Cupferron is jargon for the ammonium salt of the conjugate base derived from ''N''-nitroso-''N''-phenylhydroxylamine. This conjugate base is abbreviated as CU
−. It once was a common reagent for the
complexation
A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or ...
of metal ions, being of interest in the area of
qualitative inorganic analysis
Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds. It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms m ...
. Its formula is NH
4 6H5N(O)NO The anion binds to metal cations through the two oxygen atoms, forming five-membered
chelate
Chelation () is a type of bonding of ions and their molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These l ...
rings.
Synthesis and complexes
Cupferron is prepared from
phenylhydroxylamine and an NO
+ source:
::C
6H
5NHOH + C
4H
9ONO + NH
3 → NH
4 6H5N(O)NO+ C
4H
9OH
Being a bidentate mono-anionic ligand, CU
− forms complexes analogous to those produced with
acetylacetonate. Illustrative complexes include Cu(CU)
2, Fe(CU)
3, and Zr(CU)
4.
References
{{Ammonium salts
Phenyl compounds
Ammonium compounds
Nitroso compounds