Search

Solid-state molecular motion is an important feature of a number of compounds, but visualization of these dynamics is challenging. Here, the authors report a molecular diffusion method for visualization and regulation of solid state molecular motion, and application in purity testing.

A plausible hypothesis for the origin of biological homochirality invokes chiral symmetry breaking, transfer, and amplification driven by autocatalysis. Here, the authors experimentally demonstrate that crystallization-driven template autocatalysis induces mirror symmetry breaking and amplification in helices.

2D covalent organic frameworks usually possess a polycrystalline nature as well as lower porosity and surface area than 3D counterparts, limiting their gas storage application. Here, the authors report the formation of single-crystal 2D covalent organic frameworks isomers with atom-resolution structures for methane storage.

Intermolecular singlet fission (xSF) has typically been observed when the interchromophore separation is below ∼5.6 Å because the chromophore coupling is dominated by van der Waals forces. Now, using carbon nanohoop assemblies that allow the chromophore assembly and coupling to be modulated, efficient xSF has been observed at chromophore separations distances up to ∼16 Å.

Cavity-adaptive crystals have useful phototunable properties, but can be challenging to prepare. Here, the authors report the development of such cocrystals by use of a non-macrocyclic host, with elasticity and lasing action.

Nonporous adaptive crystals change their crystalline structures to adaptively transform in response to specific guest molecules. Here, the authors investigate the guest-induced porous gating property of an organic molecule that is used as adsorbent for iodine.

Here authors present “negative pressure” CO₂ adsorption in hydrogen-bonded salts. This behavior, driven by structural phase transitions, enables high-capacity capture (4.2 mmol/g) and regeneration for sustainable carbon management.

Electron transfer in solids is a fundamental process in many functional nanomaterials. Here, the authors directly observe this process via x-ray crystallography for incorporating of electron-donor guest molecules in macrocyclic nanotube crystals.

Organic co-crystals are useful in the fabrication of functional materials, but it is challenging to achieve structural diversity of co-crystals. Here, the authors report nine sets of macrocycle cocrystals with diverse structures and stoichiometric ratios giving different luminescence properties.

Symmetry breaking has potential for the alteration of properties in 2D layered materials, but is challenging to achieve by mechanical stress. Here, the authors report the stress-induced symmetry breaking in a layered molecular crystal, leading to autonomous and fast self-healing under ambient conditions.

Photosalient effects in organic crystals have potential for responsive materials, but design of such materials is challenging. Here, the authors report the development of cocrystals that undergo a solid state transformation on exposure to UV, resulting in photochromism and photosalient behaviour.

The fabrication of organic polymers in single-crystal form is challenging. Here a rare single-crystal porous polymer with solution processability is synthesized by combining a one-dimensional chain structure, dynamic covalent bonds and various intermolecular interactions. This polymer is used as a coating on fabric for ammonia capture.

Effective carbon capture requires rapid gas transport to active sites, challenging to achieve without permanent porosity. Here, the authors report the development of hydrophobic organic crystals that undergo phase transition on exposure to carbon dioxide, allowing efficient carbon capture.

Stereocomplexation is a powerful strategy for improving polymer properties but inefficient complexation remains a major challenge in stereocomplex formation. Here, the authors circumvent the difficulties of conventional stereocomplexation of preformed polymers and, synthesize two enantiopure polymers of opposite chirality simultaneously and in situ as their stereocomplex via topochemical polymerization.

An amino-acid-encoded assembly strategy is developed for the synthesis of programmable chiral Solomon links, featuring tunable cavity dimensions and shapes. This template-free synthetic approach favours homochiral assembly over non-chiral or heterochiral pathways. The resulting interlocked molecules exhibit strong chiral amplification and exceptional enantioselective peptide recognition.

Globally important BTEX hydrocarbons are separated using a T-shaped host with the shape and crystal tiling characteristics of a pentomino. A strategy based on designing and applying crystalline molecular ominos to perform separations of hydrocarbons and other environmentally-relevant compounds is outlined.

Although polymers have been studied for well over a century, there are few examples of covalently linked polymer crystals synthesized directly from solution. Here, the authors demonstrate a strategy to synthesize single crystalline 1D metallo-covalent organic frameworks by combining dynamic covalent chemistry and metal-ligand coordination.

