Yang et al. (2018) [48] presented the successful fabrication of a new family
of AIE cross-linked supramolecular polymer through hierarchical self-assembly
involving coordination and host–guest interaction. From a newly synthesized
dipyridyl donor G1 containing a TPE scaffold and two nitrile units, a rhomboidal metallacycle G2 with four nitrile units was smoothly obtained. A pillar
[5]arene dimer H was also successfully obtained to play as a linker. Subsequently, driven by the host–guest interaction between rhomboidal metallacycle
G2 and pillar[5]arene dimer H, a new family of AIE cross-linked supramolecular polymer was obtained. Interestingly, such fluorescent supramolecular polymer exhibited dual-stimuli responsive behaviors to halide and competitive
guest. Thus this research enriches the family of supramolecular polymer with
multiple functionalities, which may find potential applications in the fields of
molecular sensors and biological imaging in the future.
16.7 Conclusions
The overview we discussed here is surrounded with the photoresponsive
supramolecular polymer systems constructed via the host–guest interaction,
using hosts including CD, CB, crown ether, calixarene, and pillararene, to
encapsulate the guests in the constructed supramolecular polymer systems.
Furthermore, guest units undergo different reversible structures or conformations under specific light stimulation, resulting in the corresponding changes of
the supramolecular polymer. As far as we can see, photoresponsive supramolecular polymer is one of the hotspots of supramolecular chemistry in recent
years. Since the photoresponsive supramolecular polymer combines the properties of supramolecular polymer, photoisomerization unit, and light absorption
unit, it has extra advantages like long-range responsiveness, low toxicity, and
so on. The changing of specific light not only can achieve the reversible
regulation of supramolecular polymer structure and its assembly morphology
but also will effectively expand its applications in tissue engineering, drug
carrier, and chemical conversion. At the same time, it has important academic
significance to seek simple and effective means to achieve the transformations between supramolecular polymer and covalent polymer [49].
According to the recent published research, the wavelength of most incident
lights are still concentrated in the ultraviolet and visible areas, therefore the
ability to introduce near infrared components into the polymer will greatly
expand its application in biochemistry. Nowadays, self-assembly supramolecular assembled by thermal equilibrium has been progressively approaching the
kinetic-driven system, which has proved more potential value in the development of supramolecular chemistry. In addition, the challenge to be solved is
finding more effective and universal methods to precisely dominate the supramolecular polymers, such as the control of the size and dimension of supramolecular polymer [50].
16 Photoresponsive Supramolecular Polymers Based on Host-Guest Interactions
479
of AIE cross-linked supramolecular polymer through hierarchical self-assembly
involving coordination and host–guest interaction. From a newly synthesized
dipyridyl donor G1 containing a TPE scaffold and two nitrile units, a rhomboidal metallacycle G2 with four nitrile units was smoothly obtained. A pillar
[5]arene dimer H was also successfully obtained to play as a linker. Subsequently, driven by the host–guest interaction between rhomboidal metallacycle
G2 and pillar[5]arene dimer H, a new family of AIE cross-linked supramolecular polymer was obtained. Interestingly, such fluorescent supramolecular polymer exhibited dual-stimuli responsive behaviors to halide and competitive
guest. Thus this research enriches the family of supramolecular polymer with
multiple functionalities, which may find potential applications in the fields of
molecular sensors and biological imaging in the future.
16.7 Conclusions
The overview we discussed here is surrounded with the photoresponsive
supramolecular polymer systems constructed via the host–guest interaction,
using hosts including CD, CB, crown ether, calixarene, and pillararene, to
encapsulate the guests in the constructed supramolecular polymer systems.
Furthermore, guest units undergo different reversible structures or conformations under specific light stimulation, resulting in the corresponding changes of
the supramolecular polymer. As far as we can see, photoresponsive supramolecular polymer is one of the hotspots of supramolecular chemistry in recent
years. Since the photoresponsive supramolecular polymer combines the properties of supramolecular polymer, photoisomerization unit, and light absorption
unit, it has extra advantages like long-range responsiveness, low toxicity, and
so on. The changing of specific light not only can achieve the reversible
regulation of supramolecular polymer structure and its assembly morphology
but also will effectively expand its applications in tissue engineering, drug
carrier, and chemical conversion. At the same time, it has important academic
significance to seek simple and effective means to achieve the transformations between supramolecular polymer and covalent polymer [49].
According to the recent published research, the wavelength of most incident
lights are still concentrated in the ultraviolet and visible areas, therefore the
ability to introduce near infrared components into the polymer will greatly
expand its application in biochemistry. Nowadays, self-assembly supramolecular assembled by thermal equilibrium has been progressively approaching the
kinetic-driven system, which has proved more potential value in the development of supramolecular chemistry. In addition, the challenge to be solved is
finding more effective and universal methods to precisely dominate the supramolecular polymers, such as the control of the size and dimension of supramolecular polymer [50].
16 Photoresponsive Supramolecular Polymers Based on Host-Guest Interactions
479