Highly Controllable Ring–Chain Equilibrium in Quadruply Hydrogen Bonded Supramolecular Polymers
作者:Tangxin Xiao、Xiaoqing Feng、Shuyang Ye、Yangfan Guan、Shao-Lu Li、Qi Wang、Ya Ji、Dunru Zhu、Xiaoyu Hu、Chen Lin、Yi Pan、Leyong Wang
DOI:10.1021/ma302459n
日期:2012.12.21
synthesized, which could form small cyclic monomers, oligomers, or linear supramolecular polymers at certain concentration in solution, to achieve a highly controllable ring–chain equilibrium self-assembling supramolecular system. The ring–chain equilibrium of these supramolecular monomers constructed by different lengths of oligo(ethylene oxide) (oligoEO) chain as spacers were investigated by a combination
合成了富电子双氧萘(DNP)桥联的双功能脲基嘧啶酮(UPy)衍生物(L1,L2和L3),它们可以在溶液中以一定浓度形成小的环状单体,低聚物或线性超分子聚合物,以实现高度可控环链平衡自组装超分子系统。这些超分子单体的环链构成平衡通过寡聚的不同长度(环氧乙烷)(oligoEO)链作为间隔物通过的技术的组合研究,例如11 H NMR,DOSY,单晶X射线衍射和粘度测定法。实验结果表明,DNP基团与这些超分子单体的单体环状形式的分子内二聚化UPy基序之间存在分子内π-π堆积相互作用,而这种π-π堆积相互作用的强度直接取决于寡聚EO链的长度。此外,发现强大的分子内π-π堆积相互作用可促进有利于分子内环状单体化的自组装,从而导致临界聚合浓度(CPC)大大提高。单体L1a具有最短oligoEO链长度的化合物作为分子内氢键结合的唯一类型(即环状单体)存在于溶液中的宽浓度范围(1.6–500 mM)中。彻底