bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quinoxaline‐Based D–A Copolymers for the Applications as Polymer Donor and Hole Transport Material in Polymer/Perovskite Solar Cells
Authors: Sun Chenkai , Zhu Can , Meng Lei , Li Yongfang 
Published: October 2021

AbstractPolymer solar cells (PSCs) have achieved great progress recently, benefiting from the rapid development of narrow bandgap small molecule acceptors and wide bandgap conjugated polymer donors. Among the polymer donors, the D–A copolymers with quinoxaline (Qx) as A‐unit have received increasing attention since the report of the low‐cost and high‐performance D–A copolymer donor based on thiophene D‐unit and difluoro‐quinoxalline A‐unit in 2018. In addition, the weak electron‐deficient characteristic and the multiple substitution positions of the Qx unit make it an ideal A‐unit in constructing the wide bandgap polymer donors with different functional substitutions. In this review article, recent developments of the Qx‐based D–A copolymer donors, including synthetic method of the Qx unit, backbone modulation, side chain optimization, and functional substitution of the Qx‐based D–A copolymers, are summarized and discussed. Furthermore, the application of the Qx‐based D–A copolymers as hole transport material in perovskite solar cells (pero‐SCs) is also introduced. The focus mainly on the molecular design strategies and structure–properties relationship of the Qx‐based D–A copolymers, aiming to provide a guideline for developing high‐performance Qx‐based D–A copolymers for the applications as donor in PSCs and as hole transport material in pero‐SCs.
A Bioinspired Adhesive‐Integrated‐Agent Strategy for Constructing Robust Gas‐Sensing Arrays
Authors: Wang Zhao , Jiang Xiangyu , Huang Kang , Ning Lu , Zhang Jianqi , Zhang Feilong , Yang Jiangong , Wu Yuchen , Chen Xiaodong , Yi Yuanping , Shi Xinghua , Chen Yong , Wang Shutao 
Published: October 2021

AbstractGas sensors based on organic molecules are attractive for their tailored molecular structures and controllable functions, but weak interfacial adhesion between sensing materials and supporting substrates has severely hampered their practical applications, particularly in harsh environments. Here, inspired by the combined anchoring‐recognizing feature of natural olfactory systems, an adhesive‐integrated‐agent strategy to integrate the adhesive unit (poly(dimethylsiloxane)) with the sensing unit (organoplatinum(II)) into one chemistry entity, creating robust and sensitive nanobelt array gas sensors is demonstrated. Systematic theoretical and experimental studies reveal that incorporating adhesive units significantly enhances the interfacial adhesion of the array sensors and gas‐bridged super‐exchange electronic couplings of sensing units ensure their efficient gas‐sensing performance. The high shear strength of ≈7.05 × 106 N m−2 allows these arrays to resist aggressive ultrasonication, tape peeling, or repeated bending without compromising their sensing performance. This molecular engineering strategy opens a new guideline to develop robust gas sensors.
Construction of a Clock Catalytic System: Highly Efficient and Self‐Indicating Synthesis of Benzoheterocycles at Ambient Temperature
Authors: Xiong Wu‐Lin , Peng Xiao‐Chong , Zhong Ren‐Yuan , Zheng Jianwei , Duo Shuwang , Gong Shan‐Shan , Sun Hong‐bin , Sun Qi 
Published: October 2021

AbstractInspired by the mechanism of the clock reaction, we rationally constructed a novel phosphomolybdenum blue (PMB) clock catalytic system for a highly efficient synthesis of benzimidazoles and benzothiazoles simply at ambient temperature. The current PMB clock catalytic system exhibits a sharp decoloration event to announce the depletion of the intermediateconstraint, making this synthetic approach self‐indicating and TLC‐free.31P NMR and XPS analysis of PMBcatalyst showed that only two Mo6+ atoms are reduced to Mo5+ atoms in the Keggin structure due to the moderate reducibility of benzimidazoline and benzothiazoline intermediates. Thus,the active Keggin‐type POM cluster could be well maintained in DMSO during the redox cycling of phosphomolybdic acid (PMA) and PMB. 1H NMR tracing experiment not only confirmed the proposed reaction mechanism but also showed that PMB exerts Lewis acid catalytic activityat the early phase of the reaction other than the expected redox catalytic activity.
Transition Metal‐Mediated Functionalization of Isoxazoles: A Review
Authors: Madhavan Suchithra , Keshri Santosh Kumar , Kapur Manmohan 
Published: October 2021

