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This manuscript introduces a novel approach for quantifying the strength of halogen and chalcogen bonding interactions involving heavy elements of groups 17 (Br, I) and 16 (Se, Te). While X-ray photoelectron spectroscopy (XPS) is a recognized diagnostic tool for halogen bonding, its application for characterizing chalcogen bonds, or quantifying the strength of either interaction via spectral shifts, remains unexplored. To current knowledge, this study is the first to propose and rigorously validate such an approach. A comprehensive benchmark investigation is first conducted to identify the most reliable theoretical methods for reproducing experimental XPS signals. Subsequently, a clear correlation between calculated XPS shifts and the interaction strength is established, demonstrating XPS as a novel and experimentally accessible method. This work aims to significantly advance the understanding and rational design of noncovalent interactions in supramolecular chemistry and materials science.

A protocol for the multigram scale synthesis of the bench stable salt S-(cis-2,3-bis(trifluoromethyl)cyclopropyl)dibenzothiophenium tetrafluoroborate 1 is reported. This compound is used as a versatile reagent for the mild transfer of the cis-2,3-bis(trifluoromethyl)cyclopropyl moiety (cis-BTFC) to structurally complex heterocycles under photochemical conditions. The radical process tolerates a number of functional groups and proceeds with retention of the original cis-configuration. The newly introduced cis-BTFC chemotype is characterized by a van der Waals volume of 115 ų, which sets its steric demand between those of the heptafluoroisopropyl (HFIP, 99 ų) and the perfluorotertbutyl units (PFTB, 128 ų). Notably, the experimentally determined lipophilicity value (Log P) indicates that the cis-BTFC scaffold imparts significant higher polarity to the carrying structure than both HFIP and PFTB, making this motif potentially attractive for the optimization of pharmacokinetic profiles during drug optimization campaigns. Interestingly, under basic treatment, typical N-, O-, or S-nucleophiles also react with 1, but mixtures of the cis- and trans-BTFC containing products are obtained in varying ratios. Mechanistic studies confirm the in situ generation of 1,3-bis(trifluoromethyl)cyclopropane, which subsequently reacts with nucleophiles in a Michael-type fashion.

Helix-sense-selective polymerization (HSSP) is a powerful method for the synthesis of preferred-handed helical macromolecules. This article presents a new method for controlling the HSSP of an achiral 4-alkoxy-3,5-bis(hydroxymethyl)phenylacetylene derivative, using an axially chiral heptaarylhexa-1,3,5-trienylrhodium(I) complex as an initiator. Hydrophobic components, such as a tert-butyl group and tetrafluorobenzobarrelene (tfb) ligand, are introduced into the rhodium complex to increase its solubility in eluents, including n-hexane, and sufficient amounts of enantioenriched samples are obtained by optical resolution using chiral high performance liquid chromatography. The complex is used as an initiator for the HSSP of an achiral 4-alkoxy-3,5-bis(hydroxymethyl)phenylacetylene derivative at a lower temperature. The HSSP proceeds in a controlled manner, yielding the corresponding poly(phenylacetylene) derivative with a molecular weight roughly consistent with the value expected from the feed ratio of the monomer to the initiator. Circular dichroism (CD) spectra of the resultant polymers indicate the formation of a one-handed helical structure in the polymer backbone. The CD intensity of the resultant polymers increases with increasing feed ratio up to ≈150 but gradually decreases beyond that point, indicating that the helical sense of the polymer determined in the initiation step by the chirality of the initiator can persist up to 150 repeating units.

In biology, the specific enzyme-mediated cleavage of peptide and protein backbones plays numerous regulatory roles. Being able to mimic the specificity and efficacy of enzymes, using chemical methods, is a grand challenge. Nevertheless, specific chemical cleavage of protein backbones at cysteine residues dates back to the 1960s. In this concept, recent insights and developments in chemical peptide and protein backbone cleavage as well as their applications for the selective manipulation and functionalization of proteins are discussed.

A ternary metal catalyst system based on Pd/C-Pt/C-Ru/C and molecular oxygen is found to be very effective and robust in oxidizing alcohols to carboxylic acids. Using the ternary catalyst and a flow-setup, the conversion of 5-hydroxymethylfurfural (HMF, 1) to 2,5-furandicarboxylic acid (FDCA, 2), a bioplastics precursor, proceeded quite rapidly with a residence time of 1 min at 120 °C under 0.28 MPa of molecular oxygen. Catalyst activity remains stable for at least 2 weeks, giving 66.8 g (60% yield) of the analytically pure FDCA (2). The ternary catalyst system combined with a flow setup is successfully applied to the rapid conversion of ordinary alcohols 3 to aromatic and aliphatic carboxylic acids 4 in good yields.

