Chemistry of polydentate ligands. Part 3. Ring closures effected by the reaction of β-diketones with 6,6′-dihydrazino- and 6,6′-di(N-methylhydrazino)-2,2′-bipyridylnickel(II) diperchlorate

Abstract

Pentane-2,4-dione (Hpd) and benzoylacetone both react with 6,6′-dihydrazino-2,2′-bipyridylnickel(II) diperchlorate in a manner which leads to ring closure about each hydrazine moiety forming substituted derivatives of pyrazole. In contrast, the reaction of Hpd with 6,6′-di(N-methylhydrazino)-2,2′-bipyridyl in the presence of Ni^II leads to the formation of a complex containing a thirteen-membered macrocycle.