Synthesis and Characterization of Hexaazamacrocyclic Complexes with Co(II), Ni(II), Cu(II), and Zn(II) Derived from Phthalaldehyde and 2,6‐Diaminopyridine

Abstract

A novel family of hexaazamacrocyclic complexes [MLX₂] [M = Co(II), Ni(II), Cu(II), and Zn(II), X = Cl or NO₃] containing pyridine and imine groups as part of the macrocyclic framework have been synthesized by the condensation of o‐phthalaldehyde with 2,6‐diaminopyridine in the presence of metal ions as templates in methanol as solvent. The complexes have been characterized on the basis of elemental analyses, IR, ¹H NMR, EPR, UV‐Visible, magnetic susceptibility, and conductivity measurements at room temperature. An octahedral geometry has been proposed for all of these complexes. The low conductivity data suggest their non‐ionic nature.

Keywords:

• Hexaazamacrocyclic complexes
• Methanol
• Phthalaldehyde
• 2,6‐Diaminopyridine

Acknowledgments

The University Grants Commission, New Delhi, India, is gratefully acknowledged for support of major project No. F‐12‐116/2001. The authors thank the Central Drug Research Institute, Lucknow, India, for providing elemental analyses and ¹H NMR spectra. The Chairman, Department of Chemistry, Aligarh Muslim University, Aligarh, India, is highly acknowledged for providing the other research facilities.