AbstractIsoxazoles are an important class of heterocycles with nitrogen and oxygen in a 1,2‐relationship. They find wide applications in synthetic organic chemistry and are part of several drug molecules. Since the last two decades, great progress has been achieved in the synthesis and functionalization of isoxazoles, in which transition metal catalysis played a pivotal role towards achieving this goal. In particular, the transition metal (TM)‐mediated site‐selective functionalizations of isoxazoles which retain the pharmacologically and synthetically valuable isoxazole skeleton, are highly appealing. This comprehensive review is solely dedicated to the TM‐mediated functionalization of isoxazoles, wherein we have included isoxazoles as directing groups (DG) for TM‐catalyzed C−H functionalization reactions, TM‐catalyzed direct C−H functionalization, along with cross‐coupling reactions of isoxazoles, TM‐catalyzed annulation reactions of isoxazoles and finally ring‐opening reactions of isoxazoles under TM‐catalysis are also discussed. Also, incorporated are discussions on reaction designs, their advantages and limitations, mechanistic details and challenges that need to be addressed to inspire synthetic organic and medicinal chemists to explore new reaction arenas and make use of this key scaffold.
Layer‐by‐Layer Growth of Preferred‐Oriented MOF Thin Film on Nanowire Array for High‐Performance Chemiresistive Sensing
Authors: Lin Yuan , Li Wen‐Hua , Wen Yingyi , Wang Guan‐E , Ye Xiao‐Liang , Xu Gang 
Published: October 2021

AbstractHigh‐quality MOF thin films with high orientation and controlled thickness are extremely desired for applications. However, they have been only successfully fabricated on flat substrates. Those MOF 2D thin films are limited by low exposed area and slow mass transport. To overcome these issues, MOF 3D thin films with good crystallinity, preferred orientation, and precisely controllable thickness in nanoscale were successfully prepared in a controllable layer‐by‐layer manner on nanowire array substrate for the first time. The as‐prepared Cu‐HHTP 3D thin film is superior to corresponding 2D thin films and showed one of the highest sensitivity, lowest LOD, and fastest response among all reported chemiresistive NH3 sensing materials at RT. This work provides a feasible approach to grow preferred‐oriented 3D MOF thin film, offering new perspectives for constructing MOF‐based heterostructures for advanced applications.
Optimierte Synthese von in Lösung verarbeitbarem kristallinem Poly(triazinimid) mit minimalen Defekten für OLED‐Anwendungen
Authors: Burmeister David , Tran Ha Anh , Müller Johannes , Guerrini Michele , Cocchi Caterina , Plaickner Julian , Kochovski Zdravko , List‐Kratochvil Emil J. W. , Bojdys Michael J. 
Published: October 2021

AbstractPoly(triazinimid) (PTI) ist ein hochkristalliner organischer Halbleiter. Obwohl es keine Techniken gibt, die die Synthese makroskopischer Monolagen von PTI ermöglichen, ist es möglich, das kristalline Pulver in Dünnfilme zu verarbeiten und über die Eigenschaften des polykristallinen Materials zu lernen. Wir fanden, dass das Nebenprodukt der herkömmlichen PTI‐Synthese eine kohlenstoffreiche C‐C‐Phase ist, die für den Ladungstransport und die Photolumineszenz von Nachteil ist. Eine optimierte Synthese führt zu einem PTI‐Material mit erhöhter Quantenausbeute, Photostrom und Elektrolumineszenz. Die Protonierung der PTI‐Struktur erfolgt bevorzugt an den Pyridin‐N‐Atomen der Triazin‐Ringe und geht womöglich mit einer Exfolierung der PTI‐Schichten einher, was sich durch die Erhöhung der Quantenausbeute und der Exzitonenlebensdauer zeigt. Struktur‐Eigenschafts‐Beziehungen in PTI werden beschrieben, die die Art der Defekte, ihre Bildung und ihre Vermeidung mit der optischen und elektronischen Leistung von PTI verbinden. Auf der Grundlage unserer Erkenntnisse präparieren wir eine OLED mit PTI als aktivem, metallfreiem Material.
Anatomy of the digestive system of lumpfish (Cyclopterus lumpus) as an adaptation to puffing behavior
Authors: Zhukova Kristina , Stroganov Andrey Nikolaevich 
Published: October 2021

