bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid and Scalable Synthesis of Zeolitic Imidazole Framework (ZIF‐8) and its Use for the Detection of Trace Levels of Nitroaromatic Explosives
Authors: Prathap Mylamparambil Udayan Anu , Gunasekaran Sundaram 
Published: July 2018

AbstractA facile and inexpensive approach for scalable synthesis of highly porous zeolite imidazolate framework nanoparticles (ZIF‐8) is described. The synthesis, done in an aqueous solution at room temperature, takes just 2 min compared to hours or days in nonaqueous conditions. The structural integrity and phase purity of ZIF‐8 are studied through X‐ray powder diffraction and are of sodalite topology, and its surface nature and composition are determined with X‐ray photoelectron spectroscopy. ZIF‐8 has high crystallinity, large Brunauer–Emmett–Teller surface area (1398.7 m2 g−1) and pore volume (0.62 cm3 g−1). Images of ZIF‐8 show hexagonal nanocrystals, whose growth is observed with atomic force microscopy (AFM). Thermogravimetric analysis data testify the thermal stability of the material (490 °C in air). Zeta potential measurement confirms that trinitrotoluene (TNT) molecules adsorb onto ZIF‐8. The interaction between the electron‐deficient aromatic core of TNT and the electron‐rich ZIF‐8 is considered to favor the formation of donor–acceptor electron‐transfer mechanism, and the electron conductivity of ZIF‐8 facilitates the effective reduction of TNT. Using the prepared ZIF‐8, an electrochemical sensor is fabricated to detect TNT and other nitroaromatic explosives in aqueous phase. The sensor performance is highly linear, with very low limit of detection (346 × 10−12m), and is unaffected by the presence of various interferents.
Reliable and General Route to Inverse Opal Structured Nanohybrids of Carbon‐Confined Transition Metal Sulfides Quantum Dots for High‐Performance Sodium Storage
Authors: Hu Xiang , Jia Jingchun , Wang Genxiang , Chen Junxiang , Zhan Hongbing , Wen Zhenhai 
Published: July 2018

AbstractSodium‐ion batteries (SIBs) have recently attracted increasing attention as the promising alternative to lithium‐ion batteries due to their multiple advantages of abundant reserves and low cost. However, the development of highly desirable anode materials suitable for SIBs is still hampered by a rather low capacity, poor rate capability, and cycling stability. Herein, a deliberate design to implement reliable and simple fabrication of an inverse opal structured nanohybrid of carbon‐confined various transition metal sulfides quantum dots (QDs) is presented. Comprehensive characterizations demonstrate that the hybrids hold a 3D architecture with uniform dispersion of QDs in a conductive carbon matrix that in turn encapsulates these quantum dots. With Co9S8 as an example, such a unique architecture, when applied as the anode of SIBs, endows the hybrids with multiple advantages including a high reversible specific capacity, extraordinary high rate capability, and excellent durability over 2000 cycles charging–discharging process.
Catalytic Stereoselective SN1‐Type Reactions Promoted by Chiral Phosphoric Acids as Brønsted Acid Catalysts
Authors: Gualandi Andrea , Rodeghiero Giacomo , Cozzi Pier Giorgio 
Published: July 2018

AbstractIn recent years, the field of organocatalysis has extensively explored the use of carbenium ions for practical C−C bond forming reactions. In order to control the formation of new stereocenters, the generation of carbenium ions was investigated by exploring asymmetric Brønsted acid catalysis. Oxocarbenium ions, iminium ions, and other carbenium ions stabilized by heteroatoms could also be generated by Brønsted acid catalysis, through the departure of suitable leaving groups. The aforementioned reactivity has recently been exploited leading to remarkable achievements. The application of chiral Brønsted acids in the generation of heteroatom stabilized carbenium ions has recently been investigated, with the demonstration of important results. Although diverse architectural arrays of Brønsted acid catalysts were conceived, BINOL‐derived phosphoric acids have played a dominant role in this area of research. Their low pKa values combined with the possibility to alter their architecture, and their ability to assemble ordered transition states was exploited in different SN1‐type reactions allowing the formation of a variety of products with high enantiomeric excesses. In addition, the generation of highly stabilized chiral counter anions allowed the exploitation of counterion asymmetric catalysis with various nucleophiles.
Triphenylamine Functionalized Unsymmetrical Quinoxalines
Authors: Bijesh S. , Misra Rajneesh 
Published: July 2018

