{"title":"Room-Temperature Paramagnetic-to-Diamagnetic Switching Behavior in an Open-Shell Ionic Liquid with a Tetracyanoquinodimethane Radical Anion Salt.","authors":"Ruifeng Shu, Takeshi Naota, Masatoshi Kozaki, Daisuke Shiomi, Shuichi Suzuki","doi":"10.1002/chem.202501449","DOIUrl":"https://doi.org/10.1002/chem.202501449","url":null,"abstract":"<p><p>An ionic liquid consisting of a 7,7,8,8-tetracyanoquinodimethane (TCNQ) radical anion and a tetra-n-octylphosphonium ion, 1<sup>+</sup>•TCNQ<sup>•-</sup>, undergoes a transformation near room temperature from paramagnetic liquid to diamagnetic solid accompanied by significant changes in photophysical properties. A blue solid of 1<sup>+</sup>•TCNQ<sup>•-</sup> melts upon heating above 328 K, yielding a green liquid. The green liquid exhibits a magnetic susceptibility of 5 × 10<sup>-4</sup> emu mol<sup>-</sup> <sup>1</sup>. Upon cooling, the liquid retains its paramagnetic properties until the temperature reaches approximately 300 K. Upon further cooling below 300 K, the paramagnetic liquid reverts to the initial blue solid. The solid form of 1<sup>+</sup>•TCNQ<sup>•-</sup> exhibits near-zero magnetic susceptibility. The thermal hysteresis loop with magnetic bistability is observed without decomposition over the temperature range from 300 to 328 K. Crystal structure analysis, electron spin resonance (ESR), and electronic spectra indicate that the drastic changes in magnetic properties are attributable to the reversible π-dimerization of TCNQ<sup>•</sup> <sup>-</sup> species during the solid-liquid/liquid-solid phase transitions. Additionally, the association/dissociation behaviors of the TCNQ<sup>•</sup> <sup>-</sup> dimers also induce significant changes in photophysical properties, especially in the short-wave infrared region (1000-2500 nm), suggesting the potential application of 1<sup>+</sup>•TCNQ<sup>•-</sup> as a bifunctional material.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e01449"},"PeriodicalIF":3.7,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Substitution of CH<sub>3</sub> by CH<sub>2</sub>F in 2-Methylerythritol Cyclodiphosphate Triggers Potent Inhibition of IspG with Concomitant Fluoride Ion Expulsion.","authors":"Clea Witjaksono, Vivien Herrscher, Hannah Jobelius, Nathan Noël, Fabien Massicot, Jean-Luc Vasse, Jean-Bernard Behr, Myriam Seemann","doi":"10.1002/chem.202502471","DOIUrl":"https://doi.org/10.1002/chem.202502471","url":null,"abstract":"<p><p>IspG (also known as GcpE) is a key [4Fe-4S] metalloenzyme that catalyzes the penultimate step of the methylerythritol phosphate (MEP) pathway, a well-established target for the development of new antimicrobials. This oxygen-sensitive enzyme mediates the reductive dehydroxylation of 2-C-methyl-d-erythritol 2,4-cyclodiphosphate (MEcPP) to (E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate (HMBPP), requiring electron transfer proteins to deliver two electrons needed for catalysis. To probe the mechanism of IspG and access new mechanism-based inhibitors, we synthesized a substrate analogue, monofluoromethyl-d-erythritol cyclodiphosphate, in which the natural methyl group of MEcPP is replaced by a CH<sub>2</sub>F group. This analogue proved to be a potent inhibitor of IspG. This study also demonstrates that electron capture is a prerequisite for inhibition and that the inhibitor leads to fluoride release in the IspG-catalyzed reaction. Together, these results provide further support for the involvement of a carbanionic intermediate in the IspG mechanism.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e02471"},"PeriodicalIF":3.7,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rebecca K Walde, Trey C Pankratz, Amelia M Wheaton, Milton Acosta, John F Berry
{"title":"Asymmetric Ligand Field Effects in Electron-Rich Heterometallic Extended Metal Atom Chain Compounds.","authors":"Rebecca K Walde, Trey C Pankratz, Amelia M Wheaton, Milton Acosta, John F Berry","doi":"10.1002/chem.202502090","DOIUrl":"https://doi.org/10.1002/chem.202502090","url":null,"abstract":"<p><p>In heterometallic systems, electron donation from the ligands may influence the metal atoms in either a symmetric or asymmetric way, with the expected case being that the more electronegative metal is favored. Here, we describe a systematic study of heterometallic compounds where this expectation is not observed. In this study, we use a modification of the symmetric 2,2'-dipyridylamine (dpa) ligand with electron donating