AbstractThe first description of the histology of the digestive tract of the lumpfish Cyclopterus lumpus showed an adaptation for collecting and storing water. The morphology of this species' tract is mostly typical of carnivorous fishes, having a sac‐like stomach for storage and a relatively short intestine of approximately 1.2× the standard body length. The esophagus is relatively short (0.13× standard body length) and thick‐walled; it has a thick muscular coat, and its thickness changes from 0.4 to 1 mm during contraction. The stomach has well‐developed gastric glands and is divided into the histologically distinguishable cardiac, fundus, and pyloric parts. The intestine has the same structure throughout its entire length. The water‐holding ability of lumpfish is provided by well‐developed muscles in the esophagus and stomach distensibility, which differs morphologically from the method used by Tetradontidae and Diodontidae species, who store water in the caudal part of the esophagus. The morphology of the digestive tract proved that this species is an intermediate between Tetradontidae and Diodontidae, which could inflate their bodies by swallowing certain amounts of water, and other fishes which are not able to do so. Results of the work extend current knowledge on the morphological capability of the digestive system of teleost fish, providing water‐blowing behavior.
Synthesis of 4‐dimethylaminobenzyl chrysin ester‐Zn fluorescent chemical sensor for the determination of Cr(VI) in water
Authors: Zhao Haonan , Zhang Junfeng , Lin Xiaolian , Li Huihui , Pan Qinhe 
Published: October 2021

AbstractCr(VI) is a type of dangerous effluent that has caused great harm to human health and the environment. Recognition and perception of Cr(VI) by artificial receptors has attracted extensive attention. A novel fluorescent chemical sensor based on the 5,7‐dihydroxyflavone skeleton was designed and synthesized for the selective recognition of Cr(VI). As confirmed by fluorescence technology, the fluorescent probe 4‐dimethylaminobenzyl chrysin ester–Zn (DBC–Zn) showed high sensitivity and selectivity for dichromate and a fast response (less than 30 sec) recognition. The fluorescence intensity of DBC–Zn varies linearly with the concentration of Cr(VI) in the range 0.1–1 μM. The detection limit of Cr2O72− by DBC–Zn is 2.3 nM, which is far lower than the national safe drinking water standard stipulated by the US Environmental Protection Agency (1.9 μM). The quenching mechanism of the probe can be attributed to the interaction of the dynamic quenching effect and the fluorescence internal filtration effect. In addition, the probe has good stability in both neutral and alkaline environments, and the accuracy of quantitative analysis of Cr2O72− in lake water or tap water is more than 80%. The test paper based on DBC–Zn can effectively detect Cr2O72− at the concentration of 100 ppb. This shows that the probe has a certain practical application value.
Coupling picodroplet microfluidics with plate imaging for the rapid creation of biomanufacturing suitable cell lines with high probability and improved multi‐step assurance of monoclonality
Authors: Pybus Leon P. , Kalsi Devika , Matthews Joe T. , Hawke Ellie , Barber Nicholas , Richer Rachel , Young Alison , Saunders Fay L. 
Published: October 2021

AbstractBackgroundThere is an expectation from regulatory agencies that cell lines used in the commercial production of biopharmaceuticals are derived from a single cell progenitor. Traditional methods of single cell cloning include the use of the limiting dilution cloning method which often requires multiple rounds of low cell density cell plating and either microscopic evaluation that wells contain single cells and/or the calculation of a statistically derived probability of monoclonality.Methods and ResultsWe have combined the single cell screening, deposition and picodroplet imaging ability of Sphere Fluidics’ Cyto‐Mine technology with the plate imaging capability of the Solentim Cell Metric to create a novel workflow for the generation of high producing clonal cell lines with both high probability and assurance of monoclonality. The efficiency of three key stages of the process (single cell picodroplet encapsulation, single picodroplet dispensation and single cell settling in the focal plane of the plate imager) was determined and a probability calculation was derived using the Wilson Score Interval method. The combined probability that a single cell is encapsulated into a picodroplet, is deposited into the correct well of a 96‐well plate and that a cell settles into the focal plane of the plate imager yields a combined > 99% probability of monoclonality. Furthermore, visual verification of a single cell progenitor is obtained at multiple steps throughout the cloning workflow.ConclusionThis novel methodology for the rapid creation of high quality clonal cell lines for biomanufacturing purposes has many advantages over more traditional approaches including improved assurance of single cell derivation, integrated imaging capability, assay flexibility, equipment utilization time and in‐process cell line segregation.
Engineering Escherichia coli for anaerobic alkane activation: Biosynthesis of (1‐methylalkyl)succinates
Authors: Wang Yixi , Nguyen Nam , Lee Seung H. , Wang Qinxuan , May Jeremy A. , Gonzalez Ramon , Cirino Patrick C. 
Published: October 2021

