:Cadet's fuming liquid
{{Short description|Mixture of organoarsenic compounds}}
File:Cacodyl-oxide-3D-balls.png
Cadet's fuming liquid was a red-brown oily liquid prepared in 1760 by the French chemist Louis Claude Cadet de Gassicourt (1731-1799) by the reaction of potassium acetate with arsenic trioxide.{{cite journal | title = Cadet's Fuming Arsenical Liquid and the Cacodyl Compounds of Bunsen | first = D. | last = Seyferth | journal = Organometallics | year = 2001 | volume = 20 | issue = 8 | pages = 1488–1498 | doi = 10.1021/om0101947 | doi-access = free }} It consisted mostly of dicacodyl (((CH3)2As)2) and cacodyl oxide (((CH3)2As)2O).
The global reaction (mass balance) corresponding to the oxide formation is the following:
: {{chem2|4 CH3COOK + As2O3 → ((CH3)2As)2O + 2 K2CO3 + 2 CO2}}
These were the first organometallic substances prepared; as such, Cadet has been regarded as the father of organometallic chemistry.{{ cite book | author = Jaouen, G. | title = Bioorganometallics: Biomolecules, Labeling, Medicine | publisher = Wiley | year = 2006 | isbn = 3-527-30990-X }}
This liquid develops white fumes when exposed to air, resulting in a pale flame producing carbon dioxide, water, and arsenic trioxide. It has a nauseating and very disagreeable garlic-like odor.
Around 1840, Robert Bunsen did much work on characterizing the compounds in the liquid and its derivatives. His research was important in the development of radical theory.