Abstract The front cover artwork is provided by Anne‐Déborah Nguindjel and Peter A. Korevaar, Radboud University. The image represents the concept of self‐sustained Marangoni flows. These flows bring the fuel to the reaction center, to keep the flow “alive” in its out‐of‐equilibrium state.. Read the full text of the Article at 10.1002/syst.202100021 .

Abstract The design of biomimetic systems in the laboratory is a long‐sought goal for systems chemists and synthetic biologists alike. Fundamental to this design is the generation of self‐assembled structures capable of mimicking compartmentalisation, which includes the encapsulation of molecular cargo as well as the display of molecules on the exterior. Protein nanocompartments are fast becoming popular scaffolds for these systems due to their robust self‐assembly, ability to encapsulate non‐native cargo, and amenability to surface modifications. In this Review, we discuss the primary methods for displaying a wide array of molecular motifs on compartment surfaces. We discuss benefits and drawbacks of each type of display and examine three recent case studies wherein molecular display was a critical design element in the construction of multi‐enzyme chemical systems. The analyses and case studies presented in this Review aim to provide a critical summary of the technologies currently used for molecular display to add another dimension to the design of chemical systems and nanoreactors.

Abstract Fuel‐regulated self‐assembly is a key principle by which Nature creates spatiotemporally controlled materials and dynamic molecular systems that are in continuous communication (molecular exchange) with the external environment. Designing artificial materials that self‐assemble and disassemble via conversion/consumption of a chemical fuel is a grand challenge in supramolecular chemistry, which requires a profound knowledge of the factors governing these complex systems. Here we focus on recently reported metal‐coordinated monomers that polymerise in the presence of ATP and depolymerise upon ATP hydrolysis, exploring their fuel‐regulated self‐assembly/disassembly via multiscale molecular modelling. We use all‐atom simulations to assess the role of ATP in stabilising these monomers in assemblies, and we then build on a minimalistic model to investigate their fuel‐driven polymerisation and depolymerisation on a higher scale. In this way, we elucidate general aspects of fuel‐regulated self‐assembly that are important toward the rational design of new types of bioinspired materials.

Abstract The front cover artwork is provided by our research group at Emory University, Atlanta (USA). The image depicts the diverse array of single β‐sheets that we have identified spectroscopically existing within metastable solute‐rich peptide phases. As the particle phase grows in time, sheet‐sheet stacking appears to nucleate fibril assembly. Read the full text of the Communication at 10.1002/syst.202000007 .

Abstract The front cover artwork is provided by the Thiele group at Leibniz IPF Dresden (Germany). The image shows a microgel hosting cell‐free synthesis of green fluorescent protein. Despite its open, membrane‐free nature, the multifunctional microgel is also able to trap proteins inside its polymer matrix. Read the full text of the Article at 10.1002/syst.201900058 .

Abstract Conceptualising gelators with stimuli responsiveness is advantageous to design smart materials for emerging technologies. These gelators, if are surface active and made up of active pharmaceutical ingredients, can (i) exhibit an interesting pharmaceutical profile, (ii) be useful in drug formulations and (iii) exert direct effects on cell membranes. Herein, cetylpyridinium salicylate (CetPySal) that offers higher surface activity than its precursor surfactant, cetpylpyridinium chloride (CPCl), was synthesised. CetPySal forms a temperature‐responsive ionogel at a critical gelation concentration that changes its physical appearance with temperature, i. e. opaque to transparent, owing to its structural arrangement within its supramolecular framework, that are characterized through spectrometric, calorimetric, scattering and microscopic techniques. The viscoelastic nature of the ionogels was studied through dynamic rheological measurements and the interactions that governs the phase transition were studied through FTIR spectroscopy. The hybrid pharmaceutical ionogels was successfully constructed through encapsulation of the chemotherapeutic drug imatinib mesylate within the ionogel matrix. The sustained release of the drug was investigated from this hybrid ionogel matrix. These results suggest that this new thermo‐responsive ionogel may be used to improve sustained release of drugs and open up new avenues as low‐cost gelators for biomedical applications.

The Front Cover summarizes the discussions of a path-hypothesis to make prebiotic RNA, via mineral-guided maturation of carbonyl species and base precursor formation in a post-impact reduced atmosphere, presented in the review.More information can be found in the Review by S. A. Benner et al.

Abstract Automatic mechanism generation is a powerful approach to understanding complex chemical mechanisms. Here we describe the expansion of an open source mechanism creating software, the Reaction Mechanism Generator or RMG, to oxygenated sulfur systems. This principally involved the expansion of thermochemistry estimation techniques for higher valence oxygenated sulfur molecules. As a demonstration of this new tool, we present an automatically generated mechanism describing the oxidation of dimethyl sulfide. This mechanism is then compared to several experimental studies of dimethyl sulfide oxidation. This case study provides insight into the transformation of sulfur species in the atmosphere, especially the formation pathways of sulfoxides, sulfones, and sulfur dioxide. However, the applications of the newly enhanced mechanism generation tool extend far beyond this single system with obvious use in understanding a variety of atmospheric, petrochemical, and other industrial chemistries.

Abstract Reaction models that accurately describe the complex reaction processes of ignition are key for the development of novel engine‐ and fuel concepts. Since reactive molecular dynamics can be used to discover reaction networks in a largely automated fashion, this method has the potential to drastically reduce the real time effort necessary for the development of reaction models. With standard reactive molecular dynamics, the simulation of low‐temperature reaction processes is hindered by the small accessible time scales of only a few nanoseconds. In this work, we propose the pressure‐accelerated dynamics method to overcome the time scales obstacle through exploitation of Le Chatelier's principle. For the example of pentane low‐temperature ignition, we show that with pressure‐accelerated dynamics, the ReaxFF reactive force field, and the ChemTraYzer not only the known key low‐temperature igniton pathways can be found, but also reactions that are not yet included in reaction models.

Abstract We present a model to describe oscillations and collective behavior in a heterogeneous system of active colloidal clusters whose motility and interactions are driven by an oscillatory chemical reaction, as motivated by experimental observations of collective behavior in silver phosphate clusters under UV light in the presence of hydrogen peroxide, where spatio‐temporal correlations in cluster behavior are presumably modulated by diffusive communication between clusters. A generic model for a single bistable cluster becomes oscillatory upon introduction of inter‐cluster interactions that relate to localized emission or consumption of diffusing species. Multi‐cluster simulations capture the qualitative features in the experimentally observed spatio‐temporal correlations in the oscillations of nearby clusters. Since the model is generic and does not rely upon a particular chemical mechanism, it can be applied to other active matter systems exhibiting collective behavior, where interactions between bistable entities can drive collective oscillations.