Multispectroscopic DNA interaction studies of a water-soluble nickel(II) complex containing different dinitrogen aromatic ligands

• Published in: Transition metal chemistry (Weinheim) 2010-09, Vol.35 (6), p.699-705
• Main Authors: Shahabadi, Nahid, Kashanian, Soheila, Khosravi, Marzieh, Mahdavi, Maryam
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Organometallic Chemistry; Physical Chemistry
• ISSN: 0340-4285; 1572-901X
• DOI: 10.1007/s11243-010-9382-x

The water-soluble Ni(II) complex, [Ni(bipy) 2 (phen-dione)](OAc) 2 ·2H 2 O (bipy = 2,2′-bipyridine and phen-dione = 1,10-phenanthroline-5,6-dione) has been synthesized and characterized by physico-chemical and spectroscopic methods. The binding interactions of this complex with calf thymus DNA (CT-DNA) were investigated using fluorimetry, spectrophotometry, circular dichroism and viscosimetry. In fluorimetric studies, the enthalpy and entropy of the reaction between the complex and CT-DNA showed that the reaction is exothermic (Δ H  = −123.9 kJ mol −1 ; Δ S  = −323.5 J mol −1 K −1 ). The competitive binding studies showed that the complex could not release methylene blue completely. The complex showed absorption hyperchromism in its UV–Vis spectrum with DNA. The calculated binding constant, K b obtained from UV–Vis absorption studies was 2 × 10 5  M −1 . Moreover, the complex induced detectable changes in the CD spectrum of CT-DNA, as well as changes in its viscosity. The results suggest that this nickel(II) complex interact with CT-DNA via a groove-binding mode.