Cacodylic acid

Cacodylic acid
	Ball-and-stick model
Names
	Preferred IUPAC name Dimethylarsinic acid
	Other names Dimethylarsenic acid, Cacodylic acid, Hydroxydimethylarsine oxide, Arsecodile, Ansar, Silvisar, Phytar 560, DMAA, UN 1572
Identifiers
CAS Number	75-60-5 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	1736965
ChEBI	CHEBI:29839 ;
ChEMBL	ChEMBL1231644;
ChemSpider	2418 ;
DrugBank	DB02994 ;
ECHA InfoCard	100.000.804
EC Number	200-883-4;
Gmelin Reference	130562
KEGG	C07308 ;
PubChem CID	2513;
RTECS number	CH7525000;
UNII	AJ2HL7EU8K ;
UN number	1572
CompTox Dashboard (EPA)	DTXSID7020508 ;
	InChI InChI=1S/C2H7AsO2/c1-3(2,4)5/h1-2H3,(H,4,5) Key: OGGXGZAMXPVRFZ-UHFFFAOYSA-N ; InChI=1/C2H7AsO2/c1-3(2,4)5/h1-2H3,(H,4,5) Key: OGGXGZAMXPVRFZ-UHFFFAOYAP;
	SMILES O=[As](O)(C)C;
Properties
Chemical formula	C2H7AsO2
Molar mass	137.9977 g/mol
Appearance	White crystals or powder
Odor	odorless
Density	> 1.1 g/cm3
Melting point	192 to 198 °C (378 to 388 °F; 465 to 471 K)
Boiling point	> 200 °C (392 °F; 473 K)
Solubility in water	66.7 g/100 ml
Solubility	soluble in ethanol, acetic acid ; insoluble in diethyl ether
Acidity (pKa)	6
Magnetic susceptibility (χ)	−79.9·10−6 cm3/mol
Structure
Crystal structure	triclinic, monoclinic
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H331, H410
Precautionary statements	P261, P264, P270, P271, P273, P301+P310, P304+P340, P311, P321, P330, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	4 0 0
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	23-100 mg/kg (rat and mouse, oral)
Safety data sheet (SDS)	External MSDS
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Cacodylic acid is an 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.

Neutralization of cacodylic acid with base gives cacodylate salts, e.g. sodium cacodylate. They are potent herbicides. Cacodylic acid/sodium cacodylate is a buffering agent in the preparation and fixation of biological samples for electron microscopy and in protein crystallography.