bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zwitterionic 2‐Phosphaethene‐thiolates [(LC)P=CS(LC/P)]+ as PCS Building Blocks (LC=NHC, LP=PR3)
Authors: Royla Philipp , Schwedtmann Kai , Gomila Rosa M. , Frontera Antonio , Weigand Jan J. 
Published: November 2024

AbstractThe zwitterionic compounds [(LC)P=CS(LC/P)]+ (3+, LC=NHC, LP=PR3), featuring cationic substituents at the phosphorus and carbon atoms, are synthesized as their triflate salts at a multi‐gram scale from the reaction of Lewis base adducts of CS2, namely LC/P−CS2 (4), with a combination of [(LCP)4][OTf]4 (1[OTf]4) and Ph3P. The feasibility of using 3+ as PCS building blocks is showcased in their reactions with representative electrophiles (MeOTf) and nucleophiles (MesMgBr, Ph3PCH2), leading to selective functionalization of the PCS core at the S‐ and P‐terminus, respectively. Additionally, it is reported that 3+ can function as ambident nucleophiles with AgOTf (2 equivalents), affording unprecedented linear coordination polymer [Ag2(OTf)3‐μ2:κP,κS−((LC)P=CS(PCy3))]+ (6 b), where the PCS moiety acts as a bridging ligand in transition metal complexes for the first time. Reduction of 3+ facilitates the cleavage of the P‐ and C‐bound substituents leading to the formation of the [PCS]− anion. Moreover, cycloaddition reactions of 3+ with 1[OTf]4 are shown to selectively yield five‐ and eight‐membered polyphosphorus heterocycles. Preliminary results suggest the possibility of activating the C−S bond in [(LC)P=CS(LC)]+, resulting in the formation of [(LC)P=C(LC)−P(LC)][OTf]2, 12[OTf]2, which may serve as a synthon for the PCP unit in future studies.
One‐Pot Cobalt‐ or Copper‐Catalyzed Asymmetric Ring‐Opening Hydrosilylation/Hydroboration of Arylidenecyclopropanes
Authors: Tan Boon Beng , Ge Shaozhong 
Published: November 2024

AbstractAn operationally convenient cobalt‐catalyzed one‐pot one‐step hydrosilylation/hydroboration reaction of arylidenecyclopropanes is developed to access racemic 1,4‐borylsilylalkanes. In addition, the corresponding asymmetric reaction is developed with a chiral copper catalyst to prepare 1,4‐borylsilylalkanes with high enantioselectivity by a one‐pot two‐step procedure. Mechanistic studies reveal that this difunctionalization process begins with metal‐hydride‐catalyzed ring‐opening hydrosilylation of arylidenecyclopropanes to generate homoallylsilane intermediates, followed by regio‐ or enantioselective metal‐hydride‐catalyzed hydroboration of homoallylsilanes to produce skipped borylsilylalkanes. Selective transformations of C−B and Si−H bonds in skipped borylsilylalkane products are also demonstrated.
Formal nullwertige Bis(aren)Germylenkomplexe von Zirconium und Hafnium
Authors: Eberhardt Max J. , Baum Mira , Clewing Stefan F. , Schubert Hartmut , Wesemann Lars 
Published: November 2024

AbstractZirconium‐ und Hafniumtetrachlorid bilden mit einem intramolekularen Germylen‐Phosphor‐Lewis‐Paar Addukte (2, 3). Durch eine Zweielektronenreduktion mittels [MesNacnacMg]2 werden zweiwertige Komplexe mit einer η6‐Trip‐Koordination am Zr(II)‐ und Hf(II)‐Metallatom erhalten (4, 5). Die weitere Reduktion dieser M(II)‐Komplexe führt zu nullwertigen Komplexen von Zirconium (6) und Hafnium (7), welche strukturell charakterisiert wurden. Zwei Areneinheiten und das Germylen koordinieren am Metall. Für beide Derivate 6 und 7 wurde für die koordinierende P‐Phenyleinheit eine gefaltete Konformation festgestellt. Die nullwertigen Komplexe können auch durch die Vierelektronenreduktion eines Reaktionsgemisches der Metalltetrachloride mit dem Germylen‐Phosphor‐Lewis‐Paar in guten Ausbeuten erhalten werden. Durch die Reaktion der nullwertigen Verbindungen mit Kohlenstoffmonoxid wurden Carbonylkomplexe synthetisiert. Dimethylbutadien zeigt eine Reaktion mit einer der koordinierten Areneinheiten und dem Germylenliganden der nullwertigen Komplexe, wodurch ein Cyclohexadienyl‐ und ein Triorganogermatligand gebildet werden. Im Falle des Zirconiums ist diese Reaktion reversibel.
Iodide Anion Enables a Reductive Cross‐Electrophile Coupling for Preparing Tertiary Amines
Authors: Lemmerer Miran , Tona Veronica , Just David , Vavrík Miloš , Maryasin Boris , Di Mauro Giovanni , zur Bonsen Andreas B. , Kaiser Daniel , Maulide Nuno 
Published: November 2024

