Arsenic is a chemical element with the 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 metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry.
A pnictogen is any of the chemical elements in group 15 of the periodic table. Group 15 is also known as the nitrogen group or nitrogen family. It consists of the elements nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and perhaps the chemically uncharacterized synthetic element moscovium (Mc).
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".
Dimercaprol, also called British anti-Lewisite (BAL), is a medication used to treat acute poisoning by arsenic, mercury, gold, and lead. It may also be used for antimony, thallium, or bismuth poisoning, although the evidence for those uses is not very strong. It is given by injection into a muscle.
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.
Stibine (IUPAC name: stibane) is a chemical compound with the formula SbH3. A pnictogen hydride, this colourless gas is the principal covalent hydride of antimony, and a heavy analogue of ammonia. The molecule is pyramidal with H–Sb–H angles of 91.7° and Sb–H distances of 170.7 pm (1.707 Å). This gas has an offensive smell like hydrogen sulfide (rotten eggs).
Arsenic trioxide, sold under the brand name Trisenox among others, is an inorganic compound and medication. As an industrial chemical, whose major uses include in the manufacture of wood preservatives, pesticides, and glass. As a medication, it is used to treat a type of cancer known as acute promyelocytic leukemia. For this use it is given by injection into a vein.
Antimony(III) oxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite. Like most polymeric oxides, Sb2O3 dissolves in aqueous solutions with hydrolysis. A mixed arsenic-antimony oxide occurs in nature as the very rare mineral stibioclaudetite.
Molybdenum hexacarbonyl (also called molybdenum carbonyl) is the chemical compound with the formula Mo(CO)6. This colorless solid, like its chromium and tungsten analogues, is noteworthy as a volatile, air-stable derivative of a metal in its zero oxidation state.
Cacodylic acid is the organoarsenic compound with the formula (CH3)2AsO2H. With the formula R2As(O)OH, it is the simplest of the arsinic acids. It is a colorless solid that is soluble in water.
Scheele's Green, also called Schloss Green, is chemically a cupric hydrogen arsenite, CuHAsO
3. It is chemically related to Paris Green. It is a yellowish-green pigment which in the past was used in some paints, but has since fallen out of use because of its toxicity and the instability of its color in the presence of sulfides and various chemical pollutants. Scheele's Green was invented in 1775 by Carl Wilhelm Scheele. By the end of the 19th century, it had virtually replaced the older green pigments based on copper carbonate.
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."
Potassium arsenite (KAsO2) is an inorganic compound that exists in two forms, potassium meta-arsenite (KAsO2) and potassium ortho-arsenite (K3AsO3). It is composed of arsenite ions (AsO33− or AsO2−) with arsenic always existing in the +3 oxidation state, and potassium existing in the +1 oxidation state. Like many other arsenic containing compounds, potassium arsenite is highly toxic and carcinogenic to humans. Potassium arsenite forms the basis of Fowler’s solution, which was historically used as a medicinal tonic, but due to its toxic nature its use was discontinued. Potassium arsenite is still, however, used as a rodenticide.
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.
Pietro Biginelli was an Italian chemist, who discovered a three-component reaction between urea, acetoacetic ester and aldehydes. He also studied various aspects of sanitation chemistry and chemical products' quality control.
Metalloles are derivatives of cyclopentadiene in which the carbon atom at position 5, the saturated carbon, is replaced by a heteroatom. In contrast to its parent compound, the numbering of the metallole starts at the heteroatom. Some of these compounds are described as organometallic compounds, but in the list below quite a number of metalloids are present too. Many metalloles are fluorescent. Polymeric derivatives of pyrrole and thiophene are of interest in molecular electronics. Metalloles, which can also be viewed as structural analogs of pyrrole, include:
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.
Arsenite methyltransferase is an enzyme with systematic name S-adenosyl-L-methionine:arsenite As-methyltransferase. This enzyme catalyses the following chemical reaction
Bartolomeo Gosio was an Italian medical scientist. He discovered a toxic fume, eponymously named "Gosio gas", which is produced by microorganisms, that killed many people. He identified the chemical nature of the gas as an arsenic compound (arsine), but incorrectly named it as diethylarsine. He also discovered an antibacterial compound called mycophenolic acid from the mould Penicillium brevicompactum. He demonstrated that the novel compound was effective against the deadly anthrax bacterium, Bacillus anthracis. This was the first antibiotic compound isolated in pure and crystallised form. Though the original compound was abandoned in clinical practice due to its adverse effects, its chemical derivative mycophenolate mofetil became the drug of choice as an immunosuppressant in kidney, heart, and liver transplantations.
Cacodyl cyanide is an organoarsenic compound discovered by Robert Bunsen in the 1840s.
