New Metal Chelates of 5-Amino-4-Azopyrazoles: The Crystal and Molecular Structure of Bis{l-phenyl-3-methyl-4-(p-tolyl)azo-5-(p -carboxymethoxyphenyl)pyrazolamidato }copper (II)

摘要

The reactions of 1,3-alkyl(aryl) derivatives of 5-amino-4-azopyrazoles (HL) with copper(2+) acetate afford metal chelates CuL_2. Complexes with the CuN_4 chromophore containing a substituted amino group (X = NR) as a donor, like their azomethine analogues, have a pseudotetrahedral structure. Copper chelates with X = NH are planar. The X-ray diffraction data and an additional hyperfine structure (ahfs) from ~(15)N atoms of the azo group in the labeled complexes provide evidence for the formation of six-membered metallocycles. The coordination polyhedron in bis{ l-phenyl-3-methyl-4-(p-tolyl)azo-5-(p-carboxymethoxyphenyl)pyrazolami-dato}Cu(II) can be described as a pseudotetrahedron.