Arsenic trifluoride, commonly called arsenic(III) fluoride and written AsF3, is an inorganic halide of arsenic. It is a molecular compound in which arsenic is in the +3 oxidation state and is bonded to three fluorine atoms. AsF3 is most often encountered as a colorless, volatile liquid with a penetrating odor and is handled only in controlled laboratory or industrial settings. Basic data on the compound cover its formula, nomenclature, and classification among arsenic halides.
Structure and chemical characteristics
The molecule adopts a trigonal pyramidal arrangement driven by a lone pair on arsenic, giving it C3v-like symmetry. The As–F bonds are polar covalent, and the compound is discrete (nonpolymeric) under normal conditions. Because of the strong affinity of fluorine for hydrogen and oxygen, arsenic trifluoride reacts with water to give hydrolysis products and acidic fluoride species, so it must be kept dry. For more on atomic properties and bonding, see structural references.
Preparation and uses
AsF3 can be prepared by halogen-exchange routes or direct fluorination methods in specialized inorganic chemistry contexts. It appears in research laboratories as a reagent for fluorine-transfer reactions and as a precursor in the synthesis of other arsenic fluorides and coordination complexes. Its role is largely niche: it is not a common industrial feedstock but is valuable in studies of arsenic coordination chemistry and in selected synthetic transformations. Practical notes and synthetic methods are discussed in technical resources here.
Safety, handling, and environmental notes
Arsenic trifluoride is highly toxic and corrosive. Inhalation, ingestion, or skin contact can cause severe poisoning; it also liberates hydrogen fluoride on contact with water, which adds corrosive and systemic hazards. Work with AsF3 requires appropriate ventilation, personal protective equipment, and procedures for containment and neutralization. Dispose of wastes according to hazardous-material regulations and institutional protocols. Safety guidance and emergency measures are summarized in safety documents available here.
Compared with related compounds such as arsenic trichloride and antimony trifluoride, AsF3 stands out for the strong electronegativity of fluorine, which influences its reactivity and hydrolysis behavior. For further reading and data compilations consult specialized chemical handbooks and databases linked resources.