Supramolecular double-stranded Archimedean spirals and concentric toroids

Abstract

Connecting molecular-level phenomena to larger scales and, ultimately, to sophisticated molecular systems that resemble living systems remains a considerable challenge in supramolecular chemistry. To this end, molecular self-assembly at higher hierarchical levels has to be understood and controlled. Here, we report unusual self-assembled structures formed from a simple porphyrin derivative. Unexpectedly, this formed a one-dimensional (1D) supramolecular polymer that coiled to give an Archimedean spiral. Our analysis of the supramolecular polymerization by using mass-balance models suggested that the Archimedean spiral is formed at high concentrations of the monomer, whereas other aggregation types might form at low concentrations. Gratifyingly, we discovered that our porphyrin-based monomer formed supramolecular concentric toroids at low concentrations. Moreover, a mechanistic insight into the self-assembly process permitted a controlled synthesis of these concentric toroids. This study both illustrates the richness of self-assembled structures at higher levels of hierarchy and demonstrates a topological effect in noncovalent synthesis.

Reversible Micrometer‐Scale Spiral Self‐Assembly in Liquid Crystalline Block Copolymer Film with Controllable Chiral Response

“…In‐depth study of these chiral structures provides opportunities for the design and construction of chiral materials with excellent properties. Various chiral structures, such as helix, [1] spiral, [2] gyroid, [3] toroid, [4] and Moebius strips, [5] have been fabricated based on supramolecular assembly. Among them, the chiral spirals exhibit great sensitivity to external stimulus, just as their natural counterparts.…”

Urea Derivatives as Functional Molecules: Supramolecular Capsules, Supramolecular Polymers, Supramolecular Gels, Artificial Hosts, and Catalysts

“…[44] In recent years, this research has been extended to control of the growth mechanism and the topology. [45][46][47][48][49] Meijer et al reported 2-ureido-4-pyrimidinone, which forms aD DAA/AADD-type (D:h ydrogen bond donor;A :h ydrogen bond acceptor)q uadruple hydrogen bondedd imer,a sahydrogen bonding unit with al arge association constant (K dim > 10 7 m À1 ). [50] Molecule 10,i nw hich two 2-ureido-4-pyrimidinone moieties are covalently linked, forms as upramolecular polymer that shows similar physicalp ropertiest oat ypical polymer formed by covalentb onds (Figure8).…”

“…Since then, research on supramolecular polymers has rapidly developed and expanded into various functional materials [44] . In recent years, this research has been extended to control of the growth mechanism and the topology [45–49] …”

Synthesis methods of organic two‐dimensional materials

“…Masayuki Takeuchi and Kazunori Sugiyasu et al demonstrated that molecular self-assembly under kinetic control achieved metastable nanostructures that were otherwise thermodynamically inaccessible and the length/area/shape of supramolecular nanosheets were controllable. [60][61][62] Self-assembly could be described by 2D seeded supramolecular polymerization or nucleationelongation models (Figure 4(A)). 61 Suhrit Ghosh et al also reported photo-triggered supramolecular polymerization and they found that photo-initiated supramolecular assembly had an in-built growth mechanism which differed from the spontaneous self-assembly (Figure 4(B)).…”

“…Recently, kinetically controlled/living supramolecular polymerization from an identical monomer is expected to yield 2D nanostructures. Masayuki Takeuchi and Kazunori Sugiyasu et al demonstrated that molecular self‐assembly under kinetic control achieved metastable nanostructures that were otherwise thermodynamically inaccessible and the length/area/shape of supramolecular nanosheets were controllable 60–62 . Self‐assembly could be described by 2D seeded supramolecular polymerization or nucleation–elongation models (Figure 4(A)).…”