We report a photoredox-catalyzed, redox-neutral [3+2] annulation of cyclopropanols with electron-deficient alkenes that integrates proton-coupled electron transfer (PCET) activation and a radical-polar crossover sequence within a single catalytic cycle. PCET oxidation of cyclopropanols generates beta-keto radicals, which add to activated alkenes and undergo single-electron reduction to form carbanion intermediates, enabling intramolecular aldol-type cyclization to furnish densely substituted cyclopentanols under mild conditions. Dehydroalanine derivatives serve as particularly effective partners, delivering cyclic alpha,alpha-disubstituted amino-acid and peptide derivatives with high diastereoselectivity while accommodating primary, secondary, and tertiary radical precursors. Acrylates, acrylonitriles, maleimides, and 1,1-diarylethylenes are also compatible substrates. This redox-neutral catalytic platform expands the synthetic utility of cyclopropanols as ambiphilic three-carbon building blocks, enabling streamlined access to functionalized five-membered carbocycles.

The realization of isolated quantum systems within solid-state matrices is a pivotal challenge in quantum information science. This study demonstrates the existence of a "nano-vacuum" state in lithium-ion endohedral fullerene (Li+@C60·PF6 -), where the encapsulated ion exhibits extreme magnetic isolation. Using ultrahigh field (18.79 T) solid-state NMR, we observed a 7Li line width of ∼50 Hz that remains invariant under magic angle spinning (MAS), indicating that the ion undergoes ultrafast isotropic motion (τc ≪ 10-5 s), which completely averages quadrupolar interactions. Most significantly, we report a record-breaking spin-lattice relaxation time (T 1) of approximately 1068 s. This extraordinary lifetime is rationalized by a "relaxation blockade" mechanism: the absence of spin-orbit coupling prevents phonon scattering, while the rapid "roaming" of Li+ and the cooperative "plastic" rotation of external PF6 - anions synergistically suppress dipolar and quadrupolar relaxation channels. These findings establish Li+@C60 as a ″thermodynamically open but magnetically closed″ system, offering a robust platform for quantum sensing.

Fully substituted acyclic enolates are valuable intermediates for the enantioselective construction of α-quaternary carbonyl compounds, yet reliable control of enolate geometry-particularly for aldehydes-remains difficult under conventional deprotonation conditions. β-Oxy vinylbenziodoxoles (VBXs), accessible through two complementary pathways, provide stereodefined acyclic enolate precursors that retain alkene geometry through subsequent cross-coupling and carbonate formation. These VBXs undergo configuration-retentive Sonogashira coupling, enabling modular installation of alkynyl substituents. Subsequent conversion to allyl enol carbonates furnishes ketone- and aldehyde-type enolate surrogates with defined E/Z configuration. Under Pd/Trost-ligand conditions, these carbonates participate in enantioselective decarboxylative allylic alkylation to deliver α-quaternary ketones and aldehydes in high yields and enantioselectivities. The decisive role of enolate geometry is demonstrated by the opposite sense of asymmetric induction for E- and Z-isomers of the carbonate precursor. The resulting alkynyl-substituted products are readily diversified through manipulation of the allyl, alkynyl, and carbonyl groups.

Carboiodanation of arynes with organo-benziodoxoles (BXs) furnishes aryl-BXs (ArBXs) bearing ortho-alkynyl, alkenyl, or aryl groups, which serve as versatile aromatic building blocks for downstream pi-extension through the aryl-iodine(III) bond. Although synthetically valuable, these primary carboiodanation products rarely participate in a second aryne addition due to insufficient nucleophilicity. Here we show that judicious pairing of organo-BXs and arynes enables electronic activation of the initial ArBX product, rendering it competent for a second carboiodanation to afford biaryl-BX derivatives. This unique reactivity arises from a BX-specific arenium/iodate four-membered cyclic intermediate, in which the positive charge is efficiently delocalized by mesomeric effects provided by substituents transferred from beta-alkoxyvinyl-BXs (VBXs) and ethynyl-BXs (EBXs), as well as the electron-rich aryl framework formed upon initial aryne incorporation. The resulting biaryl-BX scaffolds provide concise access to densely functionalized oligoarylenes and polycyclic aromatic frameworks.