AbstractThe reducing power of iodide anion is an underexplored property that can be used for the cross‐electrophile coupling of organic molecules. Herein we harness this trait for the preparation of tertiary amines through the combination of two simple reagents: an electrophilic‐carbon precursor and an iminium iodide in a dual role – both as nitrogen‐containing building block and as reducing agent. The underlying mechanism of this new C−C bond‐formation paradigm is explored through a combination of experiment and quantum chemical calculations.
Coordination Induced Spin State Transition Switches the Reactivity of Nickel (II) Porphyrin in Hydrogen Evolution Reaction
Authors: Xue Hao‐Zong , Wu Jia‐Hui , Wang Bing‐Wu , Gao Song , Zhang Jun‐Long 
Published: November 2024

AbstractElectron spin plays a critical role in chemical processes, particularly in reactions involving metal complexes with unpaired electrons. However, more definitive state‐to‐state experiments are needed to better elucidate the role of electronic spin. Herein, we chose nickel (II) 5,10,15,20‐tetrakis(pentafluorophenyl) porphyrin 1 as a catalyst, which allows switching from a low spin to a high spin state of Ni (II) center through an axial pyridine coordination, for electrocatalytic hydrogen evolution reaction (HER). When pyridine is present, we observed β‐hydrogenation of porphyrin through electron transfer followed by proton transfer. In contrast, hydrogen evolution mainly occurs via the concerted proton‐coupling electron transfer without pyridine coordination. Similar distinct spin‐dependent selectivity was also observed in chemical reduction of 1 by CoCp2 with subsequent addition of pyridinium p‐toluenesulfonate. Computational calculations using density functional theory demonstrated that the transition from low spin to high spin state enriches the ligand's electron density after one‐electron reduction, leading to preferential protonation of β‐periphery rather than meso‐position or metal center.
Methanolation of Olefins: Low‐Pressure Synthesis of Alcohols by the Formal Addition of Methanol to Olefins
Authors: Stahl Sebastian , Vossen Jeroen T. , Popp Stephan , Leitner Walter , Vorholt Andreas J. 
Published: November 2024

AbstractMethanolation of olefins is introduced as a new low‐pressure synthetic pathway to C1 elongated alcohols. Formally, H3COH is added to the C=C bond in a 100 % atom efficient manner. Mechanistically, the overall transformation occurs as a tandem reaction sequence by combining the dehydrogenation of methanol to syngas at a CO : H2 ratio of 1 : 2 with subsequent hydroformylation to the corresponding aldehyde and its final hydrogenation to the alcohol. The dehydrogenation and hydrogenation steps are catalyzed by a Mn/pincer complex, while the hydroformylation is accomplished by a Rh/phosphine catalyst. Using 1‐octene as prototypical substrate, a yield of 80 % nonanol was achieved with a ratio of 93 : 7 of linear to branched alcohols and turnover numbers (TONRh) of more than 17 000 could be obtained in relation to the precious metal Rhodium. The integrated catalytic system provides direct access to alcohols from olefins and “green” methanol, avoiding the handling of pressurized CO and H2 and the use of specialized high‐pressure equipment as the process conditions do not exceed 10 bar with partial pressures of syngas in the range of only 1–2 bar.
Enhanced Photocatalytic Synthesis of Urea from co‐Reduction of N2 and CO2 on Z‐Schematic SrTiO3‐FeS‐CoWO4 Heterostructure
Authors: Ahmad Muhammad Irfan , Liu Yanming , Wang Yaqi , Cao Peike , Yu Hongtao , Li Houfen , Chen Shuo , Quan Xie 
Published: November 2024

