Cacodyl oxide

Cacodyl oxide
Names
	Preferred IUPAC name Dimethylarsinous anhydride
	Other names TL-297
Identifiers
CAS Number	503-80-0 ;
3D model (JSmol)	Interactive image;
ChemSpider	10002 ;
ECHA InfoCard	100.376.169
PubChem CID	10431;
CompTox Dashboard (EPA)	DTXSID70198307 ;
	InChI InChI=1S/C4H12As2O/c1-5(2)7-6(3)4/h1-4H3 Key: LOKPKYSOCCPWIZ-UHFFFAOYSA-N ; InChI=1/C4H12As2O/c1-5(2)7-6(3)4/h1-4H3 Key: LOKPKYSOCCPWIZ-UHFFFAOYAL;
	SMILES C[As](C)O[As](C)C;
Properties
Chemical formula	C4H12As2O
Molar mass	255.98 g/mol
	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

Cacodyl oxide is a chemical compound of the formula [(CH₃)₂As]₂O. This organoarsenic compound is primarily of historical significance since it is sometimes considered to be the first organometallic compound synthesized in relatively pure form.

"Cadet's fuming liquid", which is composed of cacodyl and cacodyl oxide, was originally synthesized by heating potassium acetate with arsenic trioxide. It has a disagreeable odor and is toxic.

The molecular structure of [Ph₂As]₂O (Ph = phenyl), the tetraphenyl analogue of cacodyl oxide, has been established by X-ray crystallography.