Site-selective connection of peptides is crucial for constructing structurally uniform peptide chimeras bearing multiple functions, for applications such as drug discovery and drug delivery. However, the site-specific connection of two peptides is challenging due to the need to pinpoint two reaction sites among the multiple nucleophilic sites, such as lysine epsilon-amines. In this work, we developed a peptide-peptide coupling method involving an Ag-catalyzed N-terminus/dehydroalanine (Dha)-selective 1,3-dipolar cycloaddition reaction, yielding peptide chimeras with exclusive endo diastereoselectivity. The use of (S)- and (R)-DTBM-SEGPHOS as chiral ligands enables control over the stereochemistry of the pyrrolidine ring, irrespective of the inherent stereochemistry of the peptides, demonstrating its utility for the late-stage installation of cyclic chiral alpha,alpha-disubstituted amino acid residues into peptides. The versatility of this method was further demonstrated through the selective generation of a Dha moiety from various amino acid residues, followed by [3 + 2] cycloaddition. Notably, generation of the N-terminal imine, exposure of the Dha residue, and [3 + 2] cycloaddition can be performed in a convergent manner using two distinct peptides and an aldehyde, without isolating each intermediate, enabling their expedient assembly into a chemically robust pyrrolidine ring.

Cyclic diaryliodonium salts are versatile intermediates for the synthesis of functionalized aromatic compounds and polycyclic systems. Their preparation, however, typically relies on oxidative cyclization of preorganized iodoaryl-aryl frameworks, and medium-sized cyclic diaryliodoniums remain largely underexplored within this synthetic paradigm. Here we report an aryne-mediated direct assembly of O-bridged seven-membered cyclic diaryliodoniums from (pseudo)cyclic diaryliodoniums bearing an O-nucleophilic benzyl alcohol-derived ligand and a dummy 2,4,6-trimethoxyphenyl ligand. The transformation involves aryne engagement of the oxygen and intramolecular ambiphilic capture by the iodine(iii) center, followed by protonation of the dummy ligand to furnish the cyclic diaryliodonium products. These cyclic diaryliodoniums serve as versatile platforms for skeletal modification, enabling access to oxaheteropine frameworks through iodine replacement and a concise synthesis of cannabinol via iodine deletion.

The development of electron-transporting n-type organic semiconductors (OSCs) has lagged behind that of hole-transporting p-type OSCs, owing to the limited number of molecules that combine air stability with high electron mobility. The electron mobility of n-type OSCs is governed by the spatial extent of the lowest unoccupied molecular orbital (LUMO), particularly the orbital overlap between adjacent molecules. Therefore, controlling arrangements is essential for achieving high electron mobility. The current work focused on molecular salts composed of naphthalene diimides (NDIs), with air stability and relatively high electron mobility, modulating the molecular arrangement and elucidating its relationship with electronic properties. An NDI dicarboxylic acid was synthesized by introducing carboxyl groups with a methylene spacer to minimize the influence on the electronic state of NDIs. As the carboxyl group has low acidity, molecular salts were prepared using strongly basic amines. Depending on the type of amines, the molecular arrangement of NDIs was modulated through strong hydrogen bonds. As a result, a slipped-parallel stacking arrangement with varied interplanar and centroid-to-centroid distances between adjacent NDIs was obtained. In addition, a quasi-orthogonal slipped-stacking arrangement, unprecedented for NDI derivatives, was realized. Calculated transfer integrals between adjacent molecules revealed that slipped-parallel stacking is more favorable for electron transport than quasi-orthogonal slipped-stacking. In addition, it was revealed that, within similar slipped-parallel stacking arrangements, the arrangement with a larger overlap of pi-conjugation is more favorable for efficient electron transport. The current work demonstrates an NDI molecular arrangement that enables efficient electron transport by modulating the molecular arrangement and analyzing the intermolecular interactions.

