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The air–water interface plays a crucial role in microdroplet reactions. In this study, we investigated the oxidation of two thiol molecules on water microdroplets: 2-mercaptosuccinic acid (MSH) and 3-phenyl-2-sulfanylpropanoic acid (PSH), with PSH being much more amphiphilic than MSH. Mass spectrometric experiments showed much higher oxidation yields of PSH compared to MSH. Theoretical results indicated that PSH anions preferentially partitioned to the air–water interface, but MSH anions showed no enrichment trend, which is consistent with the experimental results. This study highlights the central importance of the air–water interface in microdroplet reactions.

Herein, we present a family of 7-(diethylamino)coumarin-3-carboxamides, bearing three different aza-crown moieties (chelating unit). All synthesized compounds have shown a colorimetric response and fluorescence ON–OFF behavior to the presence of lead, calcium, magnesium, and copper, with higher affinity toward the latter, even in the presence of other cations in solution. Optical spectroscopies, X-ray crystallography, and EPR experiments show that Cu(II) induces an irreversible oxidation on the coumarin core, with the concomitant formation of Cu(I) and an organic radical species. The emergence of an absorption band in the visible region upon radical formation results in the appearance of blue color, which fades over time, highlighting the potential of these sensors for rapid detection of copper(II) ion under the naked eye.

Information handling at the molecular level can be achieved by appropriate control of the chiroptical response of a chromophore. In this context, a dynamic Möbius aromatic π-system, embedded in a 3-type chirality totem edifice, has been investigated, targeting a time-dependant protonation control of its stereoselective winding. The mono-protonation of the so-called hexaphyrin-cyclodextrin hybrid (HCD) was therefore carried out with either stable (e.g. methanesulfonic acid) or unstable (trichloroacetic acid [TCA]) acids producing a drastic increase of the chiroptical activity resulting from a favored M-twist (d.e. ∼75%). Using TCA, the mono-protonation becomes a transient state, turning the static chiroptical response into a dynamic one whose time domain varies from minutes to hours, depending on the solvent composition or the amount of acid. More importantly, the way-back process (back deprotonation), that relies on the decomposition of the Cl₃CCO₂^– counter-anion, was significantly accelerated by exchange with Cl^–. As a result, addition and trapping of Cl^– anion allows to switch between a dissipative and a static chiroptical response of the TCA induced mono-protonated species. This remarkable temporal control over a chiroptical signal paves the way for the design of Möbius-type devices for molecular encoding and signaling.

The development of organic dyes is crucial for high-tech technologies such as displays, telecommunication, and anticounterfeiting. While rylene diimides such as naphthalene and perylene diimides (NDIs and PDIs) exhibit promising optical properties, their crystalline and brittle nature can limit their suitability for flexible or integrated applications. In this work, we display the design and synthesis of both achiral and chiral molecules based on a perylene diimide dye, in conjunction with discrete oligomers of dimethyl siloxane. These molecules phase-separate into processable, well-defined columnar nanostructures with sub-5 nm periodicity. When deposited onto silicon nanorod metasurfaces, both dyes exhibit strongly polarized and directional luminescence (g_lum = 1.09) as a result of the coupling of the emission to optical modes, which are absent without the metasurface. This chiral emission emerges because, at oblique angles of incidence, the metasurface–molecule system becomes extrinsically chiral, no longer being superimposable with its mirror image. These findings demonstrate that highly asymmetric emission can be achieved from intrinsically achiral molecules, which are often synthetically less burdensome compared to their chiral counterparts.

The quest to model carbyne has been largely tackled through increasingly longer polyynes. [n]Cumulenes are an alternative class of molecules to model carbyne. The major difference between polyynes and cumulenes is that polyynes maintain strong bond length alternation (BLA) while cumulenes do not. The development of longer [n]cumulenes is challenged by decreased stability relative to oligoynes. This study compares the persistence of tetraaryl[n]cumulenes based on ortho-substituent(s) of aryl endgroups. A trend emerges in which bulkier ortho-substituents offer more persistent [n]cumulenes. The enhanced stability is consistent with a combination of steric shielding and disrupted electronic communication between the endgroups and cumulenic framework. Kinetically stabilized [n]cumulenes [n]otBu (n = 5, 7, 9, 11, 13) are successfully synthesized. The longest derivatives, [11]otBu and [13]otBu, are studied in solution, and the electronic absorption properties are compared experimentally and computationally. The terminal alkylidene groups of [n]cumulenes have significant effects on the optical properties and result in an additional optical state, S₁, relative to oligoynes. The S₁ state gives a lower fundamental optical energy gap (E_g) in [n]cumulenes relative to oligoynes and decreases as the molecules transition from D₂ to D_∞h symmetry. The highest energy state (S₄) is allowed by symmetry at any length and shows remarkable similarity to the analogous absorptions of polyynes.

The molecular recognition features of a glycomimetic (9-Ad-6SL), selective toward Siglec-10, a sialic acid-binding immunoglobulin-like lectin involved in immune regulation, have been unraveled using a combination of experimental NMR methods and computational chemistry protocols. Given the presence of two arginine residues within the shallow binding site—canonical R119 and noncanonical R127—both of which engage the carboxyl group of sialic acid, the interaction of the glycomimetic with the corresponding Arg-to-Ala mutants (R119A, R127A) of Siglec-10 has also been evaluated. The obtained results demonstrate that, at least for Siglec-10, the presence of large hydrophobic groups in the glycomimetic strongly influences the molecular recognition process. In addition, these findings reveal the intricacy for establishing a rational structure-based ligand design for Siglec-10 with the potential to be used for therapeutic targeting in cancer immunotherapy.