AbstractIn anoxic environments, microbial activation of alkanes for subsequent metabolism occurs most commonly through the addition of fumarate to a subterminal carbon, producing an alkylsuccinate. Alkylsuccinate synthases are complex, multi‐subunit enzymes that utilize a catalytic glycyl radical and require a partner, activating enzyme for hydrogen abstraction. While many genes encoding putative alkylsuccinate synthases have been identified, primarily from nitrate‐ and sulfate‐reducing bacteria, few have been characterized and none have been reported to be functionally expressed in a heterologous host. Here, we describe the functional expression of the (1‐methylalkyl)succinate synthase (Mas) system from Azoarcus sp. strain HxN1 in recombinant Escherichia coli. Mass spectrometry confirms anaerobic biosynthesis of the expected products of fumarate addition to hexane, butane, and propane. Maximum production of (1‐methylpentyl)succinate is observed when masC, masD, masE, masB, and masG are all present on the expression plasmid; omitting masC reduces production by 66% while omitting any other gene eliminates production. Meanwhile, deleting iscR (encoding the repressor of the E. coli iron–sulfur cluster operon) improves product titer, as does performing the biotransformation at reduced temperature (18°C), both suggesting alkylsuccinate biosynthesis is largely limited by functional expression of this enzyme system.
A Cost‐Effective Iron Based Covalent Organic Framework and Its Composite Electrocatalyst for Active and Stable Oxygen Reduction Reaction in Alkaline Solution
Authors: Liu Muye , Wen Yue , Lu Luhua , Kang Qi , Xie Zhicheng , Chen Ying , Tian Xiaocong , Jin Hongyun , Liu Jinghai 
Published: October 2021

AbstractEarth‐abundant non‐precious‐metal‐based materials are promising candidates for low‐cost oxygen reduction reaction (ORR) catalysts. Within those elements, iron is the cheapest given the abundant resources. However, there are few iron‐based ORR catalysts given the difficulty of achieving good electrocatalytic activity and stability with them in comparison to cobalt‐ and nickel‐based catalysts. Moreover, the synthesis of iron‐based ORR catalysts is energy intense and normally requires complicated processes. This work reports an iron‐based covalent organic framework (COF) synthesized through a one‐step low‐temperature solid reaction, which is cost effective and energy saving. The iron‐based COF, named IPPc, shows a high four‐electron‐transfer reaction selectivity. After compositing it with reduced graphene oxide, the resulting composite preserves the high electron‐transfer reaction selectivity and displays a largely enhanced activity and stability.
Temperature‐Controlled Electrospray Ionization: Recent Progress and Applications
Authors: Alexander Harrison Julian , Pruška Adam , Oganesyan Irina , Bittner Philipp , Zenobi Renato 
Published: October 2021

AbstractNative electrospray ionization (ESI) and nanoelectrospray ionization (nESI) allow researchers to analyze intact biomolecules and their complexes by mass spectrometry (MS). The data acquired using these soft ionization techniques provide a snapshot of a given biomolecules structure in solution. Over the last thirty years, several nESI and ESI sources capable of controlling spray solution temperature have been developed. These sources can be used to elucidate the thermodynamics of a given analyte, as well as provide structural information that cannot be readily obtained by other, more commonly used techniques. This review highlights how the field of temperature‐controlled mass spectrometry has developed.
On the Hydrogen Oxalate Binding Motifs onto Dinuclear Cu and Ag Metal Phosphine Complexes
Authors: Kwasigroch Björn , Khuu Thien , Perez Evan H. , Denton Joanna K. , Schneider Erik K. , Straßner Annika , Theisen Marvin , Kruppa Sebastian V. , Weis Patrick , Kappes Manfred M. , Riehn Christoph , Johnson Mark A. , Niedner‐Schatteburg Gereon 
Published: October 2021

