Cacodylic acid

Cacodylic acid
Structural formula
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
3D model (JSmol)
1736965
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.804 Edit this at Wikidata
EC Number
  • 200-883-4
130562
KEGG
RTECS number
  • CH7525000
UNII
UN number 1572
  • InChI=1S/C2H7AsO2/c1-3(2,4)5/h1-2H3,(H,4,5) checkY
    Key: OGGXGZAMXPVRFZ-UHFFFAOYSA-N checkY
  • InChI=1/C2H7AsO2/c1-3(2,4)5/h1-2H3,(H,4,5)
    Key: OGGXGZAMXPVRFZ-UHFFFAOYAP
  • O=[As](O)(C)C
Properties
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)
66.7 g/100 ml
Solubility soluble in ethanol, acetic acid
insoluble in diethyl ether
Acidity (pKa) 6
-79.9·10−6 cm3/mol
Structure
triclinic,[3] monoclinic[2]
Hazards
GHS labelling:
GHS06: ToxicGHS09: Environmental hazard
Danger
H301, H331, H410
P261, P264, P270, P271, P273, P301+P310, P304+P340, P311, P321, P330, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
4
0
0
Lethal dose or concentration (LD, LC):
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).
☒N verify (what is checkY☒N ?)

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.

  1. ^ Betz, R.; McCleland, C.; Marchand, H. (2011). "CSD Entry: CADYLA01 : Dimethylarsinic acid". Cambridge Structural Database: Access Structures. Cambridge Crystallographic Data Centre. doi:10.5517/ccx73mv. Retrieved 2021-12-21.
  2. ^ a b Betz, R.; McCleland, C.; Marchand, H. (2011). "The monoclinic polymorph of dimethylarsinic acid". Acta Crystallogr. E. 67 (8): m1013. doi:10.1107/S1600536811025505. PMC 3212109. PMID 22090811.
  3. ^ Trotter, J.; Zobel, T. (1965). "826. Stereochemistry of arsenic. Part XVI. Cacodylic acid". J. Chem. Soc.: 4466–4471. doi:10.1039/JR9650004466.