ethyl groups, the 4,4'-diethyl-2,2'-dipyridylamine ligand (dedpa), to prepare heterometallic extended metal atom chain (HEMAC) complexes with formula Mo<sub>2</sub>M'(dedpa)<sub>4</sub>Cl<sub>2</sub> (M' = Cr, Mn, Fe, Co, Ni). The effects of the electron donating substituents were studied through techniques including crystallography, magnetometry, cyclic voltammetry, EPR, Mössbauer, electronic absorption spectroscopy, and DFT calculations. We find that the new HEMACs are indeed more electron rich, easier to oxidize, and, most interestingly, the impact of the ethyl substituents is not applied equally to all the metals in the chain. The ligand field is stronger at the Mo<sub>2</sub> site, but is surprisingly weaker at the M' center when compared to Mo<sub>2</sub>M'(dpa)<sub>4</sub>Cl<sub>2</sub> complexes. We also find that changing the ligand field allows for previously unassigned electronic transitions to become visible, including excitations tentatively assigned to a triplet δ-δ* state within the Mo<sub>2</sub> unit.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e02090"},"PeriodicalIF":3.7,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Photo-enabled α-C(sp<sup>3</sup>)-H Functionalization of Sulfides.","authors":"Peng Cheng, Jie Ding, Zhenda Tan","doi":"10.1002/chem.202502638","DOIUrl":"https://doi.org/10.1002/chem.202502638","url":null,"abstract":"<p><p>Sulfides hold significant value in fine chemicals and pharmaceuticals. Efficient α-C ─ H transformations of these compounds offer streamlined routes to value-added derivatives but pose substantial challenges due to high C ─ H BDEs and catalyst poisoning. Photochemical strategies have emerged as powerful solutions for enabling α-C(sp<sup>3</sup>)-H functionalization of sulfides. This review comprehensively surveys photo-enabled sulfide α-C ─ H functionalization methodologies, with particular focus on hydrogen atom transfer (HAT) and electron transfer/proton transfer (ET/PT) mechanisms.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e02638"},"PeriodicalIF":3.7,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"NIR-II Organic Phototheranostics: Matching Rotatable Donors and Shielding Acceptors for Enhanced Imaging and Phototherapy by Stabilized Triplet Excitons and Optimized Radiative Decay.","authors":"Jianye Gong, Yue Zhang, Jianguo Wang, Guoyu Jiang","doi":"10.1002/chem.202502527","DOIUrl":"https://doi.org/10.1002/chem.202502527","url":null,"abstract":"<p><p>Second near-infrared (NIR-II) organic phototheranostic agents (OPTAs) have received significant interests in cancer treatment by enabling precise positioning of deep-seated lesions and highly efficient ablation of tumors. However, competition between radiative and nonradiative pathways of the excitons sets great obstacles for obtaining robust OPTAs. Herein, we propose to fabricate high-performance NIR-II OPTAs through molecular engineering of acceptor shielding units as well as manipulating molecular conformations by donor rotation. Accordingly, two series of OPTAs (BPN series: 4,4'-(ethene-1,1-diyl)bis(N,N-dimethylaniline) as rotatable donor and butadiene as π-bridge, BPTQ series: julolidine as donor and 2-vinylthiophene as π-bridge) with different acceptor shielding units were designed. Photophysical data and theoretical calculations verified the introduction of rotatable donors can help to realize highly twisted molecular conformations, resulting in enhanced NIR-II emission and photothermal conversion efficiency (PCE). Moreover, the adoption of acceptor shielding units is advantageous for stabilizing triplet excitons for radical reactive oxygen species (ROS) generation. As a result, a balance was achieved for BPN-P nanoparticles (NPs) in the BPN series, which exhibited high NIR-II emission, good radical ROS generation and highest PCE of 63%. BPN-P NPs achieved both high-resolution NIR-II angiography and imaging-guided synergistic photodynamic/photothermal cancer treatment in live mice model, showcasing the effectiveness of the strategy.