Ever since, diaminomaleonitrile (DAMN) and its derivatives, as intermediates, have been extensively utilized in the synthesis of various type of heterocyclic compounds. In the other hand, unsymmetric DAMN-based Schiff-base ligands and their transition metal complexes have been extensively studied for their interesting physico-chemical properties as well as their potentially catalectic activities. In the present work, new unsymmetric diaminomaleonitrile-based azo-azomethine ligand (H3L) has been synthesized via condensation reaction of 2-amino-3-((5-bromo-2-hydroxybenzyl) amino) maleonitrile with 2-hydroxy-5-((4-nitrophenyl)diazenyl)benzaldehyde in methanol solution. The prepared azo ligand has been characterized by elemental analysis, IR, UV-Vis and 1H NMR spectroscopic methods. Furthermore, the solvatochromic behavior of the ligand was studied by UV-Vis spectroscopy. Also, a new Ni(II) complex was also prepared by reaction of (H3L) and Ni(ClO4)2. 6H2O in CHCl3/ MeOH. The prepared complex was characterized by elemental analysis, IR, UV-Vis spectroscopy. The thermal properties and also antimicrobial activities of the prepared ligand and its corresponding complex were studied.
