Alajarín Mateo, Pastor Aurelia, Orenes Raúl-Angel, Steed Jonathan W, Arakawa Ryuichi
Departamento de Química Orgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo, Murcia-30.100, Spain.
Chemistry. 2004 Mar 19;10(6):1383-97. doi: 10.1002/chem.200305559.
A set of tris(2-ureidobenzyl)amines 3 was prepared and their dimerization processes thoroughly investigated. In spite of their inherent flexibility, tris(ureas) 3 form dimeric aggregates both in the solid state and in solution. Evidence for the existence of these dimeric species was provided by a combination of techniques (X-ray analysis, NMR and IR spectroscopy, and ESI-MS). The association constants and thermodynamic parameters for the dimerization processes of selected tris(ureas) were determined and show that they are enthalpically driven. Heterodimerization experiments in solution reveal a high degree of self-recognition or narcissistic self-sorting. On the other hand, desymmetrized tris(ureas) derived from 3 self-assemble with modest regioselectivities depending on the terminal substituent of every urea functionality.
制备了一组三（2-脲基苄基）胺3，并对其二聚过程进行了深入研究。尽管它们具有固有的灵活性，但三脲3在固态和溶液中均形成二聚聚集体。通过多种技术（X射线分析、核磁共振和红外光谱以及电喷雾质谱）相结合，提供了这些二聚体存在的证据。测定了所选三脲二聚过程的缔合常数和热力学参数，结果表明它们是由焓驱动的。溶液中的异二聚化实验显示出高度的自我识别或自恋式自分类。另一方面，由3衍生的去对称化三脲根据每个脲官能团的末端取代基以适度的区域选择性进行自组装。
