bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of energy‐optimum aromatic extraction processes using ionic liquid [EMIM][NTf2]
Authors: McNeeley Adam , Tsai Chang‐Che , Lin Shiang‐Tai , Liu Y. A. 
Published: August 2022

AbstractThere is industrial incentive to extract aromatics from ethylene cracker feeds, but the conventional sulfolane solvent was found not economical by Meindersma and coworkers. Ionic liquids (ILs) have long been considered alternative aromatic extraction solvents. This work develops energy‐optimum aromatic extraction processes for an ethylene cracker feed using IL solvents. We avoid pitfalls of using simplified feeds and a priori thermodynamic property estimates, with the largest set of experimentally regressed UNIQUAC binary parameters for the IL, 1‐ethyl‐3‐methylimidazolium bis([trifluoromethyl]sulfonyl)imide ([EMIM][NTf2]). We screen process energy and operating conditions for [EMIM][NTf2] and sulfolane at varying aromatic feed contents and find [EMIM][NTf2] favorable at low aromatic feed contents. Adding light and heavy components of the ethylene cracker feed necessitates process modifications. Our novel steam‐assisted extractive distillation developed for [EMIM][NTf2] is also suitable for sulfolane. We show that the [EMIM][NTf2] solvent can reduce 10.7% of energy consumption compared to sulfolane using the same novel process.
Electrocatalytic Hydrogenation and Reductive Coupling of Aryl Ketones: Highly efficient Straightforward Metal‐Free Access to Alcohols and Pinacols
Authors: Chowdhury Sushobhan , Kumar Ajay , Kumar Ajay 
Published: August 2022

AbstractAn electrocatalytic pathway is disclosed for the hydrogenation and reductive pinacol coupling of aryl ketones. The operationally simple protocol neither requires an external catalyst nor any sacrificial anode and proceeds efficiently under the aerobic condition at an ambient temperature and pressure. Under the optimized condition, diaryl ketones transform completely to the corresponding diarylmethanols whereas aryl ketones undergo reductive pinacol coupling leading to the respective 1,2‐diol compounds in good to excellent yields. The protocol showed a high degree of substrate compatibility with moderate to very good diastereoselectivity depending on the substrates. The scope of the developed method was also extended to the different bioactive molecules opening up the possibility for their late‐stage synthetic modification.
Programming and Dynamic Control of the Circular Polarization of Luminescence from an Achiral Fluorescent Dye in a Liquid Crystal Host by Molecular Motors
Authors: Hou Jiaxin , Toyoda Ryojun , Meskers Stefan C. J. , Feringa Ben L. 
Published: August 2022

AbstractCircular polarized light is utilized in communication and display technologies and a major challenge is to develop systems that can be switched between left and right circular polarized luminescence with high degrees of polarization and enable multiple addressable stable states. Luminescent dyes in Liquid Crystal (LC) cholesteric phases are attractive systems to generate, amplify and modulate circularly polarized luminescence (CPL). In the present study, we employ light‐driven molecular motors as photo‐controlled chiral dopants in LCs to switch the handedness of the LC and the circular polarization of luminescence from an achiral dye embedded in the mesogenic material. Tuning of the color of the CPL and the retention time of the photoprogrammed helicity is demonstrated making use of a variety of motors and dyes. The flexibility offered by the design based on inherently chiral unidirectional rotary motors provides full control over CPL non‐invasively by light, opening possibilities for pixilated displays with externally addressable polarization.
Influence of the Building Unit on Covalent Organic Frameworks in Mediating Photo‐induced Energy‐Transfer Reversible Complexation‐Mediated Radical Polymerization (PET‐RCMP)
Authors: Lu Zhen , Zhao Rui , Yang Hongjie , Fu Xiaoling , Zhao Yulai , Xiao Longqiang , Hou Linxi 
Published: August 2022

