Synthesis and Physico‐chemical Studies on a 15‐Membered Hexaaza Macrocyclic Ligand Derived from Hydrazine and Its Complexes with Co(II), Ni(II), Cu(II), and Zn(II)

Abstract The macrocyclic ligand, 1,2,6,9,13,14‐hexaaza‐3,5,10,12‐tetramethylcyclopentadecane‐2,5,9,12‐tetraene (L), has been prepared by the condensation reaction of hydrazine, formaldehyde, ethylenediamine, and 2,4‐pentanedione in 2:1:1:2 molar ratio. Metal complexes of the type [MLX2] (M = Co(II), Ni(II), Cu(II), and Zn(II); X = Cl or NO3) have been synthesized by the reaction of L with the corresponding metal salts in methanol. The macrocyclic ligand (L) and its metal complexes have been characterized by elemental analyses, FT‐IR and 1H and 13C NMR spectral studies. The stereochemistry of the metal complexes have been deduced from magnetic moments and band positions in the electronic spectra.