caesium.[2] It is the most reactive stable alkaline metal hydride of all. It is a powerful superbase and reacts with water extremely vigorously.
The caesium nucleus in CsH can be hyperpolarized through interactions with an optically pumped caesium vapor in a process known as spin-exchange optical pumping (SEOP). SEOP can increase the nuclear magnetic resonance (NMR) signal of caesium nucleus by an order of magnitude.[3]
It is very difficult to make caesium hydride in a pure form. Caesium hydride can be produced by heating caesium carbonate and metallic magnesium in hydrogen at 580 to 620 °C.[4]
At room temperature and atmospheric pressure, CsH has the same structure as NaCl.