Phenylarsonic acid is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the

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 ...

C₆H₅AsO(OH)₂, commonly abbreviated PhAsO₃H₂. This colourless solid is an organic derivative of

arsenic acid Arsenic acid or trihydrogen arsenate is the chemical compound with the formula . More descriptively written as , this colorless acid is the arsenic analogue of phosphoric acid. Arsenate and phosphate salts behave very similarly. Arsenic acid as ...

, AsO(OH)₃, where one OH group has been replaced by a

phenyl In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula C6 H5, and is often represented by the symbol Ph. Phenyl group is closely related to benzene and can be viewed as a benzene ring, minus a hydrogen ...

group. The compound is a

buffering agent A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is a ...

and a precursor to other

organoarsenic compound 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 fungic ...

s, some of which are used in animal nutrition, e.g.

4-hydroxy-3-nitrobenzenearsonic acid Roxarsone is an organoarsenic compound that has been used in poultry production as a feed additive to increase weight gain and improve feed efficiency, and as a coccidiostat. As of June 2011, it was approved for chicken feed in the United States, ...

Preparation and structure

PhAsO₃H₂ can be prepared in several routes, but a common one entails treatment of phenyl

diazonium Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halide. General properti ...

salts with sodium

arsenite In chemistry, an arsenite is a chemical compound containing an arsenic oxyanion where arsenic has oxidation state +3. Note that in fields that commonly deal with groundwater chemistry, arsenite is used generically to identify soluble AsIII anions. ...

(prepared from arsenious acid and base) in the presence of a copper(II)

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

. : + NaAsO₃H₂ → C₆H₅AsO₃H₂ + Na⁺ + N₂ Related derivatives are prepared similarly. It was first prepared by Michaelis and Loenser. X-ray crystallography indicates that the molecules are connected by hydrogen-bonds consistent with short distance of 2.5 Å separating the

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

atoms. The arsenic center is tetrahedral.Struchkov, Yu. T. "Crystal and molecular structure of phenylarsonic acid" Russian Chemical Bulletin 1960, Volume 9, 1829-1833. {{doi, 10.1007/BF00907739

Related phenylarsonic acids

Several derivatives of phenylarsonic acid have been used as additives for animal feeds. These include

(3-NHPAA, or Roxarsone), ''p''-arsanilic acid (''p''-ASA), 4-nitrophenylarsonic acid (4-NPAA), and ''p''-ureidophenylarsonic acid (''p''-UPAA).

References

Phenyl compounds Arsonic acids