Synthesis and structure of chelates of aryl- and acylhydrazones of aromatic aldehydes with transition-metal ions

1. A number of complexes of aryl- and acylhydrazones of benzaldehyde and salicylaldehyde have been synthesized. The composition and structure of these complexes have been established on the basis of the IR spectra and the data from elemental analysis. 2. In the case of the formation of the complexes with hydrazones, divalent copper, unlike the other metal ions studied, is capable of being reduced by the ligand. 3. Theα-hydroxyazone structure of the copper and nickel complexes of benzaldehyde benzoylhydrazone and the copper complexes of the salicylaldehyde acylhydrazones has been established. Here the enol hydrogen of theα-hydroxyazine structure is replaced by the metal, while in the complexes of the salicylaldehyde acylhydrazones with cadmium, manganese, iron, cobalt, and nickel the chelatization takes place with replacement of the phenol hydrogen.