Department of Chemistry, Aligarh Muslim University, Aligarh-202002, India.
Chem Biodivers. 2009 Dec;6(12):2275-89. doi: 10.1002/cbdv.200800282.
New bis-macrocyclic complexes of Co(III), 1, Ni(II), 2, and Cu(II), 3, containing pyridyl bridges between 13-membered macrocyclic subunits, have been synthesized via an in situ one-pot template condensation reaction (IOPTCR). The proposed structures of these new dinuclear complexes are consistent with the data obtained from elemental analysis, molar conductance, IR, EPR, UV/VIS, (1)H- and 13C-NMR, and ESI-MS. The complexes 2 and 3 possess square-planar geometry with four secondary N-atoms coordinated to the metal ion, while complex 1 reveals octahedral geometry in solution due to coordinated H(2)O molecules. DNA-Binding properties of the complexes 1 and 3 were investigated by absorption and emission titrations, cyclic voltammetry, and viscosity measurements. Complexes 1 and 3 are strong DNA binders with binding constants, K(b), of 1.64 x 10(5) and 2.05 x 10(5) M(-1), respectively. Hyperchromism, decrease in emission intensity of DNA-bound ethidium bromide (EB), and changes observed in the viscosity and cyclic voltammograms in the presence of added metal complexes reveals that the complexes bind to DNA predominantly by electrostatic attraction, substantiated by absorption titration with 5'-GMP.
新的 Co(III)、1、Ni(II)、2 和 Cu(II)、3 的双大环配合物通过原位一锅模板缩合反应 (IOPTCR) 合成，其中吡啶桥连接 13 元大环亚基。这些新双核配合物的结构与元素分析、摩尔电导率、IR、EPR、UV/VIS、(1)H 和 13C-NMR 以及 ESI-MS 获得的数据一致。配合物 2 和 3 具有平面正方形几何形状，四个次级 N 原子与金属离子配位，而配合物 1 由于配位的 H(2)O 分子在溶液中呈现八面体几何形状。通过吸收和发射滴定、循环伏安法和粘度测量研究了配合物 1 和 3 的 DNA 结合性质。配合物 1 和 3 是强 DNA 结合剂，结合常数 K(b)分别为 1.64 x 10(5) 和 2.05 x 10(5) M(-1)。增色效应、结合 DNA 的溴化乙锭 (EB) 的发射强度降低以及存在外加金属配合物时观察到的粘度和循环伏安图的变化表明，配合物主要通过静电吸引与 DNA 结合，这得到了与 5'-GMP 的吸收滴定的证实。