AbstractThe photocatalytic co‐reduction of CO2 and N2 is a sustainable method for urea synthesis under mild conditions. However, high‐yield synthesis of urea is a challenge due to the sluggish kinetics of the C−N coupling reaction. Herein, we have successfully engineered a Z‐scheme photocatalyst, SrTiO3‐FeS‐CoWO4, for boosting photocatalytic urea synthesis via enhancing the initial CO2 and N2 adsorption step and reducing the energy barrier for the C−N coupling reaction. A high urea yield of 8054.2 μg ⋅ gcat−1 ⋅ h−1 was achieved on SrTiO3‐FeS‐CoWO4, which was significantly higher than the state‐of‐the‐art. The SrTiO3‐FeS‐CoWO4 Z‐scheme photocatalyst, with accelerated charge transfer by FeS, not only had dual active sites for the chemical adsorption and activation of CO2 and N2, but also retained the high conduction band (−1.50 eV) and accelerated supply of electrons and protons, which are responsible for its good photoreduction activity and significantly reduced energy barrier for the rate‐determining step of C−N coupling reaction.
Electron Transfer Mediator Modulates Type II Porphyrin‐Based Metal–Organic Framework Photosensitizers for Type I Photodynamic Therapy
Authors: Zhuang Jiahao , Liu Shitai , Li Bowen , Li Zhiyao , Wu Chongzhi , Xu Duo , Pan Weidong , Li Zhen , Liu Xiaogang , Liu Bin 
Published: November 2024

AbstractPhotodynamic therapy (PDT), a minimally invasive and effective local treatment, heavily depends on photosensitizer (PS) performance and oxygen availability. Despite the use of PS‐based metal–organic frameworks (MOFs) to address the solubility and aggregation issues of PSs, the inherent hypoxic intolerance of mainstream Type II PDT remains challenging. Herein, we report an electron transfer strategy for the fabrication of hypoxia‐tolerant Type I MOFs by encapsulating thymoquinone (TQ) into existing Type II MOFs. With TQ serving as an effective electron transfer mediator, it facilitates the electron transfer process from the MOF ligand PS to oxygen, establishing the Type I pathway and attenuating the original Type II pathway. Four representative porphyrin‐based MOFs are synthesized to demonstrate the proposed strategy. Our findings reveal that TQ@MOF‐1 nanoparticles (NPs) exhibit enhanced anticancer activity under hypoxic conditions and superior in vivo antitumor efficacy compared to parent MOF‐1 NPs. This work offers an effective and universal strategy to modulate ROS generation in PS‐based MOFs, endowing hypoxic tolerance with improved PDT performance against solid tumors.
Metal‐Organic Framework‐Based Electrodes for Asymmetric Supercapacitors
Authors: Zhang Liuliu , Wang Yisong , Yang Cui , Tao Kai 
Published: November 2024

AbstractSupercapacitors (SCs) are a promising electrochemical device in the field of electrochemical energy storage, but their wide range applications are limited by relatively low energy density. Asymmetric supercapacitors (ASCs) based on different positive and negative electrodes offer the possibility to increase the energy density by extending the voltage window. It is essential to explore novel electrode materials to boost the electrochemical properties of ASCs. Metal‐organic frameworks (MOFs) have emerged as ideal electrode materials for SCs, due to their high porosity, tunable structure and highly dispersed active sites. MOFs can also be used as templates or precursors for the preparation of versatile electrode materials, such as carbon materials and metal compounds. In this minireview, SCs and MOF‐based electrode materials are first introduced, followed by an overview of recent advances in the synthesis of MOF‐based electrode materials including pristine MOFs, MOF derivatives and their composites, and their applications in ASCs acted as negative electrode, positive electrode or both. Finally, the challenges and prospects of MOF‐based ASCs are discussed.
Fluorine‐Free Bis(glycolato)borate Anion‐Based Salts and Electrolytes: Structures, Properties, and Lithium Compatibility
Authors: Xu Yanqi , Filippov Andrei , Shimpi Manishkumar R. , Ullah Shah Faiz , Johansson Patrik 
Published: November 2024

AbstractA number of bis(glycolato)borate (BGB) anion‐based salts, comprising Li+, Na+, K+, Mg2+ and Ca2+ cations, has been synthesized and characterized. Fluorine‐free electrolytes based on LiBGB and organic solvents, such as dimethyl sulfoxide (DMSO), triethyl phosphate (TEP), and trimethyl phosphate (TMP) have been created and their transport properties, thermal and electrochemical stabilities, and lithium compatibility are examined. The ionic conductivities of the 1 M LiBGB‐TEP and 1 M LiBGB‐TMP electrolytes are ca. 2–3 times lower than for the 1 M LiBGB‐DMSO electrolytes (2.05, 2.65 vs. 5.70 mS cm−1 at 25 °C), and as compared to the state‐of‐the‐art 1 M lithium hexafluorophosphate (LiPF6) in EC:DEC (EC:DEC=1 : 1 in vol., LP40) they display lower ionic conductivities, but the formers’ redox stability on aluminum (Al) and glassy carbon electrodes are much better. Concentrated (>1 M) LiBGB‐DMSO electrolytes display enhanced redox stability, but worse Al passivation. Among the electrolytes, 1 M LiBGB‐TMP achieves the best long‐term stability over 300 h at 0.1 mA/cm2 for Li plating‐stripping while the Li compatibility needs to be further improved. Overall, this study introduces a family of versatile fluorine‐free orthoborate salts and electrolytes for mono‐ and divalent batteries, and a fundamental understanding of their transport and electrochemical properties, aiming towards battery applications.
Insights into the Mechanism of a Vanadium Bromoperoxidase from the Marine Macro‐Algae Corallina pilulifera for Biocatalytic Halogenation
Authors: Mitchell Daniel E. , Garcia‐Rodriguez Esther , Isupov Michail N. , Littlechild Jennifer A. 
Published: November 2024

