bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dichroic Plasmon Superstructures of Au Nanorods over Macroscopic Areas via Directed Self‐Assemblies of Diblock Copolymers
Authors: Kang Heejung , Kim Sung‐Soo , Yoo Seong Il , Sohn Byeong‐Hyeok 
Published: September 2019

AbstractThe ability to organize metal nanoparticles over the macroscopic length scale has fundamental implications for advanced plasmonic applications. In particular, linear assemblies of anisotropic nanorods (NRs) may represent a dichroic superstructure, in which plasmonic extinction is inherently dependent on the direction of light polarization. As plasmonic properties are interconnected with optics, electronics, catalysis, and sensing, dichroism in plasmonic systems can stimulate interesting opportunities in many fields of chemistry. However, the preparation of dichroic structures with a single orientation at the centimeter scale remains a significant challenge. Herein, directed self‐assemblies of polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA) diblock copolymers on lithographical patterns are applied to produce a linear pattern of Au NRs. Periodic nanogrooves from plasma‐etched PS‐b‐PMMA nanodomains facilitate the dense packing of Au NRs into end‐to‐end alignment, which entail strong plasmonic coupling among longitudinal plasmonic modes. Because the resulting NR assemblies have uniform orientation, their dichroic functions can be examined by conventional UV–vis spectroscopy without the aid of single‐particle measurements. Interestingly, both transverse and longitudinal localized surface plasmonic resonance peaks can be turned on and off under two polarized lights in orthogonal directions. Moreover, the resulting superstructures can be transferred onto various substrates, allowing the implantation of dichroic functions for numerous plasmonic applications.
Synthesis of Spiro‐Δ2‐Pyrrolin‐4‐One Pseudo Enantiomers via an Organocatalyzed Sulfa‐Michael/Aldol Domino Sequence
Authors: Grošelj Uroš , Ciber Luka , Gnidovec Jan , Testen Žan , Požgan Franc , Štefane Bogdan , Tavčar Gašper , Svete Jurij , Ričko Sebastijan 
Published: September 2019

AbstractΔ2‐Pyrrolin‐4‐ones undergo organocatalyzed sulfa‐Michael/aldol domino spirocyclizations with mercaptoacetaldehyde dimer. The products contain three contiguous stereocenters (ee up to 99%, dr up to 95:5, 25 examples) and can be transformed into analogues of natural products. With the use of a single catalyst, the absolute configuration of the products were determined by the configuration of the exocyclic double bond of the starting material. These results point at the possibility of a widespread use of unsaturated Δ2‐pyrrolin‐4‐ones in various (organo)catalyzed (cascade) transformations for accessing libraries of 3D‐rich pyrrolone‐based (spiro)heterocycles.magnified image
Unexpected Cascade Reactions of Ortho‐Hydroxyenaminones and β,γ‐Unsaturated α‐Ketoesters to Access Hydrogenated Benzoxazolepolycycles and Pyrrole−Phenol Atropisomers
Authors: Bai Xuguan , Wang Lele , Zhang Ziying , Zhang Kuan , Bu Zhanwei , Wu Yufeng , Zhang Wenjing , Wang Qilin 
Published: September 2019

AbstractAn unexpected BF3 ⋅ OEt2‐catalyzed Michael addition/cyclization/dehydration sequence of ortho‐hydroxyenaminones with aromatic or aliphatic aldehyde‐derived β,γ‐unsaturated α‐ketoesters has been achieved to afford a wide range of fused hydrogenated benzoxazole polycycles in 67–95% yields in a highly diastereoselective manner. When isatin‐derived β,γ‐unsaturated α‐ketoesters were employed as substrates, completely different reactivities were observed, delivering an array of new atropisomers with an oxindole‐substituted N−C axially chiral pyrrole−phenol backbone in up to 97% yield. Moreover, DFT calculations were conducted to account for the possible reaction pathway and the stereochemistry.magnified image
On the Origin of the Large Remanent Polarization in La:HfO2
Authors: Schenk Tony , Fancher Chris M. , Park Min Hyuk , Richter Claudia , Künneth Christopher , Kersch Alfred , Jones Jacob L. , Mikolajick Thomas , Schroeder Uwe 
Published: September 2019