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e02527"},"PeriodicalIF":3.7,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"π-π Conjugated g-C<sub>16</sub>N<sub>19</sub> Skeleton-Supported Single-Atom Catalyst for Nitrogen Reduction Reaction: A \"Lock and Key\" Coevaluation of Activity and Selectivity Involved in Constant Potential and pH Effect.","authors":"Yali Lu, Zongjin Hu, Qiang Zhang, Chenglong Shi, Qingjun Zhou, Yuling Song","doi":"10.1002/chem.202502611","DOIUrl":"https://doi.org/10.1002/chem.202502611","url":null,"abstract":"<p><p>The efficient development of electrocatalysts for the nitrogen reduction reaction (NRR) under ambient conditions has been greatly challenging due to the high stability of the N≡N bond and the competitive interference from the hydrogen evolution reaction (HER). This work innovatively designs a graphitic carbon nitride substrate (g-C<sub>16</sub>N<sub>19</sub>) with a super-large pore structure based on the self-doping strategy and first-principles calculations, and constructs TM@g-C<sub>16</sub>N<sub>19</sub> (TM = Ti ∼ Au) single-atom catalyst systems. By establishing a \"Four-Step\" screening model, it is found that W@g-C<sub>16</sub>N<sub>19</sub> exhibits the best NRR catalytic performance, with an ultralow limiting potential (U<sub>L</sub>) of -0.23 V. Combining electron structure analyses such as charge density difference, ICOHP value, Bader charge, and spin magnetic moment, the micro-mechanism of W@g-C<sub>16</sub>N<sub>19</sub> effectively activating the σ/π bonds of N<sub>2</sub> molecules through strong d-p orbital hybridization is revealed. Furthermore, based on the pH- and potential-dependent adsorption-free energy results calculated by the constant potential model, pH-potential coupling analysis shows that the configuration has a decisive influence on activity: the E-I/S-V mode dominates in alkaline media, while the E-O/S-O pathway is predominant under acidic conditions. In the E-I configuration, the energy barrier of the rate-determining step (PDS) of NRR decreases with the decrease of the electrode potential; conversely, the energy barrier of the PDS of NRR in the E-O/S-V/S-O configuration increases with the decrease of the electrode potential.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e02611"},"PeriodicalIF":3.7,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Metal-Free [3 + 3] and [4 + 2] Cascade Cyclization of Dihydroisoquinolines and Ene-Yne-Oxazolones: Synthesis of Indenoisoquinolinoquinolinamides.","authors":"Rattana Worayuthakarn, Phum Tachachartvanich, Rapeepat Sangsuwan, Somsak Ruchirawat, Nopporn Thasana","doi":"10.1002/chem.202502380","DOIUrl":"https://doi.org/10.1002/chem.202502380","url":null,"abstract":"<p><p>A cascade cyclization of polycyclic indenoisoquinolinoquinolinamides has been realized via metal-free [3 + 3] and [4 + 2] intramolecular cyclization of ene-yne-oxazolones and dihydroisoquinoline under neutral conditions in good to excellent yield. In this process, three rings and four bonds are formed with high atom economy under reaction conditions that comply with green chemistry principles. The biological activity of the indenoisoquinolinoquinolinamide analogs, which mimic the structure of lamellarins-a group of marine natural products-was evaluated. The results indicated that these indenoisoquinolinoquinolinamide analogs exhibited notable anti-cancer activity, with cytotoxicity profiles comparable to those of their lamellarin counterparts.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e02380"},"PeriodicalIF":3.7,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Toward Non-Isocyanate Polyurethanes: Green Synthesis Routes and Recycling Technologies.","authors":"Xiaohuan Qin, Xin Wang, Zhengbiao Zhang","doi":"10.1002/chem.202502319","DOIUrl":"https://doi.org/10.1002/chem.202502319","url":null,"abstract":"<p><p>Polyurethanes (PUs) are extensively utilized polymers known for their excellent properties. However, the conventional synthesis of PUs heavily depends on toxic isocyanates, creating significant environmental and health risks. To mitigate these issues, research has increasingly focused on synthesizing non-isocyanate polyurethanes (NIPUs). This review systematically discusses the primary green synthesis routes for NIPUs: (1) Bis(dialkyl carbonate) route, (2) Transurethanization route, (3) Cyclic carbonate route, and (4) Ring-opening polymerization (ROP) route. While PUs exhibit superior mechanical and chemical performance, their disposal at the end of life remains a major challenge. Currently, the main recovery methods include chemical degradation (or raw material recycling) and mechanical recycling, with chemical recycling offering potential for a closed-loop process. This review briefly summarizes these disposal strategies, aiming to encourage sustainable practices. It highlights recent advancements in green synthesis and recycling technologies, focusing on pathways for creating environmentally friendly and recyclable NIPUs. In light of increasing environmental and regulatory pressures to minimize the use of isocyanates due to their toxicity, this paper comprehensively reviews current advances and future prospects in the synthesis and recycling of NIPUs, focusing on sustainable and environmentally friendly approaches. The review delves into innovative synthesis methodologies for NIPUs, highlighting green pathways while also addressing challenges related to end-of-life polyurethane management, with a focus on advancements in chemical recycling technologies.