AbstractWe report the binding geometries of the isomers that are formed when the hydrogen oxalate ((CO2)2H=HOx) anion attaches to dinuclear coinage metal phosphine complexes of the form [M1M2dcpm2(HOx)]+ with M=Cu, Ag and dcpm=bis(dicyclohexylphosphino)methane, abbreviated [MM]+. These structures are established by comparison of isomer‐selective experimental vibrational band patterns displayed by the cryogenically cooled and N2‐tagged cations with DFT calculations of the predicted spectra for various local minima. Two isomeric classes are identified that feature either attachment of the carboxylate oxygen atoms to the two metal centers (end‐on docking) or attachment of oxygen atoms on different carbon atoms asymmetrically to the metal ions (side‐on docking). Within each class, there are additional isomeric variations according to the orientation of the OH group. This behavior indicates that HOx undergoes strong and directional coordination to [CuCu]+ but adopts a more flexible coordination to [AgAg]+. Infrared spectra of the bare ions, fragmentation thresholds and ion mobility measurements are reported to explore the behaviors of the complexes at ambient temperature.
Position Matters: Fluorescent Positional Isomers for Reliable Multichannel Encryption Devices
Authors: Liu Yuxin , Seeberger Peter H. , Merbouh Nabyl , Loeffler Felix F. 
Published: October 2021

AbstractFluorescence signals have been widely used in information encryption for a few decades, but still suffer from limited reliability. Here, reversible multichannel fluorescent devices with encrypted information were constructed, based on two fluorescent positional isomers of a diphenylquinoxaline derivative. Possessing the same core fluorescent group and acid‐/pH‐responsive mechanism, the two isomers showed different fluorescence colors in an acidic environment; this allowed us to realize stepwise encryption of information in orthogonal fluorescence channels. Because the protonation was reversible, the revealed information could be re‐encrypted simply by heating. This approach highlights the value of positional isomers to build multichannel encryption devices, improving their reliability on the molecular level.
Secondary thalamic neuroinflammation after focal cortical stroke and traumatic injury mirrors corticothalamic functional connectivity
Authors: Necula Deanna , Cho Frances S. , He Andrea , Paz Jeanne T. 
Published: October 2021

AbstractWhile cortical injuries, such as traumatic brain injury (TBI) and neocortical stroke, acutely disrupt the neocortex, most of their consequent disabilities reflect secondary injuries that develop over time. Thalamic neuroinflammation has been proposed to be a biomarker of cortical injury and of the long‐term cognitive and neurological deficits that follow. However, the extent to which thalamic neuroinflammation depends on the type of cortical injury or its location remains unknown. Using two mouse models of focal neocortical injury that do not directly damage subcortical structures—controlled cortical impact and photothrombotic ischemic stroke—we found that chronic neuroinflammation in the thalamic region mirrors the functional connections with the injured cortex, and that sensory corticothalamic regions may be more likely to sustain long‐term damage than nonsensory circuits. Currently, heterogeneous clinical outcomes complicate treatment. Understanding how thalamic inflammation depends on the injury site can aid in predicting features of subsequent deficits and lead to more effective, customized therapies.
Synthesis, Optical Properties, and Electrochemical Behavior of 5,10,15,20‐Tetraaryl‐5,15‐diazaporphyrin‐Amine Hybrids
Authors: Satoh Yuna , Fujita Yutaro , Muramatsu Naoya , Furukawa Ko , Ikoma Tadaaki , Minoura Mao , Nakano Haruyuki , Matano Yoshihiro 
Published: October 2021

AbstractThis work reports a series of covalently linked hybrids comprising 5,10,15,20‐tetraaryl‐5,15‐diazaporphyrinoids (M‐TADAP; M = Ni, Zn, Cu) and amines. M‐TADAP‐amine hybrids were prepared via the metal‐templated cyclization of the corresponding metal(II)‐dipyrrin complexes and redox reactions on the DAP unit. In the UV/vis/near‐IR absorption spectra of the hybrids containing an 18π‐electron DAP ring, broad charge‐transfer bands were observed, reflecting the electron‐donating property of the para‐aminophenyl groups and the electron‐accepting property of the 18π TADAP dication. The electrochemical behavior of the M‐TADAP‐amine hybrids was strongly dependent on the structure of the peripheral amine units. Further electrochemical oxidation of the hybrids bearing N‐Ph groups conceivably generated amine‐centered radicals, which sequentially underwent irreversible coupling to form benzidine‐linked M‐TADAP polymer films. The Ni‐TADAP‐benzidine polymer exhibited the electric conductivity of 2×10−3 S m−1.