Syntheses, Structures and Properties of Two Unsymmetrical Bis-Furan Pendant-Armed Macrocyclic Dinuclear Cu(II) Complexes

Two unsymmetrical macrocyclic dinuclear copper complexes [Cu-2(L-1)Cl-2]center dot CH3CN (1) and [Cu-2(L-2)Br-2]center dot CH3CN center dot H2O (2) [H2L was derived from the condensation between 1,6-bis (2-furyl)- 2,5-bis(5-X-2-hydroxy-3-formylbenzyl)-2,5-diazahexane (X =Cl or Br)and 1,3-diaminopropane] have been synthesized and fully characterized. The interactions of these complexes with calf thymus-DNA were studied by UV-Vis, viscosity experiment, CD spectroscopic and agarose gel electrophoresis. Absorption spectroscopic investigation reveals that 1 and 2 can intercalate into CT-DNA, with binding constants of 6.2x10(5) and 7.2x10(5), respectively. The appearance of increased CD bands near 246 and 278 nm gives evidence for effective complexes DNA binding. The viscosity studies indicate that the binding mode of the complexes belong to an unclassical intercalative mode. The agarose gel electrophoresis studies show that the complexes display effective DNA cleavage activity in the absence of any external agents via oxidative mechanism. CCDC: 963138, 1; 963139, 2.