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e02319"},"PeriodicalIF":3.7,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"γ-Cyclodextrin-Imidazolium Salt-Based Bioinspired Nanoreactor: Enantioselective Rhodium-Catalyzed Arylation of Unprotected Isatin with Arylboronic Acids.","authors":"Susumu Tsuda, Narumichi Nozawa, Ryoji Ueda, Reo Ikeda, Tatsuo Yajima, Shin-Ichi Fujiwara, Nobuaki Kambe, Yutaka Nishiyama","doi":"10.1002/chem.202502481","DOIUrl":"https://doi.org/10.1002/chem.202502481","url":null,"abstract":"<p><p>The optically active 3-aryl-3-hydroxy-2-oxindole skeleton is a promising pharmacophore in drug design and has led to the development of metal-catalyzed asymmetric reactions using designed chiral ligands for synthesizing 3-aryl-3-hydroxy-2-oxindoles from isatins (2,3-oxindoles), 3-aryl-2-oxindoles, and α-ketoamides. Although the arylation of isatins is vital for convergent synthesis, most studies have used N-protected isatins, requiring the removal of protecting groups to obtain the desired bioactive products. Despite limited success in the direct high-enantioselective arylation of unprotected isatins (NH isatins), such arylation holds significant potential for improving atomic and synthetic efficiencies. In aqueous media, cyclodextrins (CDs) with hydrophobic and chiral cavities can selectively include organic compounds, making them potential nanoreactors for asymmetric reactions. In this study, imidazolium salts bearing a γ-CD were applied as N-heterocyclic carbene (NHC) ligands for the Rh-catalyzed asymmetric arylation of NH isatins in environmentally benign aqueous ethanol. The arylation was successfully achieved in high yield and enantioselectivity using our γ-CD-NHC-Rh catalyst. This suggests that the arylation proceeds in the γ-CD cavity (host) through the self-inclusion of NHC─Rh complex intermediates (guests). These bio-inspired transition metal catalysts based on host-guest linkage systems are expected to contribute significantly to the development of efficient organic synthesis reactions with high enantioselectivity.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e02481"},"PeriodicalIF":3.7,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Helical Polymer-Based Polycarboxylate as Chiral Ligands in Cu-Catalyzed Enantioselective Diels-Alder Reaction in Water.","authors":"Naoaki Kamiya, Takeshi Yamamoto, Michinori Suginome","doi":"10.1002/chem.202502697","DOIUrl":"https://doi.org/10.1002/chem.202502697","url":null,"abstract":"<p><p>Water-soluble poly(quinoxaline-2,3-diyl)s (PQXlac) bearing chiral carboxylic acid side chains derived from l-lactic acid were used for Cu-catalyzed enantioselective Diels-Alder reaction in water. The reaction of azachalcone with cyclopentadiene in the presence of PQXlac (1000mer, 1 mol% monomer unit) and Cu(NO<sub>3</sub>)<sub>2</sub> (1 mol% Cu) proceeded at 5 °C in good yield with high enantioselectivity up to 99% ee. The utilization of the corresponding oligomers shorter than 10mer resulted in low chemical yield with low enantioselectivity, suggesting that a tight helical structure is essential for the formation of an effective catalyst. A comparison of the random and block copolymer of PQXlac and PQXteg, which has achiral tetra(ethylene glycol) side chains, indicated that block copolymer, in which the carboxylate groups are more densely packed, showed higher chemical yields along with higher enantioselectivity. These results suggest that the active catalyst has a copper dicarboxylate structure in which two carboxylate groups on every other monomer unit coordinate to the Cu center to form an effective chiral reaction environment.</p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":" ","pages":"e02697"},"PeriodicalIF":3.7,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145342318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}