Methylammonium halides are

organic Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ Chemistry * Organic matter, matter that has come from a once-living organism, is capable of decay or is the product ...

halide In chemistry, a halide (rarely halogenide) is a binary chemical compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative (or more electropositive) than the halogen, to make a fluor ...

s with a

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...

of , where X is Cl for

methylammonium chloride Methylammonium chloride in an organic halide with a formula of CH3NH3Cl. It is an ammonium salt composed of methylamine and hydrogen chloride. One potential application for the methylammonium halides is in the production of perovskite solar ce ...

, Br for

methylammonium bromide Methylammonium bromide in an organic halide with a formula of CH3NH3Br. It is the salt of methylammonium and bromide. It is a colorless, water-soluble solid. The methylammonium halides are precursors to perovskite solar cell A perovskite sol ...

, or I for

methylammonium iodide Methylammonium iodide in an organic halide with a formula of CH3NH3I. It is an ammonium salt composed of methylamine and hydrogen iodide. The primary application for methylammonium iodide, sometimes in combination with other methylammonium ha ...

. Generally they are white or light colored powders.

Applications

These salts are components of

perovskite solar cell A perovskite solar cell (PSC) is a type of solar cell that includes a perovskite-structured compound, most commonly a hybrid organic–inorganic lead or tin halide-based material as the light-harvesting active layer. Perovskite materials, such a ...

s, which are being evaluated for commercialization. The iodide is the most commonly used. Magneto-optical data storage concepts are also being testing based on various ammonium halides.

Production

These compounds are usually prepared by combining equimolar amounts of

methylamine Methylamine is an organic compound with a formula of . This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine. Methylamine is sold as a solution in methanol, ...

with the appropriate halide acid. For instance methylammonium iodide is prepared by combining methylamine and

hydrogen iodide Hydrogen iodide () is a diatomic molecule and hydrogen halide. Aqueous solutions of HI are known as hydroiodic acid or hydriodic acid, a strong acid. Hydrogen iodide and hydroiodic acid are, however, different in that the former is a gas under sta ...

at 0 °C for 120 minutes followed by evaporation at 60 °C, yielding crystals of methylammonium iodide. :

Crystallography

These compounds' crystallography has been the subject of much investigation. J.S. Hendricks published an early paper on them in 1928. Methylammonium chloride was investigated again in 1946 and methylammonium bromide in 1961.{{Citation, title=The crystal structure of methylammonium bromide, journal=Acta Crystallogr., year=1961, volume=14, issue=12, page=1296, last1=Gabe, first=E.J., doi=10.1107/S0365110X6100382X

References

Halides Methylammonium compounds

Applications

Production

Crystallography

See also

References