Dimethylarsinic acid

Structural formula
General
Surname	Dimethylarsinic acid
other names	Cacodylic acid Agent Blue
Molecular formula	C 2 H 7 AsO 2
Brief description	colorless, hygroscopic crystals
External identifiers / databases
CAS number 75-60-5 EC number 200-883-4 ECHA InfoCard 100,000,804 PubChem 2513 ChemSpider 2418 DrugBank DB02994 Wikidata Q420680
properties
Molar mass	138.00 g mol −1
Physical state	firmly
Melting point	195-196 ° C
solubility	very light in water (2000 g l −1 ) practically insoluble in diethyl ether , soluble in glacial acetic acid , readily soluble in ethanol
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 301-331-410 P: 261-273-301 + 310-311-501
Toxicological data	644 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Dimethylarsinic acid , also called cacodylic acid, is an organometallic compound of arsenic . It belongs to the class of arsenic acids .

properties

Dimethylarsinic acid is a flammable, white, hygroscopic solid that dissolves very well in water. The aqueous solution is acidic. The dimethylarsinic acid has an unpleasant odor.

use

Dimethylarsinic acid is used to wash electron microscope slides. Sodium cacodylate, the sodium salt of cacodylic acid, is used in protein crystallization as a buffer with a pH range of 5.0-7.4.

Dimethylarsinic acid is also used as a non-selective herbicide for weed control on non-cultivated land, for defoliation and drying up of cotton crops before harvest and for killing unwanted trees by means of injection. However, it is not approved as a crop protection agent in the European Union or Switzerland . During the Vietnam War , dimethylarsinic acid and its sodium salt were used under the name Agent Blue to destroy rice crops.

Biological importance

Dimethylarsinic acid is formed in the metabolism of mammals as a breakdown product of more toxic arsenic (V) and arsenic (III) compounds and is excreted in the urine.

safety instructions

Like most arsenic compounds, dimethylarsinic acid is toxic.

Individual evidence

1. ↑ ^{a b c d} Entry on dimethylarsinic acid. In: Römpp Online . Georg Thieme Verlag, accessed on May 1, 2014.
2. ↑ ^{a b c} Entry on dimethylarsinic acid in the GESTIS substance database of the IFA , accessed on February 10, 2017(JavaScript required) .
3. ↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry arsenic compounds, with the exception of those named in this appendix in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA) on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
4. ^ Entry on dimethylarsinic acid in the ChemIDplus database of the United States National Library of Medicine (NLM) .
5. ↑ Wolfgang Legrum: Fragrances, between stink and fragrance , Vieweg + Teubner Verlag (2011) pp. 72–73, ISBN 978-3-8348-1245-2 .
6. ^ Directorate-General for Health and Food Safety of the European Commission: EU pesticide database ; Entry in the national directory of plant protection products in Switzerland ; Retrieved June 20, 2016.
7. ↑ R. Braun (Ed.): Special toxicology for chemists: A selection of toxic substances , BG Teubner Verlag, 1999, pp. 72–73, ISBN 3-519-03538-3 .