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Publication Index: PubMedSubject: electrochemistry

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    Article
    Citation - WoS: 76
    Citation - Scopus: 80
    Unique Ligand-Based Oxidative Dna Cleavage by Zinc(ii) Complexes of Hpyramol and Hpyrimol
    (Wiley-v C H verlag Gmbh, 2007) Maheswari, Palanisamy Uma; Barends, Sharief; Oezalp-Yaman, Seniz; de Hoog, Paul; Casellas, Helene; Teat, Simon J.; Reedijk, Jan
    The zinc(II) complexes reported here have been synthesised from the ligand 4-methyl-2-N-(2-pyridylmethyl)aminophenol (Hpyramol) with chloride or acetate counterions. All the five complexes have been structurally characterised, and the crystal structures reveal that the ligand Hpyramol gradually undergoes an oxidative dehydrogenation to form the ligand 4-methyl-2-N-(2-pyridylmethylene)aminophenol (Hpyrimol), upon coordination to Zn-II. All the five complexes cleave the phi X174 phage DNA oxidatively and the complexes with fully dehydrogenated pyrimol ligands were found to be more efficient than the complexes with non-dehydrogenated Hpyramol ligands. The DNA cleavage is suggested to be ligand-based, whereas the pure ligands alone do not cleave DNA. The DNA cleavage is strongly suggested to be oxidative, possibly due to the involvement of a non-diffusible phenoxyl radical mechanism. ne enzymatic religation experiments and DNA cleavage in the presence of different radical scavengers further support the oxidative DNA cleavage by the zinc(II) complexes.
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    Article
    Citation - WoS: 37
    Citation - Scopus: 43
    Synthesis, Spectroscopy and Electrochemical Behaviors of Nickel(ii) Complexes With Tetradentate Shiff Bases Derived From 3,5-bu2t<
    (Pergamon-elsevier Science Ltd, 2005) Kasumov, VT; Özalp-Yaman, S; Tas, E
    Nickel(II) complexes of a series of N,N'-polymethylenebis(3,5-Bu'(2)-salicylaidimine) ligands containing 2,4-di-Bu'(2)-phenol arms, NiLx, were synthesized and their spectroscopic and redox properties were examined. The UV-vis, H-1 NMR spectroscopic and magnetic results indicate that complexes NiL1-NiL4 unlike NiL5 and NiL6 have a square-planar structure in the solid state and in solution. Cyclic voltammograms of NiLx (x= 1-4) complexes displayed two-step oxidation processes. The first oxidation peak potentials of all Ni(II) complexes corresponds to the reversible one-electron oxidation process of the metal center, yielding Ni(III) species. The second oxidation peak of the complexes was assigned as the ligand based oxidation generating a coordinated phenoxyl radical species. (c) 2005 Elsevier B.V. All rights reserved.