A 1-D alternating copper(II) chain based on three acetate-bridging modes: synthesis, crystal structure, DNA binding and magnetic properties

<p>A new 1-D alternating copper(II) polymer, [Cu<sub>2</sub>(L)(OAc)<sub>4</sub>]<sub>n</sub> (<b>1</b>) (L = 5-chloro-2-(pyridine-2-yl)benzo[<i>d</i>]thiazole), has been isolated and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, and magnetic susceptibility. The complex crystallized in the triclinic space group P-1, <i>a</i> = 8.2277(16) Å, <i>b</i> = 9.4233(19) Å, <i>c</i> = 15.831(3) Å, <i>α</i> = 103.38(3)°, <i>β</i> = 99.95(3)°, <i>γ</i> = 92.70(3)°, <i>V</i> = 1171.3(4) Å<sup>3</sup>, and comprises a 1-D polymer linked by three kinds of acetate-bridging modes in an alternating manner. UV–visible and fluorescence spectra revealed that <b>1</b> is bound to CT-DNA in a partial intercalation mode. Through gel electrophoresis assays, <b>1</b> displayed an efficient oxidative cleavage activity on supercoiled plasmid DNA (pUC19) in the presence of H<sub>2</sub>O<sub>2</sub>. Magnetic measurements were performed from 2 to 300 K, and the experimental results were satisfactorily reproduced with <i>J</i><sub>1</sub> = –160 ± 20 cm<sup>−1</sup>, <i>J</i><sub>2</sub> = 5.8 ± 0.2 cm<sup>−1</sup>, <i>zJ′</i> = 0.381 ± 0.005 cm<sup>−1</sup> and <i>g</i> = 2.1, showing antiferromagnetic coupling between Cu1 and Cu1i, ferromagnetic exchange between Cu2 and Cu2ii, and a weak ferromagnetic molecular field correction accounting for all interspecies interactions.</p>