AbstractThe outstanding remanent polarization of 40 µC cm–2 reported for a 10 nm thin La:HfO2 film in 2013 has attracted much attention. However, up to now, no explanation for this large remanent polarization has been presented. Density functional theory and X‐ray diffraction are used to shine light onto three major aspects that impact the macroscopically observed remanent polarization: phase fraction, spontaneous polarization, and crystallographic texture. Density functional theory calculations show that the spontaneous polarization (Ps) of La:HfO2 is indeed a bit larger than for other HfO2‐ or ZrO2‐based compounds; however, the Ps is not large enough to explain the observed differences in remanent polarization. While neither phase fractions nor spontaneous polarization nor strain are significantly different from those in other HfO2 films, a prominent 020/002 texture distinguishes La doped from other HfO2‐based ferroelectric films. Angular‐dependent diffraction data provide a pathway to calculate the theoretically expected remanent polarization, which is in agreement with the experimental observations. Finally, an interplay of the in‐plane strain and texture is proposed to impact the formation of the ferroelectric phase during annealing. Further aspects of the special role of La as a dopant are collected and discussed to motivate future research.
Evaporation‐Free Nonfullerene Flexible Organic Solar Cell Modules Manufactured by An All‐Solution Process
Authors: Han Yong Woon , Jeon Sung Jae , Lee Hyoung Seok , Park Hongkwan , Kim Kwang Su , Lee Ho‐Won , Moon Doo Kyung 
Published: September 2019

AbstractTo ensure laboratory‐to‐industry transfer of next‐generation energy harvesting organic solar cells (OSCs), it is necessary to develop flexible OSC modules that can be produced on a continuous roll‐to‐roll basis and to apply an all‐solution process. In this study, nonfullerene acceptors (NFAs)‐based donor polymer, SMD2, is newly designed and synthesized to continuously fabricate high‐performance flexible OSC modules. Also, multifunctional hole transport layers (HTLs), WO3/HTL solar bilayer HTLs, are developed and applied via an all‐solution process called “ProcessOne” into inverted structure. SMD2, the donor terpolymer, has a deep highest occupied molecular orbital (HOMO) level and can achieve a power conversion efficiency (PCE) of 11.3% with NFAs without any pre‐/post‐treatment because of its optimal balance between crystallinity and miscibility. Furthermore, the integration of multifunctional HTLs enables the recovery of the drop in open circuit voltage (VOC) caused by a mismatch in energy levels between the deep HOMO level of the NFAs‐based bulk‐heterojunction layer and the solution‐processed HTLs. Also, the photostability under ultraviolet‐exposure necessary for “ProcessOne” is greatly improved because of the integration of multifunctional HTLs. Consequently, because of the synergistic effects of these approaches, the flexible OSC modules fabricated in an industrial production line have a PCE of 5.25% (Pmax = 419.6 mW) on an active area of 80 cm2.
How to build distylous flowers: comparative floral development and evolution of distylous species across the angiosperms
Authors: Cohen James I. 
Published: September 2019

PremiseDistyly, a plant breeding system characterized by two floral morphs that have reciprocal positioning of anthers and stigmas, is known from at least 27 angiosperm families, making it an excellent example of convergent evolution. The various manners in which patterns of floral development produce the distinct anther and stigma heights in each morph remain largely unexplored from developmental and evolutionary perspectives.MethodsIn 15 species representing at least 12 origins of distyly, heights and lengths of floral organs in each morph throughout development were examined using light microscopy. Patterns of floral organ development were determined and compared among species. Family‐level phylogenies of distylous species and relatives were reconstructed, and patterns of ancestral herkogamy were resolved.ResultsDifferences in floral development between morphs resulted in 12 patterns leading to the anther and stigma positions characterizing distyly. Distylous species evolved from ancestors with different types of herkogamy, with approach herkogamy and lack of herkogamy resolved most frequently.ConclusionsSeven of the 12 patterns of floral development are known from only one species, with three other patterns described among pairs of close relatives. The most common pattern of floral development, described from at least seven genera, involves for anther heights, distinct intermorph growth rates and for stigma heights, growth rates that differ between morphs only during later development. This pattern is common among subclass Lamiidae, suggesting canalized development within the taxon. Among distylous species, the same type of ancestral herkogamy can give rise to different patterns of floral development.
Hybrid Halide Perovskites: Discussions on Terminology and Materials
Authors: Mercier Nicolas 
Published: September 2019

