Template‐engineered metal macrocyclic complexes: Synthesis and biological activity.

Three new azamacrocylic complexes of divalent transition‐metal ions were synthesized by taking Co(II), Ni(II), and Cu(II) metal ions as templates. The macrocyclic ligand (12Z,52Z,54E)‐11,12,13,14,15,16,51,52,53,54,55,56‐dodecahydro‐2,4,6,8‐tetraaza‐1 (2,4),5(4,2)‐pyrimidine‐3,7(1,2)‐dibenzenacyclooctaphane‐16,56‐dione was derived from o‐phenylenediamine (OPD) and 2‐thiobarbituric acid (TBA). All the complexes were fully characterized through spectroscopic techniques and elemental analyses. The structures of the macrocyclic complexes were determined by IR, UV–vis, ESI‐MS, TGA, molar conductance, magnetic moment, and electron spin resonance data. On the basis of the above studies, the complexes may be formulated as [MLX2], in which L is a macrocyclic ligand and X = CH3COO−. All the macrocyclic complexes were biologically screened to evaluate their antimicrobial efficacy. DNA binding study of two representative complexes was performed by UV–vis titrations. [ABSTRACT FROM AUTHOR]