Lithium-ion encapsulated fullerene (Li+@C60) represents a novel class of ionic endohedral metallofullerenes possessing distinct electronic properties, including high ionic conductivity and superior electron-accepting capabilities compared to pristine C60. While the "plasma shower" ion implantation method has enabled the continuous synthesis of Li+@C60, the industrial application of this material is currently impeded by a critical disparity between the theoretical synthesis yield and the actual recovered yield. Current extraction protocols typically recover only approximately 0.8% of Li+@C60, which is significantly lower than theoretical predictions. This study aims to rigorously quantify the Li+@C60 content in the postsynthesis crude soot to determine the true efficiency of the plasma shower synthesis and identify the physicochemical factors limiting extraction. We employed a multifaceted analytical approach combining Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS), solid-state 7Li Nuclear Magnetic Resonance (NMR) spectroscopy, and Inductively Coupled Plasma (ICP) analysis. Quantitative analysis based on three independent synthesis runs (N = 3) reveals that the crude soot contains Li+@C60 at a mass percentage of 3.4 ± 0.1%. Furthermore, spectral analysis identified a significant abundance of oxidized derivatives (Li+@C60O, 4.3 ± 0.1%), indicating a total encapsulation efficiency of 7.7% ± 0.1%. Additionally, Transmission Electron Microscopy (TEM) revealed the formation of robust clusters with a median diameter of approximately 8 nm. Collectively, these findings confirm that the low recovery in conventional methods (∼0.8%) is not due to synthesis failure, but rather due to the formation of insoluble aggregates and oxidative derivatives. This report provides a detailed quantitative framework for evaluating Li+@C60 synthesis and proposes that optimizing physical disintegration techniques, such as dual-frequency ultrasonication, alongside strict oxidation control, is essential for bridging the yield gap.

Algal organic matter (AOM) released during cyanobacterial blooms can significantly challenge drinking-water treatment, including an elevated risk of disinfection byproduct (DBP) formation, yet the molecular-scale fate of bloom-derived AOM through treatment remains poorly constrained. Here, we integrated ultrahigh-resolution FT-ICR MS with paired-mass-difference (PMD) reactomics and interpretable machine learning (IML) to resolve (i) bloom-driven molecular transformations, (ii) selective removal by coagulation (COA) and granular activated carbon (GAC), (iii) formula-level chlorination reactivity and DBP formation. Laboratory bloom simulations using Microcystis aeruginosa resulted in the detection of 3373 bloom-derived formulas enriched in nitrogen and reduced character (higher N/C and H/C; lower O/C and aromaticity). Reactomics networks indicated dominant putative transformations involving CHO moieties (e.g., CH2, CO, CH2O) and amine-related changes, with prominent amino-acid-like mass differences. COA (polyferric sulfate) and GAC both substantially reduced bulk dissolved organic carbon (DOC) but generated distinct residual molecular spaces: COA treatment left lower-molecular-weight (MW) and higher-aromatic index (AImod) residues than that of GAC. Supervised ML models identified MW and heteroatom ratios (N/C, S/C, O/C) as key predictors of operationally defined formula-level reactivity following chlorination. Correspondingly, chlorination generated matrix- and treatment-dependent chlorinated organic compounds (COCs), including nitrogen-containing chlorinated features uniquely detected in AOM-containing waters. These findings demonstrate that conventional treatment processes, while effective at reducing bulk organic matter, leave distinct residual precursor pools that can alter COCs formation under bloom conditions. This molecular-level framework provides new insights into precursor-level compositional changes and offers a basis for evaluating DBP formation and precursor control strategies in cyanobacterial bloom-impacted drinking-water system.

Disulfide bonds are key structural motifs in bioactive natural products, linker chemistry, and functional materials; however, the selective synthesis of unsymmetrical disulfides remains a significant challenge. In particular, the dithiofunctionalization of C-C unsaturated bonds is underdeveloped, despite its promise for introducing additional molecular complexity. In this work, we report an acid-mediated dithiocyclization strategy for the preparation of heterocycle-appended unsymmetrical disulfides using N-(morpholine-4-dithio)phthalimide. The method applies broadly to nucleophile-tethered alkynes and olefins, affording benzofurans, lactones, cyclic ethers, and pyrrolidines, and it is also amenable to three-component couplings with olefins and TFA. Owing to its wide applicability for 1,2-difunctionalization of C-C unsaturated bonds and the bilateral reactivity of N-(morpholine-4-dithio)phthalimide, this approach provides modular access to heterocycle-appended unsymmetrical disulfides via two consecutive C-SS bond formations. The utility of this method is exemplified by the efficient hybridization of natural product derivatives (e.g., Corsifuran C, Boivinianin A) with bioactive agents (e.g., trimetazidine), highlighting its potential in linker chemistry and drug discovery.