AbstractTwo imine‐based covalent organic framework photocatalysts with different building units, TPB‐DMTA‐COF and TAT‐DMTA‐COF, for photo‐induced energy transfer reversible complexation‐mediated radical polymerization (PET‐RCMP) were developed and investigated, producing ideal polymers with accurate molecular weight and moderate dispersity under visible light irradiation. The chain extension and spatiotemporal control experiments revealed the high chain‐end fidelity of polymers and the compatibility of RCMP processes in both bulk and aqueous system. Moreover, density functional theory (DFT) calculations verified that heteroatom‐doped TAT‐DMTA‐COF exhibits higher activities for weakening C−I bond energy barrier, which promotes PET‐RCMP polymerization performance. This work demonstrates that rational adjustment of building block for constructing COF heterogeneous photocatalyst can enhance the catalytic performance of PET‐RCMP, providing a design methodology for the development of polymeric organic photoelectric semiconductor catalysts to mediate RCMP.
Insight into the Overlooked Photochemical Decomposition of Atmospheric Surface Nitrates Triggered by Visible Light
Authors: Wang Hong , Sun Yanjuan , Dong Fan 
Published: August 2022

AbstractThe nitrogen oxides (NOx) formed by photochemical reaction of surface nitrates raise significant concerns. However, little is known about the effect of visible light (>380 nm) on nitrate decomposition and the reaction mechanism. Herein, the decomposition of surface nitrates is investigated under visible light. The results indicate that visible light photocatalysis contributes significantly to nitrate decomposition. Monodentate nitrate (m‐NO3−) can be decomposed into NOx by photogenerated electrons starting from the weakly coordinated N−O bond. Water vapor promotes NOx generation because more stable bidentate nitrate (b‐NO3−) will be converted into m‐NO3− by surface hydroxyl groups through hydrogen bonding interactions. Alternatively, b‐NO3− can be directly decomposed to NO2− by NO attack, but this process is subject to photocatalytic oxidation. This work brings a new focus on the atmospheric NOx sources and provides a more nuanced understanding of nitrates decomposition processes.
Multidentate Chelation Heals Structural Imperfections for Minimized Recombination Loss in Lead‐Free Perovskite Solar Cells
Authors: Liu Gengling , Zhong Yang , Feng Wenhuai , Yang Meifang , Yang Guo , Zhong Jun‐Xing , Tian Tian , Luo Jian‐Bin , Tao Junlei , Yang Shaopeng , Wang Xu‐Dong , Tan Licheng , Chen Yiwang , Wu Wu‐Qiang 
Published: August 2022

AbstractTin‐based perovskite solar cells (Sn‐PSCs) have emerged as promising environmentally viable photovoltaic technologies, but still suffer from severe non‐radiative recombination loss due to the presence of abundant deep‐level defects in the perovskite film and under‐optimized carrier dynamics throughout the device. Herein, we healed the structural imperfections of Sn perovskites in an “inside‐out” manner by incorporating a new class of biocompatible chelating agent with multidentate claws, namely, 2‐Guanidinoacetic acid (GAA), which passivated a variety of deep‐level Sn‐related and I‐related defects, cooperatively reinforced the passivation efficacy, released the lattice strain, improved the structural toughness, and promoted the carrier transport of Sn perovskites. Encouragingly, an efficiency of 13.7 % with a small voltage deficit of ≈0.47 V has been achieved for the GAA‐modified Sn‐PSCs. GAA modification also extended the lifespan of Sn‐PSCs over 1200 hours.
Rapid Access to Diverse Multicomponent Hierarchical Nanostructures from Mixed‐Graft Block Copolymers
Authors: Liang Ruiqi , Song Qingliang , Li Ruipeng , Le An N. , Fu Xiaowei , Xue Yazhen , Ji Xiaoyu , Li Weihua , Zhong Mingjiang 
Published: August 2022

