акодиловая кислота

Химические свойства

white crystals or powder

Использование

Cacodylic acid is used for dermatologic treatment in cronic eczema, anemia and as a tonic.

Определение

ChEBI: The organoarsenic compound that is arsenic acid substituted on the central arsenic atom with two methyl groups.

Общее описание

A colorless, odorless crystalline solid. Melting point 195-196°C. Toxic by ingestion and irritating to skin and eyes.

Реакции воздуха и воды

Hygroscopic. Water soluble.

Профиль реактивности

CACODYLIC ACID is a weak acid. Dissolves in water to yield solutions containing more hydrogen ions than pure water contains and so having a pH less than 7.0. Is neutralized exothermically by all bases to produce water plus a salt. Reacts (but usually slowly) with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for the solid acid but are quite slow if the solid acid remains dry. The solid may absorb enough water from the air and dissolve sufficiently in CACODYLIC ACID to corrode or dissolve iron, steel, and aluminum parts and containers. Reacts with cyanide salts to generate gaseous hydrogen cyanide. Flammable and/or toxic gases and heat may be generated with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Also may react with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still some heat. Can be oxidized exothermically by strong oxidizing agents and reduced by strong reducing agents; a wide variety of products is possible. May initiate polymerization reactions; may catalyze (increase the rate of) chemical reactions.

Опасность

Toxic by ingestion.

Угроза здоровью

Chemical is essentially non-irritating in contact with skin or eyes. Ingestion causes arsenic poisoning, but symptoms are delayed.

Пожароопасность

Behavior in Fire: May form toxic oxides of arsenic when heated.

Перевозки

UN1572 Cacodylic acid & UN1688 Sodium Cacodylate, Hazard Class: 6.1; Labels: 6.1-Poisonous materials. UN3465 Organoarsenic compound, solid, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required

Методы очистки

Recrystallise it from warm EtOH (3mL/g) by cooling and filtering. Dry it in a vacuum desiccator over CaCl2. It has also been recrystallised twice from propan-2-ol. [Koller & Hawkridge J Am Chem Soc 107 7412 1985, Beilstein 4 IV 3681.]

Несовместимости

A strong reducing agent. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Aqueous solution reacts violently with chemically active metals releasing toxic arsenic fumes. Incompatible with oxidizers, sulfuric acid; caustics (strong bases), reducing agents; ammonia, amines, isocyanates, alkylene oxides; epichlorohydrin.