Supramolecular polymers

Chemical fuel-driven supramolecular systems have been developed showing out of-equilibrium functions such as transient gelation and oscillations but these systems suffer from undesired waste accumulation and they function only in open systems. Here, the authors we report non-equilibrium supramolecular polymerizations in a closed system, which is built by viologens and pyranine in the presence of hydrazine hydrate.

Crowding effects have long been established as powerful guiding forces in natural assembly processes. Here the authors report a bioinspired approach translating this phenomenon to artificial supramolecular polymers.

Preassembled materials are ubiquitous in our everyday life due to their readiness and functionality; an end-user simply follows instructions to assemble them and harness function. Here, metastable rotaxanes are utilized to approach preassembled materials: a multicomponent, preprogrammed system can be conveniently (via heating) transformed into colorful polymer networks at the end-user’s will.

Controlling multicomponent systems is difficult due to convoluted behavior, pathway complexity, and coupled equilibria. Here the authors showed modulation of aggregate morphology in a zinc porphyrin-based supramolecular system via judicious capping with a manganese porphyrin monomer, in which the monomer’s chirality can influence the supramolecular behavior.

Living supramolecular polymerization can produce precise covalent polymers, but the scope of monomers is still narrow. Here the authors show a molecular platform for living supramolecular polymerization that is based on the unique structure of all-cis 1,2,3,4,5,6- 22 hexafluorocyclohexane, the most polar aliphatic compound reported to date.

Using simple monomers in living supramolecular polymerization is difficult due to energy principles. Here the authors use confinement from a layered double hydroxide nanomaterial to successfully polymerise several simple monomers with length control and narrow dispersity.

Defects and disordered local domains in soft, self-assembled aggregates determine their dynamic and adaptive properties, and enable communication between entities, but characterizing and classifying such intricate dynamic behaviors is highly complex. Here, the authors report on a data-driven workflow to identify objective criteria for the comparison of complex dynamic features in soft supramolecular materials, deriving a data-driven ’defectometer’ that allows to classify soft self-assembled materials based on the structural dynamics of the ordered/disordered molecular environments that statistically emerge within them.

The dynamic structure of supramolecular polymers is challenging to determine both in experiments and in simulations. Here the authors use coarse-grained molecular models to provide a comprehensive analysis of the molecular communication in these complex molecular systems.

Reversible assembly of supramolecular polymers renders these materials with healing and recycling properties but mechanical properties are often inferior to those of conventional plastics. Here, the authors demonstrate that strong and tough but healable materials can be accessed through the combination of metallosupramolecular polymers with complementary mechanical properties that feature the same metal-ligand complex as binding motif

The mechanics of reconfigurable supramolecular polymer networks are governed by their dynamic crosslinking chemistry and the resulting stress relaxations. Here, the authors use reversible wrinkling patterns to visualize localized stress relaxations, due to molecular network rearrangements.

Strategies to construct circularly polarized luminescence (CPL)-active materials with color modulation and handedness of CPL are desirable for the synthesis of chiral photo-responsive devices. Here the authors develop a CPL system based on styrylpyrenes. Benefiting from CH-π interactions between chromophores, the styrylpyrene aggregates show color-dependent CPL property and photo-responsive behavior.

Metallo-supramolecular polymers have demonstrated promise for applications in displays, sensors, and storage devices, but control over their synthesis remains a challenge. Here, the authors report on the stepwise introduction of three different transition metals into a metallo-supramolecular polymer and highlight its potential as an electrochromic display material.

Sequential energy transfer is ubiquitous in natural light harvesting systems, but most artificial mimics have unsatisfactory energy transfer efficiency. Here, authors synthesize a sequential energy transfer system with overall efficiency of 87.4% via supramolecular copolymerization mimicking the aggregation mode of bacteriochlorophyll pigments in green photosynthetic bacteria.

Eco-friendly, efficient, and selective gold recovery technologies are urgently desired to satisfy the increasing demand for gold. Here, the authors report one such technology based on the supramolecular polymerization of second-sphere coordinated adducts formed between β-cyclodextrin and tetrabromoaurate anions.

Spontaneous liquid–liquid phase-separation behaviour of high-aspect-ratio fibrils, obtained from supramolecular polymerizations of synthetic components, forms tactoids by means of an entropy-driven pathway.

Supramolecular structures are typically formed by the one-step self-assembly of building blocks. Now, a greater level of control has been achieved using stepwise non-covalent reactions under kinetic control. Two-dimensional block supramolecular polymers with tailored compositions and sequences were synthesized, and a site selectivity that is reminiscent of regioselectivity in covalent synthesis was observed.

Glass-like supramolecular polymer networks with high compressibility and fast self-recovery are fabricated using host–guest crosslinkers with slow dissociation kinetics.

The solvent-free conversion of phthalonitrile derivatives into phthalocyanines in the bulk is described, involving a reductive cyclotetramerization step and the formation of one-dimensional single-crystalline fibres. This solvent-free autocatalytic supramolecular polymerization may enable for a sustainable fabrication of multi-block supramolecular copolymers.

Peptide amphiphile supramolecular polymers with a crosslinked spiropyran network respond to light by expelling water, enabling the fabrication of soft actuators or light-driven crawlers.

Beginning with a historical retrospective, this Review highlights the progress from thermodynamically and kinetically controlled self-assembly processes towards seed-induced living supramolecular polymerization, which allows the formation of highly ordered, functional materials such as supramolecular block copolymers.