METAL COMPLEXES OF AZO DYES .I. QUADRIDENTATE COMPLEXES FROM BIDENTATE AZO COMPOUNDS AND ALKANEDIAMINES OR ETHANOLAMINE

o-Halo-o′-hydroxydiarylazo compounds react readily with alkanediamines or ethanolamine in the presence of copper(II) or nickel(II) salts to form in high yield the quadridentate complex of the ligand resulting from nucleophilic displacement of the halogen by the amine. The order of reactivity is I > Br > Cl > F, but even the fluoro compound reacts at room temperature. In polyhaloazo compounds only the ortho halogen is reactive under the reaction conditions. 4-(o-Bromophenylazo)- 3-methyl-1-phenyl-2-pyrazolin-5-one (XI) reacts with ethylenediamine, alone or in the presence of Cu(II), to give the uncomplexed ligand XII, which can be metalized in a separate step with cupric chloride in ethanolamine. The fluoro and bromo compounds Ia and Ic, respectively, also react with ethylenediamine in the absence of metallic salts to form the quadridentate ligand XIV. The o-amino-o′-halo compounds (XVIIIc and XVUId) react with ethylenediamine in a surprising manner to form the reduction product XX. The o-bromotriphenylformazan XXI reacts to form a complex of the four-nitrogen ligand XXII in which the copper is fivecoordinate. The o-(methoxycarbonyl) azo compound XXIII reacts in one step to give the quadridentate complex XXIV. © 1969, American Chemical Society. All rights reserved.