Hamacek Josef, Blanc Sylvie, Elhabiri Mourad, Leize Emmanuelle, Van Dorsselaer Alain, Piguet Claude, Albrecht-Gary Anne-Marie
Laboratoire de Physico-Chimie Bioinorganique, UMR 7509 du CNRS, ECPM, Université Louis Pasteur, 25 rue Becquerel, 67200 Strasbourg, France.
J Am Chem Soc. 2003 Feb 12;125(6):1541-50. doi: 10.1021/ja028861q.
We report the self-assembly process of a supramolecular edifice based on the coordination of europium(III) by a ditopic strand L bearing tridentate bis(benzimidazolyl)pyridine subunits. Varying the metal/ligand ratio and using a fruitful combination of electrospray mass spectrometry and absorption spectrophotometry, we characterized three major complexes (EuL(2), Eu(2)L(2), and Eu(2)L(3)) in acetonitrile. Kinetic investigations showed an alternative "braiding" and "keystone" mechanism leading to Eu(2)L(3). The formation mechanism of the dinuclear triple-stranded helicate, which is mainly governed by electrostatic interactions, goes via the "side-by-side" Eu(2)L(2) intermediate. Our thermodynamic and kinetic data allow the prediction of the apparent "magic" self-assembly of Eu(2)L(3) which is fast and efficient only under a strict set of conditions.
我们报道了一种基于双齿链L（带有三齿双（苯并咪唑基）吡啶亚基）与铕（III）配位的超分子结构的自组装过程。通过改变金属/配体比例，并结合电喷雾质谱法和吸收分光光度法，我们对乙腈中的三种主要配合物（EuL(2)、Eu(2)L(2)和Eu(2)L(3)）进行了表征。动力学研究表明，存在一种导致形成Eu(2)L(3)的交替“编织”和“关键”机制。双核三链螺旋体的形成机制主要受静电相互作用支配，通过“并排”的Eu(2)L(2)中间体进行。我们的热力学和动力学数据使得能够预测Eu(2)L(3)明显的“神奇”自组装过程，该过程仅在一组严格条件下才快速且高效。
