Ortho-functionalized pyridinyl-tetrazines break the inverse correlation between click reactivity and cleavage yields in click-to-release chemistry.

The bioorthogonal tetrazine-triggered cleavage of trans-cyclooctene(TCO)-linked payloads has strong potential for widespread use in drug delivery and in particular in click-cleavable antibody-drug conjugates (ADCs). However, clinical translation is hampered by an inverse correlation between click reactivity and payload release yield, requiring high doses of less reactive tetrazines to drive in vivo TCO reactions and payload release to completion. Herein we report that the cause for the low release when using the highly reactive bis-(2-pyridinyl)-tetrazine is the stability of the initially formed 4,5-dihydropyridazine product, precluding tautomerization to the releasing 1,4-dihydropyridazine tautomer.

Chirality-Induced Magnetic Polarization by Charge Localization in a Chiral Supramolecular Crystal.

The chirality-induced spin selectivity (CISS) effect is a fascinating phenomenon that correlates the molecular structure with electron spin-polarization (SP). Experimental procedures to quantify the spin-filtering magnitude have extensively used magnetic-field-dependent conductive AFM. In this work chiral crystals of imide-substituted coronene bisimide ((S)-CBI-GCH) are studied to explain the dynamics of the current-voltage I - V spectra and the origin of superimposed peaks are investigated.

Transferable, Living Data Sets for Predicting Global Minimum Energy Nanocluster Geometries.

Modeling of nanocluster geometries is essential for studying the dependence of catalytic activity on the available active sites. In heterogeneous catalysis, the interfacial interaction of the support with the metal can result in modification of the structural and electronic properties of the clusters. To tackle the study of a diverse array of cluster shapes, data-driven methodologies are essential to circumvent prohibitive computational costs.

Unravelling CO Activation on Flat and Stepped Co Surfaces: A Molecular Orbital Analysis.

Structure sensitivity in heterogeneous catalysis dictates the overall activity and selectivity of a catalyst whose origins lie in the atomic configurations of the active sites. We explored the influence of the active site geometry on the dissociation activity of CO by investigating the electronic structure of CO adsorbed on 12 different Co sites and correlating its electronic structure features to the corresponding C-O dissociation barrier. By including the electronic structure analyses of CO adsorbed on step-edge sites, we expand upon the current models that primarily pertain to flat sites.

Descriptor for CN-Supported Single-Cluster Catalysts in Bifunctional Oxygen Evolution and Reduction Reactions.

Developing highly active cluster catalysts for the bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is significant for future renewable energy technology. Here, we employ first-principles calculations combined with a genetic algorithm to explore the activity trends of transition metal clusters supported on CN. Our results indicate that the supported clusters, as bifunctional catalysts for the OER and the ORR, may outperform single-atom catalysts.

The Promoting Role of Ni on InO for CO Hydrogenation to Methanol.

Ni-promoted indium oxide (InO) is a promising catalyst for the selective hydrogenation of CO to CHOH, but the nature of the active Ni sites remains unknown. By employing density functional theory and microkinetic modeling, we elucidate the promoting role of Ni in InO-catalyzed CO hydrogenation. Three representative models have been investigated: (i) a single Ni atom doped in the InO(111) surface, (ii) a Ni atom adsorbed on InO(111), and (iii) a small cluster of eight Ni atoms adsorbed on InO(111).

Structure Sensitivity of CO Conversion over Nickel Metal Nanoparticles Explained by Micro-Kinetics Simulations.

Nickel metal nanoparticles are intensively researched for the catalytic conversion of carbon dioxide. They are commercially explored in the so-called power-to-methane application in which renewably resourced H reacts with CO to produce CH, which is better known as the Sabatier reaction. Previous work has shown that this reaction is structure-sensitive.

Near-Unity Electrochemical CO to CO Conversion over Sn-Doped Copper Oxide Nanoparticles.

Bimetallic electrocatalysts have emerged as a viable strategy to tune the electrocatalytic CO reduction reaction (eCORR) for the selective production of valuable base chemicals and fuels. However, obtaining high product selectivity and catalyst stability remain challenging, which hinders the practical application of eCORR. In this work, it was found that a small doping concentration of tin (Sn) in copper oxide (CuO) has profound influence on the catalytic performance, boosting the Faradaic efficiency (FE) up to 98% for carbon monoxide (CO) at -0.

What Happens at Surfaces and Grain Boundaries of Halide Perovskites: Insights from Reactive Molecular Dynamics Simulations of CsPbI.

The commercialization of perovskite solar cells is hindered by the poor long-term stability of the metal halide perovskite (MHP) light-absorbing layer. Solution processing, the common fabrication method for MHPs, produces polycrystalline films with a wide variety of defects, such as point defects, surfaces, and grain boundaries. Although the optoelectronic effects of such defects have been widely studied, the evaluation of their impact on the long-term stability remains challenging.

On the Potential of Gallium- and Indium-Based Liquid Metal Membranes for Hydrogen Separation.

The concept of liquid metal membranes for hydrogen separation, based on gallium or indium, was recently introduced as an alternative to conventional palladium-based membranes. The potential of this class of gas separation materials was mainly attributed to the promise of higher hydrogen diffusivity. The postulated improvements are only beneficial to the flux if diffusion through the membrane is the rate-determining step in the permeation sequence.

