Max Planck Institute for Polymer Research, Mainz, Germany.
Chemistry. 2013 Apr 26;19(18):5602-8. doi: 10.1002/chem.201204060. Epub 2013 Mar 5.
The ability to pack guest molecules into charged dendronized polymers (denpols) and the possibility to release these guest molecules from subsequently densely aggregated denpols in a load-collapse-release cascade is described. Charged denpols, which constitute molecular objects with a persistent, well-defined envelope and interior, are capable of incorporating large amounts of amphiphilic guest molecules. Simultaneously, multivalent ions can coordinate to the surfaces of charged denpols, leading to counterion-induced aggregation of the already guest-loaded host structures. Thus, although the local guest concentration in denpol-based molecular transport might already be initially high due to the dense guest packing inside the dendritic denpol scaffolding, the "local" guest concentration can nonetheless be further increased by packing (through aggregation) of the host-guest complexes themselves. Subsequent release of guest compounds from densely aggregated dendronized polymers is then possible (e.g., through increasing the solution concentration of imidazolium-based ions). Augmented with this release possibility, the concept of twofold packing of guests, firstly through hosting itself and secondly through aggregation of the hosts, gives rise to a load-collapse-release cascade that strikingly displays the high potential of dendronized macromolecules for future molecular transport applications.
描述了将客体分子包封在荷电树状聚合物(denpols)中以及随后从随后密集聚集的 denpols 中以负载-塌陷-释放级联的方式释放这些客体分子的能力。构成具有持久、明确定义的外壳和内部的分子客体的荷电 denpols 能够容纳大量两亲客体分子。同时,多价离子可以与荷电 denpols 的表面配位,导致已经负载客体的主体结构的抗衡离子诱导聚集。因此,尽管由于树枝状 denpol 支架内的密集客体包封,基于 denpol 的分子传输中的局部客体浓度可能已经初始很高,但通过自身的客体浓度仍可进一步增加(通过聚集)客体 - 主体复合物本身。随后,可以从密集聚集的树状聚合物中释放客体化合物(例如,通过增加基于咪唑鎓的离子的溶液浓度)。通过这种释放可能性的增强,客体的双重包封的概念,首先是通过主体本身,其次是通过主体的聚集,引发了负载-塌陷-释放级联,这显著显示了树状大分子在未来分子传输应用中的巨大潜力。