Interpenetration—in which two or more lattices are catenated—is common in metal–organic frameworks (MOFs). Now a deliberate synthesis of hetero-interpenetrated MOFs, with two distinct lattices, has been developed. It can combine the different properties of the two sublattices in one material, as demonstrated with chirality and catalytic activity, delivering an asymmetric catalyst.

Molecular recognition is an important biological process where guest and host molecules interact through non-covalent bonding. Yeet al. show that this can be sensed by the dielectric and ferroelectric signals of the final complexes in a series of metal-coordination compounds with different diol molecules.

The nitrate anion, NO₃⁻, is typically thought of as an electron-donating molecular moiety. Here the authors reveal, however, that when the negative charge on NO₃⁻is smeared out over a large enough area, a positive potential emerges on N that can act as a Lewis acid in the solid state.

Self-assembly is a strategy for making metal-organic materials but controlling the interior of metal-organic crystals remains challenging. Here, the authors report a sequential self-assembly process for synthesizing various interior morphologies of metal-organic crystal demonstrating evolution of form.

The construction of porous solids from discrete organic molecules usually involves the formation of regular porous crystals. In this study, a covalent scrambling reaction gives molecules with a range of shapes that do not pack effectively — manipulation of the reagent ratio allows fine control of porosity.

Crystalline phase transition can be used to detect changes in the solid state properties of materials. Here, the authors describe the mechanical response of a crystal composed of ferrocene-containing rotaxane to laser irradiation.

Helical structures are fundamental in biomolecules like RNA and DNA, yet creating abiotic helices remains a challenge in synthetic chemistry. The authors present hydrogen-bonded organic cocrystals with zig-zag chain, double-, and quadruple helical structures that are related as polymorphs.

Mechanically flexible single crystals are promising materials for advanced technological applications. Here, the authors study the high pressure response of a plastically flexible coordination polymer and provide indication of an overall disparate mechanical response of bulk flexibility and quasi-hydrostatic compression within the same crystal lattice.

In hybrid perovskites, the driving forces of an order–disorder transition that arise from the organic cation and inorganic framework cannot be easily untangled. Here, the authors introduce a cage-in-framework structure in which reorientation of the cage cation does not alter the cubic symmetry of the perovskite lattice.

Single crystal X-ray diffraction is an invaluable tool for molecular structure determination, but growing single crystals is often an arduous process. Here the authors find that the structures of a wide array of molecules can be determined by SCXRD when included in hydrogen-bonded guanidinium organosulfonate host frameworks in a single-step crystallization.

Cryo-STEM tomography of ferritin crystallization is used to reveal nonclassical evolution of crystalline order, indicating that it may be desolvation that drives the continuous evolution of order in crystallization.

Organizing photochromic molecules into 3D networks is a key strategy to access photoresponsive materials, but framework rigidity typically limits conversion efficiency. Here, the authors exploit a flexible metal-organic framework to achieve quantitative and reversible photoisomerization in a porous crystalline solid.

Although DNA nanotechnology has found many applications in developing functional structures, there has never been an independent device contained within a 3D crystal. Now, a self-assembled three-state device that can change the colour of its crystal by diffusion of DNA-ligated dyes has been reported, representing the potential to develop programmable nanomechanical devices.

Mechanical motions of molecular crystals have been limited to in-place movement or slow crawling. Here, the authors describe chiral azobenzene crystals that walk or roll quickly forward in response to heating or cooling, offering new modes of material locomotion.

Highly compressible crystalline materials typically rely on the high compressibility of their chemical bonds. Now, a family of LnFe(CN)₆ frameworks (Ln = Ho, Lu or Y) has been shown to exhibit pronounced volumetric and linear compressibilities through a spring-and-gear mechanism instead, in which a torsionally flexible LnN₆ unit twists reversibly under pressure.

Crystals are typically thought to be brittle and fragile materials, but needles of copper(II) acetylacetonate have now been shown to be flexible enough to be reversibly tied into a knot. Mechanistic investigations using synchrotron X-ray diffraction determined that the elastic bending occurs through rotation of the molecules within the crystal lattice.

