One-pot template synthesis and properties of Ni(II) complexes of 16-membered hexaaza macrocycles

Abstract

A new nickel(II) complex of the 16-membered hexaaza macrocyclic ligand “1,3,7,9,11,15-hexaazacyclohexadecane, (L 1); 1,9-dimethyl-, (L 2); 1,9-diethyl-, (L 3); 1,9-dibutyl iso -, (L 4); 1,9-dibutyl sec -, (L 5) and 1,9-dibenzyl-1,3,7,9,11,15-hexaazacyclohexadecane (L 6)” have been prepared by the one-pot template reactions of formaldehyde and propylenediamine (pn) with alkyl and benzyl amine in the presence of nickel(II) ion. The complexes of a hexaaza macrocycle have been characterized by elemental analyses, IR, UV–Vis and 13C NMR spectroscopy, conductometric and magnetic measurements. The complexes of nickel(II) have square-planar coordination geometry in the solid state and in nitromethane. The spectra of [NiL 1–6](ClO 4) 2 shows that the four secondary nitrogen atoms are coordinated to the nickel(II) ion. Synthesis, characterization and solution behavior of the nickel(II) complexes of hexaaza macrocycle are reported.