Arsenic is a chemical element; it has symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a notoriously toxic metalloid. It has various allotropes, but only the grey form, which has a metallic appearance, is important to industry.
Arsine (IUPAC name: arsane) is an inorganic compound with the formula AsH3. This flammable, pyrophoric, and highly toxic pnictogen hydride gas is one of the simplest compounds of arsenic. Despite its lethality, it finds some applications in the semiconductor industry and for the synthesis of organoarsenic compounds. The term arsine is commonly used to describe a class of organoarsenic compounds of the formula AsH3−xRx, where R = aryl or alkyl. For example, As(C6H5)3, called triphenylarsine, is referred to as "an arsine".
A blood agent is a toxic chemical agent that affects the body by being absorbed into the blood. Blood agents are fast-acting, potentially lethal poisons that typically manifest at room temperature as volatile colorless gases with a faint odor. They are either cyanide- or arsenic-based.
Cacodyl, also known as dicacodyl or tetramethyldiarsine, (CH3)2As–As(CH3)2, is an organoarsenic compound that constitutes a major part of "Cadet's fuming liquid" (named after the French chemist Louis Claude Cadet de Gassicourt). It is a poisonous oily liquid with an extremely unpleasant garlicky odor. Cacodyl undergoes spontaneous combustion in dry air.
Agent Blue is one of the "rainbow herbicides" that is known for its use by the United States during the Vietnam War. It contained a mixture of dimethylarsinic acid and its related salt, sodium cacodylate, and water.
Arsenic trioxide is an inorganic compound with the formula As
2O
3. As an industrial chemical, its major uses include the manufacture of wood preservatives, pesticides, and glass. It is sold under the brand name Trisenox among others when used as a medication to treat a type of cancer known as acute promyelocytic leukemia. For this use it is given by injection into a vein.
Cacodyl oxide is a chemical compound of the formula [(CH3)2As]2O. This organoarsenic compound is primarily of historical significance since it is sometimes considered to be the first organometallic compound synthesized in relatively pure form.
Diphenylchloroarsine (DA) is the organoarsenic compound with the formula (C6H5)2AsCl. It is highly toxic and was once used in chemical warfare. It is also an intermediate in the preparation of other organoarsenic compounds. The molecule consists of a pyramidal As(III) center attached to two phenyl rings and one chloride. It was also known as sneezing oil during World War I by the Allies.
Arsenic tribromide is an inorganic compound with the formula AsBr3, it is a bromide of arsenic. Arsenic is a chemical element that has the symbol As and atomic number 33. This pyramidal molecule is the only known binary arsenic bromide. AsBr3 is noteworthy for its very high refractive index of approximately 2.3. It also has a very high diamagnetic susceptibility. The compound exists as colourless deliquescent crystals that fume in moist air.
1,2-Bis(dimethylarsino)benzene (diars) is the organoarsenic compound with the formula C6H4(As(CH3)2)2. The molecule consists of two dimethylarsino groups attached to adjacent carbon centers of a benzene ring. It is a chelating ligand in coordination chemistry. This colourless oil is commonly abbreviated "diars."
Organoarsenic chemistry is the chemistry of compounds containing a chemical bond between arsenic and carbon. A few organoarsenic compounds, also called "organoarsenicals," are produced industrially with uses as insecticides, herbicides, and fungicides. In general these applications are declining in step with growing concerns about their impact on the environment and human health. The parent compounds are arsane and arsenic acid. Despite their toxicity, organoarsenic biomolecules are well known.
Cadet's fuming liquid was a red-brown oily liquid prepared in 1760 by the French chemist Louis Claude Cadet de Gassicourt (1731-1799) by the reaction of potassium acetate with arsenic trioxide. It consisted mostly of dicacodyl (((CH3)2As)2) and cacodyl oxide (((CH3)2As)2O).
Methyldichloroarsine, sometimes abbreviated "MD" and also known as methyl Dick, is an organoarsenic compound with the formula CH3AsCl2. This colourless volatile liquid is a highly toxic vesicant that has been used in chemical warfare.
Disodium methyl arsenate (DSMA) is the organoarsenic compound with the formula CH3AsO3Na2. It is a colorless, water-soluble solid derived from methanearsonic acid. It is used as a herbicide. Tradenames include Metharsinat, Arrhenal, Disomear, Metharsan, Stenosine, Tonarsan, Tonarsin, Arsinyl, Arsynal, and Diarsen.
Arsenic biochemistry refers to biochemical processes that can use arsenic or its compounds, such as arsenate. Arsenic is a moderately abundant element in Earth's crust, and although many arsenic compounds are often considered highly toxic to most life, a wide variety of organoarsenic compounds are produced biologically and various organic and inorganic arsenic compounds are metabolized by numerous organisms. This pattern is general for other related elements, including selenium, which can exhibit both beneficial and deleterious effects. Arsenic biochemistry has become topical since many toxic arsenic compounds are found in some aquifers, potentially affecting many millions of people via biochemical processes.
Radical theory is an obsolete scientific theory in chemistry describing the structure of organic compounds. The theory was pioneered by Justus von Liebig, Friedrich Wöhler and Auguste Laurent around 1830 and is not related to the modern understanding of free radicals. In this theory, organic compounds were thought to exist as combinations of radicals that could be exchanged in chemical reactions just as chemical elements could be interchanged in inorganic compounds.
Arsinic acids are organoarsenic compounds with the formula R2AsO2H. They are formally, but not actually, related to arsinic acid, a hypothetical compound of the formula H2AsO2H. Arsinic acids are monoprotic, weak acids. They react with sodium sulfide to give the dithioarinates R2AsS2Na. Arsinic acids are related to phosphinic acids (R2PO2H.).
Cacodyl cyanide is a highly toxic organoarsenic compound discovered by Robert Bunsen in the 1840s. It is very volatile and flammable, as it shares the chemical properties of both arsenic and cyanide.
An arsinide, arsanide, dihydridoarsenate(1−) or arsanyl compound is a chemical derivative of arsine, where one hydrogen atom is replaced with a metal or cation. The arsinide ion has formula AsH−2. It can be considered as a ligand with name arsenido or arsanido. Researchers are unenthusiastic about studying arsanyl compounds, because of the toxic chemicals, and their instability. The IUPAC names are arsanide and dihydridoarsenate(1−). For the ligand the name is arsanido. The neutral −AsH2 group is termed arsanyl.
Compounds of arsenic resemble in some respects those of phosphorus which occupies the same group (column) of the periodic table. The most common oxidation states for arsenic are: −3 in the arsenides, which are alloy-like intermetallic compounds, +3 in the arsenites, and +5 in the arsenates and most organoarsenic compounds. Arsenic also bonds readily to itself as seen in the square As3−
4 ions in the mineral skutterudite. In the +3 oxidation state, arsenic is typically pyramidal owing to the influence of the lone pair of electrons.