AbstractHybrid halide perovskites (HP) have emerged in the last decade as a new class of semiconductors with superior performances in photovoltaic and electronic devices. The literature about these halide semiconductors is abundant and a lot of names/expressions are used to define networks, structures, or materials. In this context, there is a need to offer some discussions about the relevance of using the word “perovskite” and the associated expressions (“RP” (Ruddlesden–Popper), “DJ” (Dion–Jacobson), “ACI” (alternating cations in the interlayer space), “hexagonal perovskites”, “hollow perovskites”, “d‐HP” (deficient 3D HP),…). Moreover, the description of perovskite networks through elimination/substitution processes from the ABX3 structure will be compared to the known dimensional reduction concept.
Palladium(0)‐Catalyzed Directed syn‐1,2‐Carboboration and ‐Silylation: Alkene Scope, Applications in Dearomatization, and Stereocontrol by a Chiral Auxiliary
Authors: Liu Zhen , Chen Jiahao , Lu Hou‐Xiang , Li Xiaohan , Gao Yang , Coombs John R. , Goldfogel Matthew J. , Engle Keary M. 
Published: September 2019

AbstractWe report the development of palladium(0)‐catalyzed syn‐selective 1,2‐carboboration and ‐silylation reactions of alkenes containing cleavable directing groups. With B2pin2 or PhMe2Si‐Bpin as nucleophiles and aryl/alkenyl triflates as electrophiles, a broad range of mono‐, di‐, tri‐ and tetrasubstituted alkenes are compatible in these transformations. We further describe a directed dearomative 1,2‐carboboration of electron‐rich heteroarenes by employing this approach. Through use of a removable chiral directing group, we demonstrate the viability of achieving stereoinduction in Heck‐type alkene 1,2‐difunctionalization. This work introduces new avenues to access highly functionalized boronates and silanes with precise regio‐ and stereocontrol.
Controlling the Reactivity of the [P8W48O184]40− Inorganic Ring and Its Assembly into POMZite Inorganic Frameworks with Silver Ions
Authors: Zhan Cai‐Hong , Zheng Qi , Long De‐Liang , Vilà‐Nadal Laia , Cronin Leroy 
Published: September 2019

AbstractThe construction of pure‐inorganic framework materials with well‐defined design rules and building blocks is challenging. In this work, we show how a polyoxometalate cluster with an integrated pore, based on [P8W48O184]40− (abbreviated as {P8W48}), can be self‐assembled into inorganic frameworks using silver ions, which both enable reactions on the cluster as well as link them together. The {P8W48} was found to be highly reactive with silver ions resulting in the in situ generation of fragments, forming {P9W63O235} and {P10W66O251} in compound (1) where these two clusters co‐crystallize and are connected into a POMZite framework with 11 Ag+ ions as linkers located inside clusters and 10 Ag+ linking ions situated between clusters. Decreasing both the concentration of Ag+ ions, and the reaction temperature compared to the synthesis of compound (1), leads to {P8W51O196} in compound 2 where the {P8W48} clusters are linked to form a new POMZite framework with 9 Ag+ ions per formula unit. Further tuning of the reaction conditions yields a cubic porous network compound (3) where {P8W48} clusters as cubic sides are joined by 4 Ag+ ions to give a cubic array and no Ag+ ions were found inside the clusters.
In‐Operando Mapping of pH Distribution in Electrochemical Processes
Authors: Fuladpanjeh‐Hojaghan Behzad , Elsutohy Mohamed M. , Kabanov Vladimir , Heyne Belinda , Trifkovic Milana , Roberts Edward P. L. 
Published: September 2019

AbstractIn aqueous electrochemical processes, the pH evolves spatially and temporally, and often dictates the process performance. Herein, a new method for the in‐operando monitoring of pH distribution in an electrochemical cell is demonstrated. A combination of pH‐sensitive fluorescent dyes, encompassing a wide pH range from ≈1.5 to 8.5, and rapid electrochemically coupled laser scanning confocal microscopy is used to observe pH changes in the cell. Using electrocoagulation as an example process, we show that the method provides new insights into the reaction mechanisms. The pH close to the aluminium electrode surface is influenced by the applied current density, hydrolysis of aluminium cations, and gas evolution. Through quantification of the pH at the anode, along with gas analysis, we find that hydrogen is evolved at the anode due to a non‐Faradaic chemical reaction. This leads to increased production of coagulant, which may open new routes to enhance the process performance. This method for in‐operando dynamic visualization of pH paves the way for studies of electrochemical processes, including other water treatment, electrosynthesis, and batteries.
Intermolecular Carbonyl–olefin Metathesis with Vinyl Ethers Catalyzed by Homogeneous and Solid Acids in Flow
Authors: Rivero‐Crespo Miguel Ángel , Tejeda‐Serrano María , Pérez‐Sánchez Horacio , Cerón‐Carrasco José Pedro , Leyva‐Pérez Antonio 
Published: September 2019