Direct growth of graphene among nanocarbons on catalyst- and seed-free insulators, which offers a technical advance in methodologically straightforward simplicity and avoiding the post-growth transfer process, has been extensively investigated toward evolving a wide range of applications. In this study, plasma-enhanced chemical vapor deposition (PECVD) instead of thermal CVD (TCVD) is adopted for lowering the on-insulator growth temperature and gaining new insight into the fundamental growth-process of 2D graphene in connection with 1D single-walled carbon nanotubes (SWNTs). It is found for the first time that PECVD of low-influx plasmas and—energy ions facing an insulating growth-substrate of naked quartz glass enables SWNTs, single-layer graphene (sGPN), and a few-layers graphene (fGPN) to grow at critical ambient temperature of 700 ℃, where an equilibrium state is sophisticatedly maintained between carbon-source deposition and etching of unwanted materials. This temperature is substantially lower than 1100–1600 ℃ in the cases of TCVD so far. Furthermore, when the plasma influx and ion energy is gradually increased at the same temperature, only the 2D nanocarbon composed of sGPN and turbostratic graphite in the form of a mixture isobserved to grow while SWNTs and fGPN disappear.

A quantitative analysis of the lithium ion-endohedral fullerene salt, Li+@C60·PF6 - (1), was performed using 19F nuclear magnetic resonance (NMR) spectroscopy. To establish a robust quantitative 19F NMR (qNMR) method, experimental parametersincluding spin-lattice relaxation time (T 1), relaxation delay, and offset frequencywere optimized using tetrabutylammonium hexafluorophosphate (TBA+·PF6 -) as a model compound and α,α,α-trifluorotoluene (PhCF3) as an internal standard. The purity of 1 was determined using a calibration curve constructed from 19F NMR measurements, which effectively minimized systematic errors. The purity value obtained via this nondestructive qNMR method was approximately 95%, showing excellent agreement with quantitative results obtained from inductively coupled plasma atomic emission spectroscopy (95.1%). This method offers a rapid, specific, and nondestructive alternative for the purity evaluation of endohedral metallofullerenes allowing for complete sample recovery.

We report here a concise and regioselective synthesis of benzofulvene derivatives via an iodine(III)-mediated cyclization cascade of diynes. For 1,2-dialkynylbenzene substrates, the iodanylative cyclization is accompanied by triflation or fluorination, depending on the iodine(III) reagent, affording stereodefined benzofulvene derivatives. In contrast, the reaction of 1,6-diyne substrates is terminated by intramolecular Friedel-Crafts cyclization to deliver fused benzofulvene frameworks. A representative triyne was also shown to participate in an analogous cascade, furnishing functionalized cyclopenta[cd]indene derivatives. The resulting iodane-functionalized benzofulvenes serve as substrates for Pd-catalyzed cross-coupling and for aryne insertion, the latter being a transformation characteristic of hypervalent iodine chemistry.

In this study, stable tetrazene radical cation salts were synthesized and characterized for the first time. The radical cation derived from 1,2-di(2-azaadamantan-2-yl)diazene (DAD) was isolated as an air-stable solid, retaining its integrity for at least 120 days at ambient temperature (∼25 °C) and pressure. X-ray crystallography and electron spin-resonance spectroscopy revealed the delocalization of the unpaired electron over the tetrazene core and into the adamantane framework. DAD undergoes two well-separated, reversible redox processes and displays high catalytic activity for alcohol oxidation under mild conditions. Systematic structural modifications identified the key framework features governing the radical cation stability and catalytic performance.