AbstractMulticomponent nanostructured materials assembled from molecular building blocks received wide attention due to their precisely integrated multifunctionalities. However, discovery of these materials with desirable composition and morphology was limited by their low synthetic scalability and narrow structural tuning window with given building blocks. Here, we report a scalable and diversity‐oriented synthetic approach to hierarchically structured nanomaterials based on a few readily accessible building blocks. Mixed‐graft block copolymers containing sequence‐defined side chains were prepared through ring‐opening metathesis copolymerization of three or four types of macromonomers. Intramolecularly defined interfaces promoted the formation of ordered hierarchical structures with lattice sizes tunable across multiple length scales. The same set of macromonomers were arranged and combined in different ways, providing access to diverse morphologies in the resultant structures.
Evolution of a Strategy for Concise Enantioselective Total Synthesis of the Salinosporamide Family of Natural Products
Authors: Park Soojun , Lee Jiwoo , Kim Jae Hyun , Jeong Yeji , Lee Seokwoo , Lee Su Won , Kim Sanghee 
Published: August 2022

AbstractOur first strategy for rapidly accessing pyrrolidinone cores of salinosporamides involved combined use of memory of chirality and dynamic kinetic resolution principles in aldol reactions of the serine‐derived 5‐oxazolidinone substrate, which was ultimately unsuccessful with respect to enantioselectivity. This failure led us to the revised strategy. The influence of the stereocenter in 5‐oxazolidinone enabled selective installation of the C‐2 stereocenter. The intramolecular aldol reaction of the C‐2 stereodefined aldol substrate was successful. An unexpected hydrolytic dynamic kinetic resolution was observed in hydrolyses of the bicyclic aldol products. This unprecedented substrate‐driven hydrolytic dynamic kinetic resolution was utilized in preparing the pyrrolidinone core with excellent efficiency. Through this strategy, the concise total syntheses of salinosporamides A and B as well as cinnabaramides A, E, and F were achieved with high selectivity.
Ein pas de deux eines NO‐Paares: synchrones lichtinduziertes Schalten von einem doppelt‐linearen zu einem doppelt‐gewinkelten Ru(NO)2‐Fragment bei gleich bleibender Nitrosylladung
Authors: Hasil Asma , Beck Daniel , Schröder Daniel , Pillet Sébastien , Wenger Emmanuel , Woike Theo , Klüfers Peter , Schaniel Dominik 
Published: August 2022

AbstractDer {Ru(NO)2}10‐Dinitrosylrutheniumkomplex [Ru(NO)2(PPh3)2] (1) zeigt eine besondere Form lichtinduzierter Bindungsisomerie (PLI von photoinduced linkage isomerism): die beiden NO‐Liganden schalten bei Photoanregung synchron aus dem Grundzustand (GS) mit zwei annähernd linearen RuNO‐Funktionen in einen metastabilen Zustand (MS), der unter 230 K beständig ist und zu ≈50 % populiert werden kann. Der MS wurde experimentell durch Photokristallographie, IR‐Spektroskopie und DS‐Kalorimetrie als eine doppelt‐gewinkelte Variante des doppelt‐linearen GS charakterisiert. Die experimentellen Ergebnisse werden durch Rechnungen bestätigt – und um den Befund erweitert, dass der Übergang eine disrotatorische, synchrone 50°‐Drehung der beiden Nitrosylliganden ist. Obwohl 1 die übliche Rotverschiebung der N−O‐Valenzschwingung bei der Abwinkelung einer MNO‐Einheit zeigt, gibt es keine erhöhte Ladungsübertragung von Ru zu NO auf dem GS‐zu‐MS‐Pfad. Die Behandlung durch die Methode der effektiven Oxidationsstufe (EOS) zeigt beide Isomere von 1 und auch den Übergangszustand als Ru−II(NO+)2‐Spezies.
Die Einführung des Perfluorierten Cp*‐Liganden in die Koordinationschemie
Authors: Sievers Robin , Sellin Malte , Rupf Susanne M. , Parche Joshua , Malischewski Moritz 
Published: August 2022