AbstractVanadium haloperoxidases have been studied to understand their mechanism and halide specificity. Crystal structures of vanadium bromoperoxidase enzyme complexes from Corallina piluifera, with vanadate and bromide and with phosphate and chloride, show significant displacement of loop residues 336–338 upon halogen binding. This shows a “closed position” of Leu337 locking the bromide ion in a hydrophobic environment favoring the vanadium peroxide reaction with the halogen by retaining the resulting hypobromite in the enzyme active site. The bound cofactor exists as a mixture of free vanadate and histidine553‐vanadate adduct. A mutant enzyme Arg397Trp also has been crystallized with bound phosphate and its structure determined with and without the bound bromide ion. The precise positions of the bromine have been determined using its anomalous signal. The bromide binding site in the mutant enzyme is displaced by 2.5 Å resulting in a mixed population of the “open” and the “closed” forms of Leu337. This allows additional chloroperoxidase activity due to re‐positioning of the halogen ion 0.6 Å closer to the vanadate ion. These studies support the application of vanadium haloperoxidase enzymes for selective halogenation of important drug molecules.
Allylation, Alkenylation, and Alkynylation of Monofluoromethyl Ketyl Radical Enabled by Photoredox Halogen‐Atom‐Transfer
Authors: Sun Meng‐Qi , Zhai Shi‐Jing , Nie Jing , Cheng Ying , Deng Xiaojuan , Ding Guosheng , Cahard Dominique , Ma Jun‐An , Zhang Fa‐Guang 
Published: November 2024

AbstractIn this study, we disclose an innovative strategy to access α‐monofluoromethyl secondary alcohol derivatives under mild blue‐light irradiation from brominated fluoroethanol benzoate (BFEB). This reaction takes advantages of bulky silicon radical as a halogen atom transfer (XAT) acceptor to generate the nucleophilic monofluoromethyl ketyl‐type radical, which serves as the key intermediate to couple with a series of phenylsulfonyl‐masked substrates. A broad scope of allyl, alkenyl (Z and E configurations), and alkynyl α‐monofluoromethyl carbinol derivatives were obtained in moderate to good yields.
Experimental and model‐based investigation of the droplet size distribution during the mixing process in a batch‐settling cell
Authors: Sibirtsev Stepan , Thiel Lukas , Zhai Song , Cai Yutang Toni , Recke Louis , Jupke Andreas 
Published: November 2024

AbstractThe design of a liquid–liquid gravity settler relies on the experimental investigation and model‐based description of the phase separation process in a batch‐settling cell. However, according to the current state of the art, the modelling assumes a monodisperse droplet size distribution (DSD), which can lead to an inaccurate settler design. This study considers the polydispersity of the initial DSD resulting from the mixing process in the settling cell to enhance the model accuracy. DSDs of o/w and w/o dispersions during the mixing process in a settling cell are investigated in this work for 2‐methyltetrahydrofuran/water and decane/water material systems at hold‐ups of 25–50 vol.% and stirrer speeds of 400–850 min−1. Sauter mean diameters (SMD) and DSD shapes are analyzed to identify the influence of the investigated parameters on the SMD and DSD and to model the SMD and DSD. The experimental investigation shows that stirrer speed, hold‐up, and interfacial tension significantly affect the DSD, while the viscosity of the continuous phase plays a minor role. The SMD is correlated to the Weber number, viscosity group, and hold‐up by a model with a mean absolute percentage error (MAPE) of 3.6%. The DSD is described by a log‐normal distribution function with a MAPE of 5%. The SMD and DSD models presented in this work can be used to describe the initial DSD of the phase separation process in a batch‐settling cell, considering polydispersity and thus increasing the modelling accuracy of the phase separation process.
Association Between Orthostatic Hypotension With Coronary Slow Flow in Patients With Chest Pain: A Single Center Experience
Authors: Han Lijun , Li Meng , Xie Wenting , Lu Jianran , Yu Liang , Liu Xinying , Lv Na , Zhang Lulu , Zhang Yan , Liu Yanan , Li Yanrong 
Published: November 2024

