Ligand behaviour and reactivity of phenyl 2-pyridyl ketone azine. Structures of two polymorphic forms of the azine and a copper complex of the 3-phenyltriazolo[1,5-a]pyridine*

Abstract

Two polymorphic forms of phenyl 2-pyridyl ketone azine (L¹) and the complex [ZnL¹Cl₂] have been synthesized and characterized by X-ray diffraction analysis. In the reaction with copper(II) chloride both isomers of the azine undergo hydrolytic and oxidative processes, giving rise to the complex [CuL²₂Cl₂] (L² = 3-phenyltriazolo[1,5-a]pyridine). In order to clarify this process, phenyl 2-pyridyl hydrazone (L³) has been synthesized and treated with copper(II) chloride; in this way CuL²(Cl)·H₂O and CuL³Cl₂ were isolated.