Single-Step Solution-Phase Synthesis of Free-Standing Two-Dimensional Polymers and Their Evolution into Hollow Spheres

Nitrogen-Rich Triptycene-Based Porous Polymer for Gas Storage and Iodine Enrichment

A new kind of nitrogen-rich triptycene-based porous polymer (NTP) with high surface area of up to 1067 m² g^-1 was synthesized by a modified Yamamoto-type Ullmann cross-coupling reaction. Having structure features of expanded conjugated area and nitrogen atoms doping in polymer networks, the NTP displays extraordinary gas storage ability and excellent iodine adsorption capability.

Supramolecular organic frameworks: engineering periodicity in water through host-guest chemistry

The development of homogeneous, water-soluble periodic self-assembled structures comprise repeating units that produce porosity in two-dimensional (2D) or three-dimensional (3D) spaces has become a topic of growing interest in the field of supramolecular chemistry. Such novel self-assembled entities, known as supramolecular organic frameworks (SOFs), are the result of programmed host-guest interactions, which allows for the thermodynamically controlled generation of monolayer sheets or a diamondoid architecture with regular internal cavities or pores under mild conditions. This feature article aims at propagating the conceptually novel SOFs as a new entry into conventional supramolecular polymers. In the first section, we will describe the background of porous solid frameworks and supramolecular polymers. We then introduce the self-assembling behaviour of several multitopic flexible molecules, which is closely related to the design of periodic SOFs from rigid multitopic building blocks. This is followed by a brief discussion of cucurbit[8]uril (CB[8])-encapsulation-enhanced aromatic stacking in water. The three-component host-guest pattern based on this stacking motif has been utilized to drive the formation of most of the new SOFs. In the following two sections, we will highlight the main advances in the construction of 2D and 3D SOFs and the related functional aspects. Finally, we will offer our opinions on future directions for both structures and functions. We hope that this article will trigger the interest of researchers in the field of chemistry, physics, biology and materials science, which should help accelerate the applications of this new family of soft self-assembled organic frameworks.

Self-Exfoliated Guanidinium-Based Ionic Covalent Organic Nanosheets (iCONs)

Covalent organic nanosheets (CONs) have emerged as functional two-dimensional materials for versatile applications. Although π-π stacking between layers, hydrolytic instability, possible restacking prevents their exfoliation on to few thin layered CONs from crystalline porous polymers. We anticipated rational designing of a structure by intrinsic ionic linker could be the solution to produce self-exfoliated CONs without external stimuli. In an attempt to address this issue, we have synthesized three self-exfoliated guanidinium halide based ionic covalent organic nanosheets (iCONs) with antimicrobial property. Self-exfoliation phenomenon has been supported by molecular dynamics (MD) simulation as well. Intrinsic ionic guanidinium unit plays the pivotal role for both self-exfoliation and antibacterial property against both Gram-positive and Gram-negative bacteria. Using such iCONs, we have devised a mixed matrix membrane which could be useful for antimicrobial coatings with plausible medical benefits.

The construction of a two-dimensional supramolecular organic framework with parallelogram pores and stepwise fluorescence enhancement

A novel single-layer two-dimensional (2D) supramolecular organic framework (SOF) with parallelogram pores has been assembled to turn on the fluorescence emission of a non-emissive building block, and the emission could be further enhanced by the aggregation of the as-prepared 2D monolayers.

pH-Responsive single-layer honeycomb supramolecular organic frameworks that exhibit antimicrobial activity

2D single-layer supramolecular organic frameworks have been constructed, which exhibit antimicrobial activity and pH-responsivity.

MasterChem: cooking 2D-polymers

This review summarized the current state-of-the-art in the field of synthetic 2D-polymers showing different routes to prepare these polymers and their physical properties.

Two-dimensional polymers: concepts and perspectives

The emerging class of 2D polymers is explored from physicochemical, synthetic, and analytical viewpoints. Prospects for their properties are provided.

Free-Standing Monolayer Two-Dimensional Supramolecular Organic Framework with Good Internal Order