AbstractDie Reaktion zwischen AgBF4 und [Rh(COD)Cl]2 (COD=1,5‐Cyclooctadien) in Gegenwart von [NEt4][C5(CF3)5] ergab den perfluorcarbonlöslichen Komplex [Rh(COD)(C5(CF3)5)] durch Salzmetathese. Dieser Komplex stellt das erste Beispiel für eine erfolgreiche Koordination des schwach basischen [C5(CF3)5]−‐Liganden, seit dessen Erstsynthese im Jahr 1980 dar. Zusätzlich zu [Rh(COD)(C5(CF3)5)] wurde das Nebenprodukt [Rh(COD)(C5(CF3)4H)] isoliert und vollständig charakterisiert. Begleitende DFT‐Rechnungen zeigen, dass die Interaktionsenergie des [C5(CF3)5]−‐Liganden gegenüber dem 12‐Elektronen [Rh(COD)]+‐Fragment aufgrund verringerter elektrostatischer Interaktionen und einer schwächeren π‐Donorfähigkeit um ≈70 kcal mol−1 im Vergleich zu [C5(CH3)5]− erniedrigt ist. Die quantitative, jedoch reversible Substitution des [C5(CF3)5]−‐Liganden durch Toluol, die ihn in ein schwach koordinierendes Anion überführt, demonstriert experimentell die außergewöhnlich schwache Bindungssituation.
Hydrogen Bonding Directed Reversal of 13C NMR Chemical Shielding
Authors: Jena Subhrakant , Routray Chinmay , Dutta Juhi , Biswal Himansu S. 
Published: August 2022

AbstractThe deshielding or downfield 13C NMR chemical shift of amide carbonyl carbon upon H‐bonding is a widely observed phenomenon. This downfield shift is commonly used as a spectroscopic ruler for H‐bonding. However, the very first observation of an upfield 13C NMR of thiocarbonyl carbon in thioamides upon H‐bonding encouraged us to explore the physical origin of the reversal of 13C NMR chemical shielding. Careful NMR analysis shows that sulfur and selenium‐centered H‐bonds (S/SeCHBs) induce a shielding effect on the 13CC=S(Se) while changing from amides to thioamides or selenoamides. In addition, natural chemical shielding (NCS) analysis shows that the σ11 and σ22 components of the isotropic shielding tensor (σ) have a crucial role in this unusual shielding.
Scaling Catalytic Contributions of Small Self‐Cleaving Ribozymes
Authors: Egger Michaela , Bereiter Raphael , Mair Stefan , Micura Ronald 
Published: August 2022

AbstractNucleolytic ribozymes utilize general acid‐base catalysis to perform phosphodiester cleavage. In most ribozyme classes, a conserved active site guanosine is positioned to act as general base, thereby activating the 2′‐OH group to attack the scissile phosphate (γ‐catalysis). Here, we present an atomic mutagenesis study for the pistol ribozyme class. Strikingly, “general base knockout” by replacement of the guanine N1 atom by carbon results in only 2.7‐fold decreased rate. Therefore, the common view that γ‐catalysis critically depends on the N1 moiety becomes challenged. For pistol ribozymes we found that γ‐catalysis is subordinate in overall catalysis, made up by two other catalytic factors (α and δ). Our approach allows scaling of the different catalytic contributions (α, β, γ, δ) with unprecedented precision and paves the way for a thorough mechanistic understanding of nucleolytic ribozymes with active site guanines.
Stereoselective Three‐Step One‐Pot Cascade Combining Amino‐ and Biocatalysis to Access Chiral γ‐Nitro Alcohols**
Authors: Ascaso‐Alegre Christian , Herrera Raquel P. , Mangas‐Sánchez Juan 
Published: August 2022