Ni-In Synergy in CO Hydrogenation to Methanol.

Indium oxide (InO) is a promising catalyst for selective CHOH synthesis from CO but displays insufficient activity at low reaction temperatures. By screening a range of promoters (Co, Ni, Cu, and Pd) in combination with InO using flame spray pyrolysis (FSP) synthesis, Ni is identified as the most suitable first-row transition-metal promoter with similar performance as Pd-InO. NiO-InO was optimized by varying the Ni/In ratio using FSP.

Enumerating Active Sites on Metal Nanoparticles: Understanding the Size Dependence of Cobalt Particles for CO Dissociation.

Detailed understanding of structure sensitivity, a central theme in heterogeneous catalysis, is important to guide the synthesis of improved catalysts. Progress is hampered by our inability to accurately enumerate specific active sites on ubiquitous metal nanoparticle catalysts. We employ herein atomistic simulations based on a force field trained with quantum-chemical data to sample the shape of cobalt particles as a function of their size.

Atomistic Insights Into the Degradation of Inorganic Halide Perovskite CsPbI: A Reactive Force Field Molecular Dynamics Study.

Halide perovskites make efficient solar cells but suffer from several stability issues. The characterization of these degradation processes is challenging because of the limited spatiotemporal resolution in experiments and the absence of efficient computational methods to study these reactive processes. Here, we present the first reactive force field for molecular dynamics simulations of the phase instability and the defect-induced degradation in CsPbI.

Consequences of Amide Connectivity in the Supramolecular Polymerization of Porphyrins: Spectroscopic Observations Rationalized by Theoretical Modelling.

The correlation between molecular structure and mechanism of supramolecular polymerizations is a topic of great interest, with a special focus on the pathway complexity of porphyrin assemblies. Their cooperative polymerization typically yields highly ordered, long 1D polymers and is driven by a combination of π-stacking due to solvophobic effects and hydrogen bonding interactions. Subtle changes in molecular structure, however, have significant influence on the cooperativity factor and yield different aggregate types (J- versus H-aggregates) of different lengths.

Linear Activation Energy-Reaction Energy Relations for LaBO (B = Mn, Fe, Co, Ni) Supported Single-Atom Platinum Group Metal Catalysts for CO Oxidation.

Single-atom catalysts are at the center of attention of the heterogeneous catalysis community because they exhibit unique electronic structures distinct from nanoparticulate forms, resulting in very different catalytic performance combined with increased usage of often costly transition metals. Proper selection of a support that can stably keep the metal in a high dispersion is crucial. Here, we employ spin-polarized density functional theory and microkinetics simulations to identify optimum LaBO (B = Mn, Fe, Co, Ni) supported catalysts dispersing platinum group metals as atoms on their surface.

Design of Nonideal Eutectic Mixtures Based on Correlations with Molecular Properties.

In this work, a statistical analysis was performed to reveal how the molecular properties are correlated with the nonideal behavior observed in eutectic mixtures. From this, a statistical model, combined with theory and experimental results, was developed to predict the nonideal behavior of a specific set of eutectic mixtures, consisting of quaternary ammonium bromides with dicarboxylic acids and polyols. The combination of this analysis and this model can be considered as a first step toward the design of eutectic mixtures.

Bioorthogonal Tetrazine Carbamate Cleavage by Highly Reactive -Cyclooctene.

The high rate of the 'click-to-release' reaction between an allylic substituted -cyclooctene linker and a tetrazine activator has enabled exceptional control over chemical and biological processes. Here we report the development of a new bioorthogonal cleavage reaction based on -cyclooctene and tetrazine, which allows the use of highly reactive -cyclooctenes, leading to 3 orders of magnitude higher click rates compared to the parent reaction, and 4 to 6 orders higher than other cleavage reactions. In this new pyridazine elimination mechanism, wherein the roles are reversed, a -cyclooctene activator reacts with a tetrazine linker that is substituted with a methylene-linked carbamate, leading to a 1,4-elimination of the carbamate and liberation of a secondary amine.

Supramolecular interactions between catalytic species allow rational control over reaction kinetics.

The adaptivity of biological reaction networks largely arises through non-covalent regulation of catalysts' activity. Such type of catalyst control is still nascent in synthetic chemical networks and thereby hampers their ability to display life-like behavior. Here, we report a bio-inspired system in which non-covalent interactions between two complementary phase-transfer catalysts are used to regulate reaction kinetics.

Understanding carbon dioxide activation and carbon-carbon coupling over nickel.

Carbon dioxide is a desired feedstock for platform molecules, such as carbon monoxide or higher hydrocarbons, from which we will be able to make many different useful, value-added chemicals. Its catalytic hydrogenation over abundant metals requires the amalgamation of theoretical knowledge with materials design. Here we leverage a theoretical understanding of structure sensitivity, along with a library of different supports, to tune the selectivity of methanation in the Power-to-Gas concept over nickel.

Reversible Restructuring of Silver Particles during Ethylene Epoxidation.

The restructuring of a silver catalyst during ethylene epoxidation under industrially relevant conditions was investigated without and with vinyl chloride (VC) promotion. During non-VC-promoted ethylene epoxidation, the silver particles grow and voids are formed at the surface and in the bulk. Electron tomography highlighted the presence of voids below the Ag surface.