By the reaction of 1-Fluoro-2-nitrobenzene with homopiperazine, the new polyamine 2,2′-(1,4 -diazepane -1,4-diyl)dianiline (A) was prepared. The N4O2 Schiff base ligands were synthesized from condensation of polyamine A with 2-hydroxybenzaldehyde (H2L1) or 2‑hydroxy-3-methoxybenzaldehyde (H2L2). Four macroacyclic Schiff-base complexes were obtained by reaction of cobalt (II) and copper (II) ions with ligands. All resulting compounds were characterized by 13C and 1H NMR, FT-IR, elemental analysis and mass spectrometry. Molar conductivity (ɅM) data were determined using 10−3 molar solutions of the synthesized compounds in acetonitrile. The antioxidant activity of all products has been studied. The geometries of the [MLn]m+ (M = Co, Cu; Ln = L1, L2, L3, L4; m = 0, 1) complexes containing homopiperazine or piperazine moiety were optimized at the BP86/def2-SVP level of theory. Furthermore with the help of NBO and EDA, the nature of M ← Ln (n = 1 − 4) bonds in complexes are studied.
