Title: Cupferron
CAS Registry Number: 135-20-6
CAS Name: N-Hydroxy-N-nitrosobenzenamine ammonium salt
Additional Names: N-nitrosophenylhydroxylamine ammonium salt
Molecular Formula: C6H9N3O2
Molecular Weight: 155.15
Percent Composition: C 46.45%, H 5.85%, N 27.08%, O 20.62%
Literature References: Prepd from phenylhydroxylamine by treating with NaNO2 at 0° in presence of HCl, filtering, dissolving in ether and treating with NH3, or by treating an ether soln of phenylhydroxylamine with butyl or amyl nitrite and NH3 in the cold: Marvel, Kamm, Org. Synth. 4, 19 (1925).
Properties: Crystals, mp 163-164°. Freely sol in water or alc. Keep in well-closed containers to which a piece of ammonium carbonate has been added.
Melting point: mp 163-164°
CAUTION: This substance is reasonably anticipated to be a human carcinogen: Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-73.
Use: As a reagent for separating Sn from Zn, and Cu and Fe from other metals. Ppts iron quantitatively from strongly acid soln; as a quantitative reagent for vanadates with which it gives a dark-red ppt sol in alkali soln, and for Ti with which it forms a yellow ppt; also suitable for the colorimetric estimation of Al.
Cupreine Cupric Acetate Cupric Acetoarsenite Cupric Arsenite Cupric Bisglycinate

CAS number 135-20-6
PubChem 2724103
ChemSpider 2006262 YesY
Jmol-3D images Image 1
Molecular formula C6H9N3O2
Molar mass 155.15 g/mol
Melting point 150–155 °C
Solubility in water soluble
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Cupferron, the ammonium salt of N-nitroso-N-phenylhydroxylamine, is a common reagent for the complexation of metal ions. Its formula is NH4[C6H5N(O)NO]. The anion binds to metal cations through the two oxygen atoms, forming five-membered chelate rings.

Cupferron is prepared from phenylhydroxylamine and an NO+ source:

C6H5NHOH + C4H9ONO + NH3 → NH4[C6H5N(O)NO] + C4H9OH