Fully reversible emission color change is achieved by blending a thermoresponsive polymer with dye hybrids. The emission color can be tuned by changing the mixing ratio of each polymer-dye hybrid.

A porphyrin tripod (P Zn T) composed of three zinc porphyrin wings connected via triazole bridges was prepared as a monomeric building block for a supramolecular polymer. P Zn T formed long fibrous supramolecular polymers with a diameter of 7 nm through the axial coordination of triazole nitrogen atoms to zinc porphyrins. The molecular packing structure of a P Zn T-based supramolecular polymer was assigned as a hexagonal columnar phase. P Zn T formed a stable 1:1 host–guest complex with 1,3,5-tris­(4-pyridyl)­benzene (Py 3 B) through axial coordination of pyridyl groups to zinc porphyrins. The host–guest complex between P Zn T and Py 3 B adopts a cone-shaped geometry. After the addition of Py 3 B, the host–guest complex exhibited a characteristic X-ray diffraction pattern of rectangular columnar ordering. Furthermore, the formation of supercoiled helical fibrous assemblies was observed by transmission electron microscopy (TEM).

A porphyrin tripod (DP Zn T) connected through a triazole bridge was prepared as a monomeric building block for guest-induced supramolecular polymerization. Although the lone pair electrons in triazolic nitrogen potentially bind to the zinc porphyrin units through axial ligation, the intrinsic steric hindrance suppressed the coordination of the triazole bridge to the porphyrin unit in DP Zn T. Therefore, DP Zn T formed spherical nanoparticles through π−π interactions. The addition of 1,3,5tri(pyridin-4-yl)benzene (Py 3 B) caused the guest-induced fibrous supramolecular polymerization of DP Zn T by forming a 1:1 host− guest complex, which was further assembled into a fibrous polymer. Furthermore, addition of Cl − to DP Zn T induced the transformation of spherical nanoparticles to networked supramolecular polymers. The fibrous and networked supramolecular polymers of DP Zn T obtained by adding Py 3 B or Cl − were depolymerized to their original spherical particles after adding Cu(ClO 4 ) 2 or AgNO 3 , respectively.

Reversible supramolecular polymerisation and depolymerisation of biomacromolecules are common and fundamental phenomena in biological systems, which can be controlled by the selective modification of biomacromolecules through molecular recognition. Herein, a porphyrin tripod (DPZnT) connected through a triazole bridge was prepared as a monomeric building block for guest-induced supramolecular polymerisation. Although the lone pair electrons in triazolic nitrogen potentially bind to the zinc porphyrin units through axial ligation, the intrinsic steric hindrance suppressed the coordination of the triazole bridge to the porphyrin unit in DPZnT. Therefore, DPZnT formed spherical nanoparticles through π-π interactions. The addition of 1,3,5-tris(pyridine-4-yl)benzene (Py3B) caused the guest-induced fibrous supramolecular polymerisation of DPZnT by forming a 1:1 host-guest complex, which was further assembled into a fibrous polymer. Furthermore, addition of Cl− to DPZnT induced the transformation of spherical nanoparticles to fibrous supramolecular polymers. The fibrous supramolecular polymers of DPZnT obtained by adding Py3B or Cl− were depolymerised to their original spherical particles after adding Cu(ClO4)2 or AgNO3, respectively.