Studies on Metal Chelate Compounds of Phenazine Derivatives. VIII. Metal Complexes of 1-Hydroxyphenazine

Abstract

Acid dissociation constant (pK_a) of 1-hydroxyphenazine and stability constants of its metal complexes with bivalent metals such as Cu, Ni, Co, Zn, and Cd were determined by spectrophotometry in 50% (v/v) ethanol. It was found that pK_a of 1-hydroxyphenazine was 9.21 and stability constants of these complexes were similar to those of 5-hydroxyquinoxaline-metal complexes, being smaller than those of 8-hydroxyquinoline-metal complexes. The binding ratio of 1-hydroxyphenazine-metal complexes was 2 : 1 from elemental analyses and mass spectrum. In its mass spectrum, the fragmentation of these 2 : 1 metal complexes was in good agreement with those of 8-hydroxyquinoline-metal complexes.