A heterotritopic copillar[5]arene monomer by introducing effective neutral guest moieties (methylene chains end‐capped with cyano and triazole groups) to a pillar[5]arene macrocycle is prepared. This well‐designed AB2‐type copillar[5]arene contains strong host–guest recognition motifs that are connected with relatively flexible and long linkers, thus efficiently assembles to form supramolecular hyperbranched polymer (SHP) in chloroform solution, which is characterized by various techniques including 1H NMR, DOSY, viscosity, DLS, and TEM. Particularly, this supramolecular polymer can be effectively depolymerized by adding a competitive butanedinitrile guest.
A biscalix[5]arene–C60 supramolecular structure was utilized for the development of supramolecular fullerene polymers. Di‐ and tritopic hosts were developed to generate the linear and network supramolecular polymers through the complexation of a dumbbell‐shaped fullerene. The molecular association between the hosts and the fullerene were carefully studied by using 1H NMR, UV/Vis absorption, and fluorescence spectroscopy. The formation of the supramolecular fullerene polymers and networks was confirmed by diffusion‐ordered 1H NMR spectroscopy (DOSY) and solution viscometry. Upon concentrating the mixtures of di‐ or tritopic hosts and dumbbell‐shaped fullerene in the range of 1.0–10 mmol L?1, the diffusion coefficients of the complexes decreased, and the solution viscosities increased, suggesting that large polymeric assemblies were formed in solution. Scanning electron microscopy (SEM) was used to image the supramolecular fullerene polymers and networks. Atomic force microscopy (AFM) provided insight into the morphology of the supramolecular polymers. A mixture of the homoditopic host and the fullerene resulted in fibers with a height of (1.4±0.1) nm and a width of (5.0±0.8) nm. Interdigitation of the alkyl side chains provided secondary interchain interactions that facilitated supramolecular organization. The homotritopic host generated the supramolecular networks with the dumbbell‐shaped fullerene. Honeycomb sheet‐like structures with many voids were found. The growth of the supramolecular polymers is evidently governed by the shape, dimension, and directionality of the monomers. 相似文献
Supramolecular polymers have attracted plenty of interest in the scientific community; however, developing controllable methods of supramolecular polymerization remains a serious challenge. This article reviews some recent developments of methods for supramolecular polymerization from controllable fabrication to living polymerization. Three facile methods with general applicability for controllable fabrication of supramolecular polymers have been established recently: the first method is a self‐sorting approach by manipulating ring–chain equilibrium based on noncovalent control over rigidity of monomers; the second is covalent polymerization from supramonomers formed by noncovalent interactions; and the third is supramolecular interfacial polymerization. More excitingly, living supramolecular polymerization has been achieved by two elegant strategies, including seeded supramolecular polymerization under pathway complexity control and chain‐growth supramolecular polymerization by metastable monomers. It is anticipated that this review may provide some guidance for precise fabrication of supramolecular polymers, leading to the construction of supramolecular polymeric materials with controllable architectures and functions. 相似文献
We report supramolecular AB diblock copolymers comprised of well‐defined telechelic building blocks. Helical motifs, formed via reversible addition‐fragmentation chain‐transfer (RAFT) or anionic polymerization, are assembled with coil‐forming and sheet‐featuring blocks obtained via atom‐transfer radical polymerization (ATRP) or ring‐opening metathesis polymerization (ROMP). Interpolymer hydrogen bonding or metal‐coordination achieves dynamic diblock architectures featuring hybrid topologies of coils, helices, and/or π‐stacked sheets that, on a basic level, mimic protein structural motifs in fully synthetic systems. The intrinsic properties of each block (e.g., circular dichroism and fluorescence) remain unaffected in the wake of self‐assembly. This strategy to develop complex synthetic polymer scaffolds from functional building blocks is significant in a field striving to produce architectures reminiscent of biosynthesis, yet fully synthetic in nature. This is the first plug‐and‐play approach to fabricate hybrid π‐sheet/helix, π‐sheet/coil, and helix/coil architectures via directional self‐assembly. 相似文献
Synthesis of novel amphiphilic supramolecular miktoarm star copolymers has been achieved through complementary molecular recognition and interactions between carboxy groups and amino groups. Polystyrenes carrying two and one carboxy groups at the middle of the polymer chain are used as precursors to react with poly(ethylene oxide) (PEO) end‐capped with a primary amine functionality (–NH2) or a quaternary ammonium hydroxide functionality (–N+(CH2CH3)3OH−). The result suggests that the basicity of the amine plays a key role in the molecular recognition procedure. The efficiency of ionic bond formation can be enhanced from 40% up to 97% by using PEO‐N+(CH2CH3)3OH− instead of PEO‐NH2. The obtained supramolecular polymers can be dissociated in dilute acid solution at room temperature.