Molecular design strategies are essential for rationalizing the aqueous self-assembly behavior of π-conjugated amphiphilic molecules and for clarifying the relationship between their photophysical properties and nanostructure morphology. Despite notable advances in understanding structure–property relationships that enable the selective formation of face-to-face (H-type) and slipped (J-type) aggregates in water, accurately predicting self-assembly outcomes and resulting functions remains challenging. This is partly because the molecular requirements governing other exciton coupling modes, such as oblique-type interactions, and their effects on aggregate morphology are still poorly understood. Herein, a molecular design strategy employing amphiphilic aza-BODIPY dyes that enables precise tuning of exciton coupling (J-type vs oblique) and nanoscale morphology in aqueous environments is presented. By systematically varying both the number and positioning of hydrophilic triethylene glycol chains and the length of hydrophobic alkyl substituents, the structure–property relationships that govern self-assembly behavior, employing a combination of theoretical, spectroscopic, and microscopic methods are elucidated. This work advances the understanding of exciton coupling beyond the well-studied H- and J-type aggregates and provides new design principles for engineering functional materials through supramolecular self-assembly.

Subphthalocyanines (SubPcs) currently hold a privileged position among the most versatile scaffolds for the design of π-conjugated materials. In this context, the remarkable chemical tunability of these macrocycles has played a pivotal role, which has given rise to a unique and rich chemistry over the past two decades. Most recently, postfunctionalization strategies have been successfully applied at the axial ligand, the peripheral positions, and remote sites from the SubPc core. However, each of these approaches requires careful selection of reaction conditions, considering the high sensitivity of SubPcs against strong nucleophiles. In this review, a comprehensive overview of the full synthetic toolbox available for the postfunctionalization of SubPcs is provided. Special emphasis is placed on reaction conditions, functional group tolerance, and structural scope, as well as mechanistic insights when available. Finally, the main synthetic challenges that remain to be addressed in order to fully exploit the potential of SubPc chemistry are outlined. Altogether, this review aims to serve not only as a practical guide for chemists working in the field, but also as an inspiration for future developments in the chemistry of curved π-conjugated systems.

The present contribution comprehensively reviews the coordination chemistry of N-heterocyclic carbene (NHC) bis-phenolate tridentate ligand of the type [OCO] to various metal and heteroatom centers. The structural features of the resulting robust [OCO]M chelates are discussed along with their unique and specific properties, including emerging redox and optical properties of such complexes. Thanks to their stability and electronic features, this class of robust metal chelates has already been exploited for various catalytic applications, most notably the controlled polymerization of polar cyclic monomers and olefins, N₂ reduction and photoinduced catalysis. In addition, some [OCO]M complexes have also been shown to stoichiometrically activate/functionalize small molecules such as O₂ and NH₃. All these aspects, some of them just emerging, are discussed herein along with future research opportunities on [OCO]M chelates.

Organic mechanochemistry is currently undergoing rapid advances, significantly contributing to sustainability and green chemistry by eliminating toxic organic solvents. This discipline can further contribute to sustainability and safety by allowing the use of well-chosen, safer, and easier-to-handle reactants, e.g., solid reagents. The solvent-free conditions inherent to mechanochemistry enhance, in many cases, the reactivity of these solid reagents, which would otherwise be ineffective in solution, representing a new paradigm for organic reactions. This Minireview aims to emphasize the synergistic benefits of mechanochemistry and solid reagents in replacing hazardous substances typically used in organic synthesis. It will also highlight examples of well-known reactions that have experienced notable improvements in reactivity or selectivity using safer solid bases, acids, or gas surrogates. This represents an important transformative shift toward greener and safer methodologies in the field of organic chemistry.

Unusually high coordination number for elements has been of great interest in chemistry. Herein, a new class of hexacoordinated carbon compounds with stoichiometry MCF₆ (M = Ca, Sr) at 400 and 500 GPa and K₂CF₆ at 500 GPa is found using crystal structure predictions assisted by first-principles calculations. . At high pressure, MCF₆ (M = Ca, Sr) adopts a trigonal structure (R $$) that is isomorphous with several other species with M^IIA^IVF₆ (A = Si, Ge, and Sn) while K₂CF₆ adopts a trigonal structure (P$$m1) akin to M₂^IA^IVF₆. Both the species are thermodynamically more stable than the bicomponent MF₂/KF…CF₄ mixture at high-pressure region. These solid-state structures are dynamically stable over a wide range of pressure. For all cases, the main building block of the solid-state structures is the [CF₆]²⁻ unit in which carbon attains a perfectly octahedral coordination of the six fluoride anions. The present study establishes new fluorine-rich carbon compounds and predicts a new class of perfectly hexacoordinated carbon species. For the first time, the stabilization of [CF₆]²⁻ in the solid-state is reported.