AbstractThe carbonyl–olefin metathesis reaction has experienced significant advances in the last seven years with new catalysts and reaction protocols. However, most of these procedures involve soluble catalysts for intramolecular reactions in batch. Herein, we show that recoverable, inexpensive, easy to handle, non‐toxic, and widely available simple solid acids, such as the aluminosilicate montmorillonite, can catalyze the intermolecular carbonyl–olefin metathesis of aromatic ketones and aldehydes with vinyl ethers in‐flow, to give alkenes with complete trans stereoselectivity on multi‐gram scale and high yields. Experimental and computational data support a mechanism based on a carbocation‐induced Grob fragmentation. These results open the way for the industrial implementation of carbonyl–olefin metathesis over solid catalysts in continuous mode, which is still the origin and main application of the parent alkene–alkene cross‐metathesis.
A Chalcogen‐Bonding Cascade Switch for Planarizable Push–Pull Probes
Authors: Macchione Mariano , Goujon Antoine , Strakova Karolina , Humeniuk Heorhii V. , Licari Giuseppe , Tajkhorshid Emad , Sakai Naomi , Matile Stefan 
Published: September 2019

AbstractPlanarizable push–pull probes have been introduced to demonstrate physical forces in biology. However, the donors and acceptors needed to polarize mechanically planarized probes are incompatible with their twisted resting state. The objective of this study was to overcome this “flipper dilemma” with chalcogen‐bonding cascade switches that turn on donors and acceptors only in response to mechanical planarization of the probe. This concept is explored by molecular dynamics simulations as well as chemical double‐mutant cycle analysis. Cascade switched flipper probes turn out to excel with chemical stability, red shifts adding up to high significance, and focused mechanosensitivity. Most important, however, is the introduction of a new, general and fundamental concept that operates with non‐trivial supramolecular chemistry, solves an important practical problem and opens a wide chemical space.
Synthesis and Self‐assembly of a Helical Polymer Grafted from a Foldable Polyurethane Scaffold
Authors: Barman Ranajit , Dey Pradip , Mondal Tathagata , Ghosh Suhrit 
Published: September 2019

AbstractHerein a polyurethane graft poly‐l‐glutamate amphiphilic copolymer was synthesized from a polyurethane (PU)‐based macro‐initiator (containing pendant primary amine groups) through the ring opening polymerization of N‐carboxy anhydride of γ‐benzyl‐l‐glutamate (BLG‐NCA). On average, twenty two l‐glutamic acids were grafted from each amino group which was pendant on the polyurethane chain with 10 repeating units. The grafted polymer (PU‐PP‐1) exhibits self‐assembly to produce a hydrogel in a wide pH window ranging from pH 5.0 to 8.0 with a critical gelation concentration (CGC) of 5.0 wt % (w/v) at pH 7.4. Furthermore, circular dichroism study revealed the transition of the α‐helix to a random coil upon increasing the pH. Due to the protonation of side chains at pH 4.0, PU‐PP‐1 adopted an α‐helical conformation whereas at pH >8.0 the side‐chain carboxylic acid groups of the PLGAs were ionized, leading to the formation of an extended random coil conformation as a result of charge repulsion. Conformational switching was also supported by FTIR spectroscopy.
Benzylamine as Hydrogen Transfer Agent: Cobalt‐Catalyzed Chemoselective C=C Bond Reduction of β‐Trifluoromethylated α,β‐Unsaturated Ketones via 1,5‐Hydrogen Transfer
Authors: Li Xuewei , Wu Xiaoting , Tang Liang , Xie Fang , Zhang Wanbin 
Published: September 2019

AbstractAn efficient cobalt‐catalyzed chemoselective reduction of β‐CF3‐α,β‐unsaturated ketones using benzylamine as hydrogen transfer agent involving intramolecular 1,5‐hydrogen transfer is reported. The reaction proceeded smoothly with a relatively wide range of substrates including those bearing aromatic heterocycles such as a furyl ring system in high yields (74–92 %). This provides an efficient method for the synthesis of β‐CF3 saturated ketones in one‐pot. This methodology was also applied to the selective C=C reduction of other enone substrates bearing no β‐CF3‐substituent, of which β‐substituted or β,β‐disubstituted enones are tolerated, giving the desired products in good yields (72–75 %). Mechanistic studies indicate that the reaction involves 1,5‐hydrogen transfer.
Combination of rice varieties and cooking methods resulting in a high content of resistant starch
Authors: Kim Ha Ram , Hong Jung Sun , Ryu A‐Reum , Choi Hee‐Don 
Published: September 2019

