homotritopic pillar[5]arene monomer (B 3 ) was synthesized, which comprised of
three symmetrical pillar[5]arene groups linked by rigid alkynyl chains, as well as
the heteroditopic building block (AC), which contained a terpyridyl ligand group and
a triazole binding site. After the addition of metal ions, the hyperbranched polymer
could be constructed by orthogonal self-assembly: pillararene-based host-guest
interaction and metal-ligand bond. By simply altering the metal ions or the percentage of mixed metal ions, different emission colors could be observed. Moreover, the
addition of competitive ligand could result in the quench in the fluorescence emission. This method would provide a convenient approach toward the construction of
structure-tunable fluorescent supramolecular materials with different colors.
Moreover, Cao and coworkers also pioneeringly conducted researches on the
OLED devices based on the AA/BB-type supramolecular polymers constructed by
pillar[5]arene (Fig. 26) [45]. The monomers H3 and G3 were designed based on
fluorene derivatives that lead to a blue emission. Another guest molecule G4 was
synthesized based on fluorene-co-benzothiadiazole derivatives with a green-emitting
character as the dopant unit in the formed linear AA/BB-type supramolecular polymers. As a result of the efficient energy transfer caused by the exciton trapping on
narrow band gap guest G4, by applying a doping strategy, the light-emitting color of
the resulting polymers could be easily turned from blue to green. Meanwhile, photoluminescent efficiencies up to 81.6% were obtained. All the supramolecular polymers
prepared in this work were utilized as the emissive layers (EMLs) in light-emitting
devices, and a maximum luminance efficiency (LE) of nearly 5 cd A
À1 was achieved.
13.3.5 Other Functional Materials
Thermal responsive materials have been widely researched due to their potential
application in controlled drug release, molecular separation, and tissue culture substrates [46]. As well known, their lower critical solution temperature (LCST) was
depended on their external environment. Along with line, Yu and coworkers
constructed a side-chain supramolecular polymer by using the paraquat modified
copolymer and water-soluble pillar[10]arene (WP10) [47]. After the formation of
supramolecular polymer, the T CP was improved by the gradual addition of WP10,
caused by the increased electrostatic repulsion and steric hindrance arising from
the introduction of WP10, which inhibited intraÀ/interpolymer aggregations in
solution more effectively. Moreover, the addition of competitive guest molecule,
1,10-phenanthrolinium, would destroy the supramolecular polymer, resulting in the
recovery of T CP to the original value, reflected by the transparency of the solution.
This method to tune the transparency of solution would be applied as the smart
window [48]. Wang and coworkers synthesized a supramolecular cross-linker polymer network by the host-guest interaction between the glycol-modified pillar[6]
arene (EGP6) and the ferrocene groups [48b]. Due to the thermal responsiveness
of EGP6, the transparency of the hydrogel could be reversibly tuned by the temperature. In the relatively high temperature, the hydrogel became turbid, thus regulating
the input of solar energy for a more comfortable indoor environment. Moreover, by
374
X. Wu et al.
three symmetrical pillar[5]arene groups linked by rigid alkynyl chains, as well as
the heteroditopic building block (AC), which contained a terpyridyl ligand group and
a triazole binding site. After the addition of metal ions, the hyperbranched polymer
could be constructed by orthogonal self-assembly: pillararene-based host-guest
interaction and metal-ligand bond. By simply altering the metal ions or the percentage of mixed metal ions, different emission colors could be observed. Moreover, the
addition of competitive ligand could result in the quench in the fluorescence emission. This method would provide a convenient approach toward the construction of
structure-tunable fluorescent supramolecular materials with different colors.
Moreover, Cao and coworkers also pioneeringly conducted researches on the
OLED devices based on the AA/BB-type supramolecular polymers constructed by
pillar[5]arene (Fig. 26) [45]. The monomers H3 and G3 were designed based on
fluorene derivatives that lead to a blue emission. Another guest molecule G4 was
synthesized based on fluorene-co-benzothiadiazole derivatives with a green-emitting
character as the dopant unit in the formed linear AA/BB-type supramolecular polymers. As a result of the efficient energy transfer caused by the exciton trapping on
narrow band gap guest G4, by applying a doping strategy, the light-emitting color of
the resulting polymers could be easily turned from blue to green. Meanwhile, photoluminescent efficiencies up to 81.6% were obtained. All the supramolecular polymers
prepared in this work were utilized as the emissive layers (EMLs) in light-emitting
devices, and a maximum luminance efficiency (LE) of nearly 5 cd A
À1 was achieved.
13.3.5 Other Functional Materials
Thermal responsive materials have been widely researched due to their potential
application in controlled drug release, molecular separation, and tissue culture substrates [46]. As well known, their lower critical solution temperature (LCST) was
depended on their external environment. Along with line, Yu and coworkers
constructed a side-chain supramolecular polymer by using the paraquat modified
copolymer and water-soluble pillar[10]arene (WP10) [47]. After the formation of
supramolecular polymer, the T CP was improved by the gradual addition of WP10,
caused by the increased electrostatic repulsion and steric hindrance arising from
the introduction of WP10, which inhibited intraÀ/interpolymer aggregations in
solution more effectively. Moreover, the addition of competitive guest molecule,
1,10-phenanthrolinium, would destroy the supramolecular polymer, resulting in the
recovery of T CP to the original value, reflected by the transparency of the solution.
This method to tune the transparency of solution would be applied as the smart
window [48]. Wang and coworkers synthesized a supramolecular cross-linker polymer network by the host-guest interaction between the glycol-modified pillar[6]
arene (EGP6) and the ferrocene groups [48b]. Due to the thermal responsiveness
of EGP6, the transparency of the hydrogel could be reversibly tuned by the temperature. In the relatively high temperature, the hydrogel became turbid, thus regulating
the input of solar energy for a more comfortable indoor environment. Moreover, by
374
X. Wu et al.