Utilizing dynamic self-assembly and self-sorting to obtain large-area, molecularly precise monolayered structures represents a promising approach toward two-dimensional supramolecular organic frameworks (2D SOF) or 2D supramolecular polymers. So far, related approaches suffer from small domain sizes, fragility and weak long-range internal order. Here we report on the self-assembly of a host-guest enhanced donor-acceptor interaction, consisting of a tris(methoxynaphthyl)-substituted truxene spacer, and a naphthalene diimide substituted with N-methyl viologenyl moieties as donor and acceptor monomers, respectively, in combination with cucurbit[8]uril as host monomer toward monolayers of an unprecedented 2D SOF. Featuring orthogonal solubility, the participating molecules self-assemble at a liquid-liquid interface, yielding exceptionally large-area, insoluble films, which were analyzed by transmission electron microscopy, atomic force microscopy and optical microscopy to be monolayers with a thickness of 1.8 nm, homogeneously covering areas up to 0.25 cm(2), and featuring the ability to be free-standing over holes of 10 μm(2). Characterization with ultraviolet-visible absorption spectroscopy, solid-state nuclear magnetic resonance spectroscopy, infrared spectroscopy, and grazing incidence wide-angle X-ray scattering allowed for confirmation of a successful complexation of all three monomers toward an internal long-range order and gave indications to an expected hexagonal superstructure. Our results extend the existing variety of two-dimensional soft nanomaterials by a versatile supramolecular approach, whereas the possibility of varying the functional monomers is supposed to open adaptability to different applications like membranes, sensors, molecular sieves, and optoelectronics.

The Organic Flatland-Recent Advances in Synthetic 2D Organic Layers

Ultrathin, 2D organic layers of sub-ten nanometer thicknesses and high aspect ratios have received a great deal of attention for their graphene-like topological features and emerging properties. Rational synthetic strategies have led to the realization of periodic 2D layers with unprecedented structural precision. Herein, recent progress on the synthesis of 2D organic layers, including methods based on both non-covalent and covalent interactions, is summarized, and potential applications are highlighted. Such 2D organic nanostructures have a brilliant future as prospective multifunctional materials, showing great promise as platforms for engineering novel optoelectronic, interfacial, and bioactive properties.

Fabrication of SERS-active conjugated copolymers/gold nanoparticles composite films by interface-directed assembly

A new composite film was synthesised by taking advantage of interface-directed assembly between thiol group-functionalized copolymers and Au NPs. The film not only exhibited strongly Au NP concentration-dependent SERS activity, but also allowed detection of a model molecule.

The construction of single-layer two-dimensional supramolecular organic frameworks in water through the self-assembly of rigid vertexes and flexible edges

Single-layer two-dimensional supramolecular organic frameworks were constructed through self-assembly of rigid vertexes, flexible edges, and cucurbit[8]uril hosts.

Highly thermally stable hydrogels derived from monolayered two-dimensional supramolecular polymers

Hydrogels have been constructed from monolayered two-dimensional (2D) supramolecular polymers in water. The as-prepared hydrogels exhibited extremely high thermal stabilities, which demonstrates how the 2D structure can impact the bulk properties of soft materials.

Hierarchical supramolecules and organization using boronic acid building blocks

Current progress on hierarchical supramolecules using boronic acids has been highlighted in this feature article. The feasibility of the structure-directing ability is fully discussed from the standpoint of the generation of new smart materials.

Graphene-like single-layered covalent organic frameworks: synthesis strategies and application prospects

Two-dimensional (2D) nanomaterials, such as graphene and transition metal chalcogenides, show many interesting dimension-related materials properties. Inspired by the development of 2D inorganic nanomaterials, single-layered covalent organic frameworks (sCOFs), featuring atom-thick sheets and crystalline extended organic structures with covalently bonded building blocks, have attracted great attention in recent years. With their unique graphene-like topological structure and the merit of structural diversity, sCOFs promise to possess novel and designable properties. However, the synthesis of sCOFs with well-defined structures remains a great challenge. Herein, the recent development of the bottom-up synthesis methods of 2D sCOFs, such as thermodynamic equilibrium control methods, growth-kinetics control methods, and surface-assisted covalent polymerization methods, are reviewed. Finally, some of the critical properties and application prospects of these materials are outlined.

A two-dimensional single-layer supramolecular organic framework that is driven by viologen radical cation dimerization and further promoted by cucurbit[8]uril

Without or with the assistance of CB[8], a triangular radical monomer can self-assemble into 2D supramolecular organic frameworks in water.

Rational design and synthesis of covalent organic polymers with hollow structure and excellent antibacterial efficacy

A covalent organic polymer with hollow structure (COP-H) has been synthesizedviaSonogashira coupling from the precursors containing positive charge.

Triptycene based organosoluble polyamides: synthesis, characterization and study of the effect of chain flexibility on morphology

Triptycene based thermally stable, organosoluble and low viscous polyamides have been prepared. Polymers may be categorized as self-extinguishing materials. Relation between structural flexibility and surface morphology has been studied.

An enzyme-responsive supra-amphiphile constructed by pillar[5]arene/acetylcholine molecular recognition

A novel molecular recognition motif between a water-soluble pillar[5]arene (WP5) and acetylcholine is established with an association constant of (5.05 ± 0.13) × 10⁴ M⁻¹.