ABSTRACTBackgroundOrthostatic hypotension (OH) is associated with different cardiovascular diseases, however, the association between OH and coronary slow flow (CSF) has never been evaluated before.Materials and MethodsChest pain patients who underwent coronary angiography (CAG) and with normal coronary arteries in our department from January 1st, 2022 to August 31st, 2023 were retrospectively enrolled. Patients were divided into the CSF group and the normal blood flow (NBF) group. Relative clinical information, laboratory test results as well as the results of CAG were collected and analyzed. Both uni‐variable and multi‐variable logistic regression analyses were used to evaluate the association between OH and CSF in these patients.ResultsFour thousand six hundred and twenty‐seven patients underwent CAG and 655 patients had normal coronary arteries. In which, sixty‐nine patients were diagnosed with CSF while 586 patients were diagnosed with NBF. Uni‐variable analysis revealed that higher body weight index, faster heart rate in sitting position, accompanied with chronic kidney disease, did not take Antidiabetic therapy, higher level of aspartate transaminase, uric acid, triglyceride, total cholesterol, ApoB1, low‐density lipoprotein cholesterol, homocysteine, B‐type natriuretic peptide as well as OH are the risk factors for CSF in these patients. Multi‐variable logistic regressing analysis further demonstrated that OH was the independent risk factor for predicting CSF in these patients.ConclusionsOur finding suggests OH might be a useful predictor for CSF in patients with chest pain but normal coronary arteries.
Sustainable Bio‐Adsorbents From Banana Post‐Harvest Agricultural Residues: Kinetics, Equilibrium, and Mechanism Prospection of Methylene Blue Dye Adsorption
Authors: Milani Laura Alessandra Prado , Zanette Ana Carolini Córneo , Dauzacher Natalí Bianca Rafael Olária , Crippa Denis Depieri , Possenti Graziele Vefago Boaventura , Battisti Rodrigo 
Published: November 2024

ABSTRACTWater pollution from industrial‐colored effluents, generated by large volumes of liquid effluents containing synthetic dyes, generally harmful and non‐biodegradable, affects environmental biota and human health. Considering the potential use as bio‐adsorbents of agro‐industrial residues, in the present work insights into the kinetics, equilibrium, and mechanism of the methylene blue (MB) dye adsorption by six bio‐adsorbents produced from the post‐harvest residues from the banana tree, a widely cultivated crop in Brazil, were investigated. The six prepared bio‐adsorbents were tested to verify the adsorption capacity as gross residues, after carbonization, and after alkaline‐chemical activation. Bench‐scale experiments conducted at different conditions showed that experimental data were better described by the Langmuir isotherm, by the intraparticle diffusion model (with external diffusion being the dominant step), followed by the pseudo‐second‐order model, indicating the predominance of monolayer chemisorption. In addition, maximum adsorption capacities ranged between 10.55 and 25.51 mg/g, with a higher dye removal rate at alkaline pH. The adsorption of the MB dye onto the six produced bio‐adsorbents occurred through both polar and nonpolar interactions. The overall study indicated that both the pseudo‐stem and the leaves from post‐harvest banana crops could be a cost‐effective natural bioresource for producing efficient and sustainable bio‐adsorbents for treating colored liquid effluents.
Nature‐inspired Novel Quaternary Ammonium Compounds: Synthesis, Antibacterial and Antibiofilm Activity
Authors: Muzychka Liubov , Hodyna Diana , Metelytsia Larysa , Smolii Oleg 
Published: November 2024

AbstractInspired by marine compounds isolated from sponges and the increased need for new effective antimicrobials, novel quaternary ammonium compounds with long alkyl chains (C8‐C12) were designed and synthesized. Antibacterial and antibiofilm activity of new compounds was evaluated against six microbial strains (S. aureus, E. coli, and P. aeruginosa). All synthesized ammonium salts displayed antibacterial activity with MIC values ranging from 5.0 to 25.0 μg/mL. In addition, most compounds showed strong inhibition of biofilm formation of S. aureus ATCC 25923, P. aeruginosa PA01, and colistin‐resistant P. aeruginosa (CRPA) at a concentration of 5.0 μg/mL. Ammonium salt 3 showed 100 % inhibitory activity against all tested bacterial biofilms except that of colistin‐resistant S. aureus (CRSA).