Physico-analytical studies on some heterocyclic azo dyes and their metal complexes with some transition metals.

In this investigation, the azo dyes; 2-(3'-phenyl-5'-pyrazolyl azo) schaffer acid (la) and 2-(3'-phenyl-5'-pyrazolyl azo) resorcinol (Ib); were prepared through diazotizing 3-phenyl-5-aminopyrazole (PAP) and coupling the resulting diazonium salt with Schäffer acid and resorcinol respectively. The prepared azo dyes are characterized using both IR spectra and the elemental analysis (C, H, N and S). The prepared azo dyes are used as chromogenic reagents for the spectrophotometric determination of copper (II), nickel (II), cobalt (II) and zinc (II) ions.