摘要
通过合理分子设计,合成了分别含有柱芳烃主体基元和氰基客体基元且具有不同尺寸的吡啶给体D1和D2,同时选择120?双铂金属盐A作为受体,从三组分出发,通过"一锅法"配位键导向自组装,自分类得到分别含有3个柱[5]芳烃单元的金属有机大环H和含有3个氰基中性客体的金属有机大环G.随着体系浓度增大,通过柱芳烃共价大环与中性氰基客体之间主客相互作用,逐级自组装形成以2种分立金属有机大环为交联点的新型超分子聚合物.所得到的超分子聚合物通过变浓度核磁氢谱(1H-NMR)、动态光散射(DLS)、二维核磁扩散序谱(DOSY)、扫描电镜(SEM)等进行了表征.有趣的是,进一步增加浓度(9.9 wt%),超分子聚合物转化成超分子聚合物凝胶,并且在温度、中性有机小分子及卤素离子等多重刺激下实现凝胶-溶液的可逆转化.
A dipyridyl donor D1 decorated with pillar[5]arene unit and a dipyridyl donor D2 containing neutral guest moiety were successfully synthesized. Through the X-ray single crystal analysis, it was found that the angle between the two pyridine unit in D1 was about 128° and the distance between two nitrogen atoms was about 1.48 nm, while the angle between the two pyridine units of D2 was about 118° and the distance between the two nitrogen atoms was about 0.98 nm, much shorter than that in D1. Thus, a metallacycle containing three pillar[5]arene units （H） and a metallacycle possessing three neutral guest units （G） were successfully constructed in one pot coordination-driven self-assembly from dipyridyl donors （DI and D2） and 120~ di-Pt（II） acceptor through size-control self-sorting strategy. Moreover, driven by the host-guest interaction between metallacycles H and G, a new family of supramolecular polymer, cross-linked by these two kinds of discrete well-defined metllacycles H and G, was gradually constructed with the increase of concentration. By concentration-dependent IH-NMR measurement, it was found that the typical signals of metllacycle G were gradually disappeared with the increase of concentration, indicating the enhanced host-guest interaction between metallacycles I-I and G. Meanwhile, the analysis of 2-D diffusion ordered spectroscopy （DOSY） tests of HDG showed that the diffusion coefficient D gradually decreased with the increase of concentration, and D1 mmol/L/Dl6 rnmol/L value was ca. 31.6, also demonstrating the formation of supramolecular polymer. Scanning electron microscope （SEM） was also used to investigate the morphology change during the concentration increasing process. More intuitionally, cross-linked networks were observed with the increase of concentration of HDG. Interestingly, the resultant supramolecular polymer could transforme into supramolecular polymer gels when the concentration was increased to a relatively high value （9.9 wt%）. Moreover, due to the existence of discrete well-defined metallacycles and the dynamic nature of host-guest hierarchical self-assembly, reversible gel-sol transitions were successfully realized through the disassembly and reassembly of such cross-linked supramolecular polymer networks stimulated by various external stimuli such as temperature, competitive guest, and halide, etc.
作者
张昌伟
欧波
尹光强
陈丽君
杨海波
Chang-wei Zhang Bo Ou Guang-qiang Yin Li-jun Chen Hai-bo Yang(Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, Shanghai 200062)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2017年第1期71-79,共9页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号21322206和21132005)资助项目
关键词
超分子聚合物
凝胶
配位键导向自组装
主客体作用
自分类
Supramolecular polymer gel, Coordination-driven self-assembly, Host-guest interaction, Self-sorting
