Scandium complexes hydrazines

The reaction of 2,6-diacetylpyridine with hydrazine in the presence of iron(II) salts yields a macrocyclic azine complex (equation 34).192 Similar complexes of cobalt(II), zinc(II), magnesium ) and scandium(III) have been prepared more recently.193... 

An iron(II) complex of a completely conjugated fourteen-membered hexa-aza ligand has been prepared by the condensation of 2,6-diacetylpyridine with hydrazine in acetonitrile. TTiere are two possible isomers, 134 and 135. X-ray data show that the structure of this complex is best represented by 134 in which the macrocycle is completely planar and the coordination geometry is pentagonal bipyramidal. The iron(II) complex of 134 is extremely labile to nucleophiles 113). The cobalt(II) 113), magnesium(II)114), zinc(II)114), and scandium(III) U5> complexes of this hexa-aza quadradentate ligand have also been prepared. 

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