TeHyperBTM [= (2S,3R)-3-isopropyl-2-phenyl-3,4-dihydro-2H-benzo[4,5][1,3]tellurazolo[3,2-a]pyrimidine] is introduced as a novel, highly effective, chiral, Lewis basic isochalcogenourea organocatalyst. Compared to its established sulphur- and selenium-based homologues HyperBTM and SeHyperBTM, the increased nucleophilicity and Lewis basicity of TeHyperBTM directly impact its catalytic performance by increasing reaction rates and often also improving enantioselectivities for organocatalytic (4 + 2)-cycloadditions between Michael acceptors and electron-deficient allenes or alkynes. Furthermore, less reactive reagents, such as diethyl allenylphosphonate or ethyl but-2-ynoate, that were not sufficiently activated by HyperBTM and SeHyperBTM catalysts, underwent smooth (4 + 2)-cycloadditions with Michael acceptors when using TeHyperBTM as the catalyst, which underscores the high catalytic potential of this novel chiral highly nucleophilic Lewis base.

Despite significant advances in the development of C-centered, axial, or planar chiral phosphine ligands in asymmetric catalysis, P-chiral monodentate phosphine ligands remain underexplored. Especially in gold catalysis, monodentate P-chiral phosphine ligands have not been employed because of the inherent geometrical challenges. In this article, the synthesis of new monodentate P-chiral phosphine ligands is presented, which bear substituted biaryl units. The approach is based on desymmetrization of alkyl(diphenyl)phosphine oxides by directed ortho-metalation and iodination. The enantioenrichment was achieved by crystallization. The biaryl unit was formed by a Suzuki–Miyaura coupling. Stereoretentive reduction by Ti(OiPr)₄/hydrosilane gave the phosphines, which were transformed in situ to stable chiral gold(I) complexes, which were characterized by X-ray crystallography and spectroscopic methods. The complexes were applied in asymmetric cycloisomerization reactions of diverse 1,6-enynes providing tricyclic 5/6/6 compounds in good to excellent yields, good regioselectivity, and mostly high enantioselectivity. Hexafluoroisopropanol (HFIP) proved to be optimal as the solvent and activator since it enabled direct application of the gold chloride complexes and proved beneficial to achieve high reactivity and asymmetric induction. The method was applied to the synthesis of a podophyllotoxin analog, which proved to be moderately active against selected cancer cell lines but not against normal human cells.

The introduction of stimulus-responsive groups can give polymers some material properties that cannot be realized simply by design and synthesis. Polyolefins, due to their nonpolar nature, suffer from poor compatibility with polar materials; however, directly grafting polar groups like hydroxyls onto their surface via traditional synthesis risks compromising their intrinsic hydrophobicity and is further hindered by challenges such as poisoning effects on catalysts from polar moieties. In this work, a photoresponsive strategy for polyolefins that enables surface introduction of hydroxyl groups without altering the bulk properties has been introduced. By copolymerizing ethylene with acrylate-based comonomers, we synthesized functional polyolefins capable of undergoing photo-Fries rearrangement under both UV and natural sunlight irradiation. This process selectively generates reactive phenolic hydroxyl groups at the material surface. The phototreated polymers exhibit significantly improved surface properties, including enhanced hydrophilicity, dyeability, and interfacial adhesion to metals. Additionally, we demonstrate a scalable route to these photoresponsive polyolefins via post-functionalization of commercial maleic anhydride-grafted polyolefins, establishing a versatile platform for further customization. This work highlights how light responsiveness can overcome the constraints of traditional synthesis to achieve cross-scale structural control in polymers.

Post-transcriptional modifications play a pivotal role in regulating the health and physiology of human cells, and adenosine-to-inosine (A-to-I) editing is one of the most abundant of these modifications. Inosine is read as guanosine by the cellular machinery, and this change impacts both the regulation and genetic code of RNA, in turn effectively rewiring both the transcriptome and proteome. Given these crucial functions, it is not surprising that A-to-I editing is implicated in a number of disease processes, including cancers and neurological disorders. While adenosine deaminases acting on RNA have been identified as the primary writers for inosine modification, putative readers and erasers have received far less attention. Recent studies have revealed that the Endonuclease V (EndoV) family of enzymes has the unique ability to detect and cleave inosine-containing RNAs, suggesting that EndoV may regulate the fate of edited RNAs in the cell. Despite this potentially important role, human Endonuclease V (hEndoV) remains relatively understudied, and in some cases, conflicting results have been presented regarding the activity of hEndoV. Here, we aim to bring together this existing knowledge in order to further spur investigation into this potentially crucial regulator of A-to-I editing. We first describe biochemical and structural studies that reveal the molecular aspects of inosine recognition and RNA cleavage and the evolution of these functions from DNA repair in prokaryotes to RNA cleavage in eukaryotes. Based upon this knowledge, we discuss reports suggesting the role of hEndoV in human physiology. Finally, we highlight technologies that leverage EndoV for mapping and quantifying A-to-I editing in vitro and in cells and tissues.