AbstractThe combination of small‐molecule catalysis and enzyme catalysis represents an underexploited area of research with huge potential in asymmetric synthetic chemistry due to both compatibility of reaction conditions and complementary reactivity. Herein, we describe the telescopic synthesis of chiral nitro alcohols starting from commercially available benzaldehyde derivatives through the one‐pot three‐step chemoenzymatic cascade combination of a Wittig reaction, chiral‐thiourea‐catalysed asymmetric conjugate addition, and ketoreductase‐mediated reduction to access the corresponding target compounds in moderate to excellent overall isolated yields (36–80 %) and high diastereomeric and enantiomeric ratios (up to >97 : 3). This represents the first example of the combination of an organocatalysed asymmetric conjugate addition via iminium ion activation and a bioreduction step catalysed by ketoreductases.
Multiple‐Resonance‐Induced Thermally Activated Delayed Fluorescence Materials Based on Indolo[3,2,1‐jk]carbazole with an Efficient Narrowband Pure‐Green Electroluminescence
Authors: Luo Xu‐Feng , Song Shi‐Quan , Ni Hua‐Xiu , Ma Huili , Yang Dezhi , Ma Dongge , Zheng You‐Xuan , Zuo Jing‐Lin 
Published: August 2022

AbstractHerein, we report two multiple‐resonance thermally activated delayed fluorescence emitters (VTCzBN and TCz‐VTCzBN) based on indolo[3,2,1‐jk]carbazole unit and boron‐nitrogen skeletons, whose emissions peaking at 496 and 521 nm with full width at half maximum of 34 and 29 nm, respectively. Meanwhile, fast rate constants of reverse intersystem crossing of above 106 s−1are obtained due to small singlet‐triplet energy gaps and large spin‐orbital coupling values. Notably, planar molecular structures along the transition dipole moment direction endow them with high horizontal emitting dipole ratios of up to 94 %. Consequently, the corresponding organic light‐emitting diodes (OLEDs) show the maximum external quantum efficiencies of 31.7 % and 32.2 %, respectively. Particularly, OLED with TCz‐VTCzBN display ultra‐pure green emission with Commission Internationale de l′Eclairage coordinates of (0.22, 0.71), consistent with the green display standard of the National Television System Committee.
Less is More: A Shortcut for Anionocages Design Based on (RPO32−)‐Monourea Coordination
Authors: Ma Fen , Qiao Xinrui , Zuo Wei , Tao Yu , Li Anyang , Luo Zhipeng , Liu Yuqi , Liu Xueru , Wang Xiaoqing , Sun Wei , Jia Chuandong 
Published: August 2022

AbstractAnionocages have been developed as a unique family of hydrogen bonded cages. However, strategies for constructing anionocages are mainly limited to that based on (PO43−)‐bisurea coordination, neither the ligands nor the anions lack the simplicity and diversity of the maturely developed analogues based on metal coordination (i.e. metallocage). We report herein a more simple strategy for anionocages design based on (RPO32−)‐monourea coordination, utilizing monourea rather than bisurea as the hydrogen binding donor, and RPO32−rather than PO43−as the acceptor. Two fluorescent, quadruple helicate anionocages were constructed by a bis‐monourea ligand, and dianions PhOPO32−(H1) or HOPO32−(H1A), respectively, which were capable of encapsulating a series of cation guests. As revealed by molecular modeling,H1features remarkable guest‐adaptive cavity breathing without change of the quadruple helicate topology, which allowed the encapsulation of different sized guests in an “induced fit” manner.
Protection gaps in Amazon floodplains will increase with climate change: Insight from the world's largest scaled freshwater fish
Authors: Dubos Nicolas , Lenormand Maxime , Castello Leandro , Oberdorff Thierry , Guisan Antoine , Luque Sandra 
Published: August 2022

