Macrocyclic dinuclear nickel(II) and manganese(II) complexes: synthesis, X-ray crystal structures, DNA cleavage, and antimicrobial activity studies

Abstract

Three dinuclear macrocyclic complexes, [Ni2L1(μ-OAc)(H2O)(CH3O)](ClO4)2·4(H2O) (1), [Mn2L2(μ-OAc) (H2O)]ClO4·H2O (2) and [Mn2L3(μ-OAc)]ClO4·H2O (3), (where H2L1, H2L2 and H2L3 are the [2 + 2] condensation products of 2,6-diformyl-4-fluorophenol with diethylenetriamine and N,N-bis(3-aminopropyl)-2-thiopheno-ethylamine, respectively), have been synthesized and characterized. The electrochemical characteristics showed that the metal centers are more electropositive when strongly electron-withdrawing groups are attached to the macrocyclic ring, and hence more easily reduced. All three complexes have been found to promote cleavage of plasmid pBR322 DNA from the supercoiled form I to the open circular form II. The antibacterial activities of the complexes were also studied.