1) Copperon 
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: ...
a creamy-white crystalline substance, CHNO, used as a reagent in analytical chemistry for the detection of copper. Also called