AbstractBackground and objectivesWith the interest in increasing resistant starch (RS) of cooked rice, lowering its digestibility has been attempted but not established yet. Herein, we aimed to develop a simple cost‐effective method to prepare RS‐enriched cooked rice. Various combinations of rice types, cooking methods, and additives were investigated to increase the RS content.FindingsThe high‐amylose cultivar (~28% amylose), retort‐type cooking (121°C, 30 min, 15 psi), and brown rice resulted in higher RS content than that of normal rice, conventional cooking, and white rice, respectively. The effect of various food additives in soaking water on additional RS formation was marginal except for citric acid or soybean oil.ConclusionsThe method for producing RS‐enriched cooked rice was successfully established using high‐amylose brown rice via soaking in 30–40 mg/ml citric acid solution, retort‐type cooking, and drying. Its high RS content is likely due to collective effects from starch retrogradation, amylose‐lipid complex, restricted starch swelling/gelatinization by bran layer and non‐starch dietary fiber, and chemical cross‐linking.Significance and noveltyA simple cost‐effective method was developed resulting in the highest RS content reported to date for intact cooked rice (7.60%), which can be consumed as‐is or as a rice product ingredient requiring low glycemic index properties.
Deracemization in a Complex Quaternary System with a Second‐Order Asymmetric Transformation by Using Phase Diagram Studies
Authors: Oketani Ryusei , Marin Francesco , Tinnemans Paul , Hoquante Marine , Laurent Anne , Brandel Clément , Cardinael Pascal , Meekes Hugo , Vlieg Elias , Geerts Yves , Coquerel Gérard 
Published: September 2019

AbstractInvited for the cover of this issue is the group of Gérard Coquerel at Université de Rouen Normandie. The image depicts a pyramid‐like tetrahedron of the quaternary phase diagram showing where symmetry breaking can take place. Read the full text of the article at 10.1002/chem.201903338.
Acceptance and commitment therapy for breast cancer survivors with fear of cancer recurrence: A 3‐arm pilot randomized controlled trial
Authors: Johns Shelley A. , Stutz Patrick V. , Talib Tasneem L. , Cohee Andrea A. , Beck‐Coon Kathleen A. , Brown Linda F. , Wilhelm Laura R. , Monahan Patrick O. , LaPradd Michelle L. , Champion Victoria L. , Miller Kathy D. , Giesler R. Brian 
Published: September 2019

BackgroundFear of cancer recurrence (FCR) has a profound negative impact on quality of life (QOL) for many cancer survivors. Breast cancer survivors (BCS) are particularly vulnerable, with up to 70% reporting clinically significant FCR. To the authors' knowledge, evidence‐based interventions for managing FCR are limited. Acceptance and commitment therapy (ACT) promotes psychological flexibility in managing life's stressors. The current study examined the feasibility and preliminary efficacy of group‐based ACT for FCR in BCS.MethodsPost‐treatment BCS (91 patients with stage I‐III disease) with clinical FCR randomly were assigned to ACT (6 weekly 2‐hour group sessions), survivorship education (SE; 6 weekly 2‐hour group sessions), or enhanced usual care (EUC; one 30‐minute group coaching session with survivorship readings). FCR severity (primary outcome) and avoidant coping, anxiety, post‐traumatic stress, depression, QOL, and other FCR‐related variables (secondary outcomes) were assessed at baseline (T1), after the intervention (T2), 1 month after the intervention (T3), and 6 months after the intervention (T4) using intent‐to‐treat analysis.ResultsSatisfactory recruitment (43.8%) and retention (94.5%) rates demonstrated feasibility. Although each arm demonstrated within‐group reductions in FCR severity over time, only ACT produced significant reductions at each time point compared with baseline, with between‐group differences at T4 substantially favoring ACT over SE (Cohen d for effect sizes, 0.80; P < .001) and EUC (Cohen d, 0.61; P < .01). For 10 of 12 secondary outcomes, only ACT produced significant within‐group reductions across all time points. By T4, significant moderate to large between‐group comparisons favored ACT over SE and EUC with regard to avoidant coping, anxiety, depression, QOL, and FCR‐related psychological distress.ConclusionsGroup‐based ACT is a feasible and promising treatment for FCR and associated outcomes in BCS that warrants testing in larger, fully powered trials.