Arsenid

Arsenid, more commonly spelled arsenide in English, refers to chemical species in which arsenic is present in the -3 oxidation state as the arsenide ion As3-, or to compounds containing this ion. In many metal arsenides, arsenic combines with electropositive metals so that the metal is effectively positive while arsenic acts as a monoatomic anion. Arsenides are distinct from arsenites and arsenates, which contain arsenic in positive oxidation states bound to oxygen.

Chemistry and properties tend to vary with composition. The arsenide ion is a strong reducing agent under certain conditions, and many arsenide compounds are crystalline solids with metallic or semiconducting properties. When exposed to acids or certain reactive environments, some arsenides can release arsine (AsH3), a highly toxic and flammable gas, requiring careful handling and ventilation in laboratory and industrial settings.

Occurrence and examples. Arsenides occur both as minerals and as synthetic compounds. Mineral examples include nickel arsenide (NiAs) and iron arsenide (FeAs), which are components of ore deposits. In materials science, important synthetic arsenides include gallium arsenide (GaAs) and indium arsenide (InAs), which are III–V semiconductors widely used in electronics and optoelectronics. Cadmium arsenide (Cd3As2) is studied as a Dirac semimetal in advanced physics research.

Applications and safety. Arsenide materials are central to semiconductor technology, high-speed electronics, and some photonic devices. Due to the toxicity of arsenic and arsine gas, handling requires appropriate protective equipment, engineering controls, and strict compliance with safety regulations.

See also: arsenide minerals, III–V semiconductors, arsine.