Nanoclusters have precise structures and therefore offer a molecular-level approach for studying surface adsorption phenomena. Here, spherical aluminium oxo clusters are synthesized via a co-encapsulation strategy to examine the inclusion of various guest molecules. This model paves the way for rapid recognition of organic molecules by nanoparticle surfaces.

Organic crystal-based materials have potential in optoelectronic materials, but construction of lossless interfaces is challenging. Here, the authors report the growth of organic parallel grouping crystals without grain boundaries, by a solution viscosity-induced binuclear co-growth strategy.

The origin and control of material dynamics are crucial for understanding functional systems, yet direct visualization of rapid changes in single crystals remains challenging. Here, the authors report an anthracene-based molecular crystal platform that enables dual physical control of solid-state [4 + 4] photocycloaddition through temperature and light.

Reversible and unidirectional expansion of an acicular porous molecular crystal is observed with gas uptake. Using in situ structural and photomicrographic techniques, a molecular-level insight is obtained that correlates macroscopic linear expansion of the crystal to the application of gas-specific pressure.

Helical polythiophene and polypyrrole are synthesized using a chiral iron-based metal–organic framework template. Single-handed helices are formed within the framework’s narrow channels, enhancing the chirality-induced spin polarization of the metal–organic framework to 94%.

Using chiroptical imaging, the optical activity of a metal-organic framework (MOF) was directly correlated with its enantiomorphous (mirror-image) crystal shapes, a milestone that was unachievable in Pasteur’s era.

Defect engineering plays a pivotal role in materials science but achieving precise control over defects in pure organic systems remains a challenge. Here, the authors demonstrate the creation of controllable defects in molecular crystals through the supersaturated solution-fed seeded self-assembly of two strategically designed molecules.

Single crystal diffraction is one of the most common and powerful tools for structural elucidation, but obtaining single crystals of adequate size and quality is not always trivial. Here, the authors report a method to crystallize inherently non-crystalline adamantane-like organic-inorganic clusters using π-π interactions between C₆₀ and nano-sized molecules.

Water at interfaces plays crucial roles in various natural phenomena and in material sciences. Here, the authors report the formation of a supramolecular crystal forming a porous framework with anisotropic, information-rich surfaces, accommodating water molecules to form multi-layered water channels.

Designing materials for CO₂ capture under humid conditions is challenging due to the preferential binding of water in most porous adsorbents. Now it has been shown that shape-selective organic macrocycles, identified via bottom-up computational screening, can preferentially bind CO₂ through multiple weak interactions, even in the presence of water.

Surface charging in crystalline materials is a complex phenomenon to predict and design. Here the authors show the origin of surface charges in polar piezoelectric pharmaceuticals to predict the outcome of mechanical impact on their bulk properties.

Spin-active materials with sensitive electron spin centers have drawn significant attention in quantum sensing due to their unique quantum characteristics. Herein, the authors report a molecular spin sensor based on metallofullerene Y₂@C₇₉N for in-situ monitoring of crystallization behavior and phase transitions in aromatic materials with high precision.

The structural transformation of crystals triggered by external stimuli is a fascinating area in materials science and supramolecular chemistry, though it is challenging to maintain crystallinity during an organic reaction. Here the authors show an example of a triethylamine vapor-induced cyclization reaction in a cocrystal, leading to its conversion into polycrystals.

Chiral self-assembled structures have potential in a range of applications, but control of such supramolecular structures is challenging. Here, the authors report a method for the preparation of large area, ordered, chiral supramolecular structures, considering the effects of various factors on the process.

While the shortwave infrared (SWIR) region has potential for bioimaging applications, stable and biocompatible SWIR absorbers/emitters are challenging to access. Here, the authors report the approach of crystal-aided aggregate synthesis for the development of J-aggregates for in vivo bioimaging.

Spontaneous symmetry breaking predominately occurs during the aggregation of discrete molecules in solution. Herein, the authors report a solid-state symmetry breaking process of dynamically chiral aza[4]helicenes that emerges in vacuum-driven transformation of halogen bond-woven crystals.