The adsorption of perfluoroalkyl acids (PFAAs) is typically attributed to electrostatic interactions of their anionic headgroups and hydrophobicity of their fluorocarbon tails. However, the fluorocarbon chain also exhibits a unique “polar hydrophobicity”, a dual character that could significantly influence surface adsorption chemistry. In this study, we show that conformational variations of PFAAs enable polar interactions between fluorocarbon tails and polarized substrates, thereby manifesting this polar hydrophobicity. Using dispersion-corrected density functional theory (DFT-D) and molecular dynamics (MD) simulations, we found that bent conformers of long-chain PFAAs (also detected by 19F-NMR) interact with electrostatic-hydrophobic interfaces through combined electrostatic (including hydrogen bonding) and van der Waals forces. In contrast, short-chain PFAAs exhibited predominantly headgroup-driven electrostatic adsorption consistent with conventional concepts. These findings demonstrate that conformational dynamics govern the polar hydrophobicity of long-chain PFAAs and their selective adsorption at electrostatic-hydrophobic interfaces, providing molecular-level insights for advanced adsorbent design and improved understanding of PFAS fate and transport in complex environments.

Diazomethyl-λ3-iodanes have recently emerged as carbyne equivalents in organic synthesis, enabling the construction of multi-substituted carbon centers through strategic sequential activation of the diazo and iodane functional groups. Distinct from such reaction modes, we report here on the reactivity of diazomethyl-λ3-iodanes as iodane-bound 1,3-dipoles toward arynes. Equipped with bis(trifluoromethyl)benzyl alcohol-based benziodoxole (BX) moiety, diazomethyl-λ3-iodanes undergo annulation with arynes generated from ortho-silylaryl triflates and cyclic diarylhalonium salts, resulting in indazolyl-λ3-iodanes through [3+2] cycloaddition and carbon-to-nitrogen iodane migration. DFT calculations reveal that diazomethyl-BX prefers [3+2] cycloaddition with aryne over aryne insertion into the carbon–iodine(III) bond (carboiodanation) and that the subsequent iodane migration proceeds through two consecutive 1,5-iodane shifts. The utility of these indazolyl-BXs as indazole-transfer agents has been demonstrated by α-functionalization of N,N-dimethylaniline derivatives.

γ-Amino alcohols are essential motifs in bioactive compounds and chiral catalysts, yet the synthesis of their conformationally constrained variants remains challenging due to the lack of suitable methodologies. Here, we report a formal cyclopropylation of imines with cyclopropanols, enabling the construction of previously inaccessible cyclopropane-embedded γ-amino alcohols. This transformation leverages the unique reactivity of enolized zinc homoenolates, which effectively act as a β-hydroxycyclopropyl anions and engage imines through a sequence of Mannich addition and ring closure. The key to this reactivity lies in the use of bulky N-heterocyclic carbene (NHC) ligands, which promote efficient coupling with N-sulfonyl aldimines as well as chiral N-sulfinyl trifluoromethyl-ketimines while ensuring excellent diastereocontrol over three contiguous stereocenters. Furthermore, the resulting γ-amino alcohols can be transformed into β- or γ-aminofunctionalized ketones via homoenolate or β-keto radical intermediates, offering versatile platforms for downstream derivatization.

Dissolved organic matter (DOM) is a key component of the global carbon cycle, yet its structural complexity has hindered understanding of its transformation and persistency. Here, we present a chemical space refinement strategy that integrates ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), tandem MS (MS2) analysis, and a multi-source network traversal (MSNT) algorithm to curate chemically coherent DOM assemblages. Within this refined chemical space, structural candidates serve as proxies for predicting molecular motifs and physicochemical traits of DOM. Performance evaluation showed that MSNT-refined structures were well consistent with MS2 spectra, and effectively captured the photochemical transformation of lignin-derived DOM (a key terrestrial precursor), leading to the emergence of unique structural features including high-polar carboxyl-rich alicyclic molecule (CRAM)-like and condensed aromatic structures. More broadly, photochemical oxidation of various riverine and terrestrial DOM was shown to reshape chemical space toward more convergent signatures resembling CRAM-like refractory coastal DOM, primarily through dearomatization and carbonylation that proceed concurrently with structural diversification.