Abstract

The Amazon floodplains represent important surfaces of highly valuable ecosystems, yet they remain neglected from protected areas. Although the efficiency of the protected area network of the Amazon basin may be jeopardized by climate change, floodplains are exposed to important consequences of climate change but are omitted from species distribution models and protection gap analyses.
The present and future (2070) distribution of the giant bony‐tongue fish Arapaima spp. (Arapaimidae) was modelled accounting for climate and habitat requirements, and with a consideration of dam presence (already existing and planned constructions) and hydroperiod (high‐ and low‐water stages). The amount of suitable environment that falls inside and outside the current network of protected areas was quantified to identify spatial conservation gaps.
We predict that climate change will cause a decline in environmental suitability by 16.6% during the high‐water stage, and by 19.4% during the low‐water stage. About 70% of the suitable environments of Arapaima spp. remain currently unprotected. The gap is higher by 0.7% during the low‐water stage. The lack of protection is likely to increase by 5% with future climate change effects. Both existing and projected dam constructions may hamper population flows between the central, Bolivian and Peruvian parts of the basin.
We highlight protection gaps mostly in the south‐western part of the basin and recommend the extension of the current network of protected areas in the floodplains of the upper Ucayali, Juruà and Purus rivers and their tributaries. This study has shown the importance of integrating hydroperiod and dispersal barriers in forecasting the distribution of freshwater fish species, and stresses the urgent need to integrate floodplains within the protected area networks.
Engineering Escherichia coli asymmetry distribution‐based synthetic consortium for shikimate production
Authors: Ding Qiang , Li Zhendong , Guo Liang , Song Wei , Wu Jing , Chen Xiulai , Liu Liming , Gao Cong 
Published: August 2022

AbstractMicrobial consortia constitute a promising tool for achieving high‐value chemical bio‐production. However, customizing the consortium ratio remains challenging. Herein, an asymmetry distribution‐based synthetic consortium (ADSC) was developed to switch cell phenotypes using shikimate synthesis for proof of concept. First, the cell pole‐organizing protein PopZ was screened as a mediator of asymmetric protein distribution in Escherichia coli. The ADSC was then constructed to incorporate PopZ‐mediated asymmetry distribution and a TetR‐based transcription repression switch to achieve the dynamical control of microbial population ratio. Finally, the ADSC was used to decouple cell growth from shikimate synthesis by effectively coordinating the ratio of growing cells and production cells at the consortium level, thereby increasing shikimate titer to 30.1 g/L in the 7.5‐L bioreactor with a minimal medium. This titer was further improved to 82.5 g/L when using rich medium fermentation. Our results illustrate a novel approach to control consortium structure through ADSC‐mediated regulation, highlighting its potential as an efficient strategy for controlling metabolic state in microbes.
Impact of COVID‐19 on the incidence of localized and metastatic prostate cancer among White and Black Veterans
Authors: Lee Kyung Min , Bryant Alex K. , Alba Patrick , Anglin Tori , Robison Brian , Rose Brent S. , Lynch Julie A. 
Published: August 2022

AbstractThe COVID‐19 pandemic disrupted prostate‐specific antigen (PSA) screening and prostate biopsy procedures. We sought to determine whether delayed screening and diagnostic workup of prostate cancer (PCa) was associated with increased subsequent rates of incident PCa and advanced PCa and whether the rates differed by race. We analyzed data from the Veterans Health Administration to assess the changes in the rates of PSA screening, prostate biopsy procedure, incident PCa, PCa with high‐grade Gleason score, and incident metastatic prostate cancer (mPCa) before and after January 2020. While the late pandemic mPCa rate among White Veterans was comparable to the pre‐pandemic rate (5.4 pre‐pandemic vs 5.2 late‐pandemic, p = 0.67), we observed a significant increase in incident mPCa cases among Black Veterans in the late pandemic period (8.1 pre‐pandemic vs 11.3 late‐pandemic, p < 0.001). Further investigation is warranted to fully understand the impact of the COVID‐19 pandemic on the diagnosis of advanced prostate cancer.