Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India.
Dalton Trans. 2013 Sep 14;42(34):12495-506. doi: 10.1039/c3dt51095f. Epub 2013 Jul 18.
Crown-ether like interaction of two neutral [Cu2(μ-OH)(μ-L(1))] (H3L(1) = 2-(2'-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) fragments, around a central Na(+) cation as self-assembly template, led to the formation of [Na{Cu2(μ-OH)(μ-L(1))}2]ClO4 (1). Di-tert-butyl group substituted H3L(2) {2-(3,5-di-tert-butyl-2-hydroxyphenyl)-1,3-bis[4-(3,5-di-tert-butyl-2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine} conversely yields only [Cu2(μ-OH)(μ-L(2))]·1.5H2O (2), by discarding aggregation around the Na(+) ion. The crown-ether type aggregate 1 exhibits ferromagnetic interactions within the double oxido-phenoxido [Cu2] fragments and weak antiferromagnetic interactions are mediated by the ONa(+)O bridges. Complex 2 registers only weak antiferromagnetic interactions within the oxido-phenoxido bridged [Cu2] entity. UV-visible and emission titration spectroscopy establish the interaction of cationic complex 1 with calf thymus DNA in Tris buffer and it cleaves supercoiled pBR322 DNA from in situ generated ROS.
两个中性[Cu2(μ-OH)(μ-L(1))]（H3L(1)=2-(2'-羟基苯基)-1,3-双[4-(2-羟基苯基)-3-氮杂丁-3-烯基]-1,3-咪唑烷）片段通过冠醚类似相互作用，围绕中心 Na(+)阳离子作为自组装模板，形成[Na{Cu2(μ-OH)(μ-L(1))}2]ClO4（1）。相反，用叔丁基取代的 H3L(2) {2-(3,5-二叔丁基-2-羟基苯基)-1,3-双[4-(3,5-二叔丁基-2-羟基苯基)-3-氮杂丁-3-烯基]-1,3-咪唑烷}则只能得到[Cu2(μ-OH)(μ-L(2))]·1.5H2O（2），从而摒弃了围绕 Na(+)离子的聚集。冠醚型聚集体 1 在双氧代-苯氧基[Cu2]片段内表现出铁磁相互作用，而弱反铁磁相互作用则由 ONa(+)O 桥介导。配合物 2 在氧代-苯氧基桥联[Cu2]实体内仅记录到弱反铁磁相互作用。紫外-可见和发射滴定光谱表明，在 Tris 缓冲液中，阳离子配合物 1 与小牛胸腺 DNA 相互作用，并从原位生成的 ROS 中切割超螺旋 pBR322 DNA。
