Syntheses of Metallic Monoazo Complexes

Some ortho-hydroxy monoazo-compounds have been synthesized and these were metallized with transition elements. Chromium trioxide, cupric acetate and cobalt acetate were used for the metallization. The following facts have been found in this investigation: (1) water is the best solvent, when compared to various organic solvents, for the metallization, (2) the optimum pH for the metallizing mixture ranges from 4.5 to 5.5, (3) the solubility of these metallic monoazo-compounds in water depends mainly on the composition of the complexes and to some extent on the presence of sulfonic acid groups in the molecules, and (4) metallized compounds having two ortho-hydroxy groups per molecule have stronger binding characteristics.