AbstractA family of unsymmetrical quinoxalines 11–18 of types D‐A‐π‐D and D‐A‐A′‐D′ have been designed and synthesized by the Suzuki, Heck, Sonogashira, Ullmann coupling and [2+2] cycloaddition−retroelectrocyclic ring opening reactions. A systematic study was performed to explore the effect of donor, acceptor and π‐linker on the triphenylamine functionalized quinoxalines. The electronic absorption spectra of the ethynyl bridged quinoxaline 14 show red shifted absorption in the high‐energy region compared to quinoxaline 13. The quinoxalines 17 and 18 exhibit red shifted absorption in the near–infrared (NIR) region due to the incorporation of strong TCNE/TCNQ acceptor units. The TGA data reveals that triphenylethylene substituted quinoxaline 15 shows higher thermal stability compared to other quinoxalines. The electrochemical data exhibit strong electronic communication in quinoxalines 11–18. The incorporation of TCNE/TCNQ acceptor units results in greater stabilization of LUMO levels and low HOMO−LUMO energy gap in 17 and 18 which was supported by computational studies.
Synthesis and Reversible Hydration of a Pseudoprotein, a Fully Organic Polymeric Desiccant by Multiple Single‐Crystal‐to‐Single‐Crystal Transformations
Authors: Mohanrao Raja , Sureshan Kana M. 
Published: July 2018

AbstractA diphenylalanine derivative, N3‐Phe‐Phe‐NHCH2CCH, was designed for topochemical azide–alkyne cycloaddition (TAAC) polymerization. This dipeptide adopted β‐sheet arrangement as designed, in its crystals, but the azide and alkyne were not fitly aligned for their topochemical reaction. However, the voids present around these groups allowed them to attain a reactive geometry upon heating and their consequent TAAC polymerization to a pseudoprotein in a single‐crystal‐to‐single‐crystal (SCSC) fashion. This motion led to the creation of channels in the product crystal and it absorbed water from the surroundings to fill these channels as H‐bonded water wire. The pseudoprotein undergo reversible hydration/dehydration in SCSC fashion many times under mild conditions: hydration at low relative humidity and dehydration at low temperature. Vapor sorption analyses suggest that this fully organic polymer might be useful as an energy‐efficient desiccant material for controlling indoor humidity.
Ein rotaxanartiges Käfig‐im‐Ring‐Strukturmotiv für ein metallosupramolekulares Pd6L12‐Aggregat
Authors: Käseborn Matthias , Holstein Julian J. , Clever Guido H. , Lützen Arne 
Published: July 2018

AbstractEin BODIPY‐basierter Bis(3‐pyridyl)‐Ligand bildet in einem Selbstorganisationsprozess bei der Koordination an tetravalente Palladium(II)‐Ionen ein metallosupramolekulares Pd6L12‐Aggregat mit einem neuartigen Strukturmotiv, das als ein rotaxanartiges Käfig‐im‐Ring‐Arrangement beschrieben werden kann. In diesem Assemblat nimmt der Ligand zwei unterschiedliche Konformationen ein – eine C‐förmige, um einen Pd2L4‐Käfig aufzubauen, der sich im Zentrum eines Pd4L8‐Rings befindet, welcher aus Liganden in einer W‐förmigen Konformation zusammengesetzt ist. Dieses Aggregat ist nicht im Sinne einer Katenierung mechanisch ineinander verschlungen, sondern es wird lediglich durch attraktive π‐Stapelwechselwirkungen zwischen den BODIPY‐Chromophoren in der Peripherie und den Rückgraten der Liganden sowie den Van‐der‐Waals‐Wechselwirkungen zwischen den langen Alkoxyketten stabilisiert. Durch dieses Arrangement beider Komponenten kommt es zu einem sehr effektiven Ausfüllen des Raumes. Die gesamte Struktur kann daher als ein rotaxanartiges Assemblat beschrieben werden, in dem ein metallosupramolekularer Käfig die Achse in einem metallosupramolekularen Ring bildet. Dieses einzigartige Strukturmotiv konnte mittels ESI‐Massenspektrometrie, NMR‐Spektroskopie und Einkristall‐Röntgenbeugungsexperimenten charakterisiert werden.
Heteroatom‐Doped Carbon Dots (CDs) as a Class of Metal‐Free Photocatalysts for PET‐RAFT Polymerization under Visible Light and Sunlight
Authors: Jiang Jingjie , Ye Gang , Wang Zhe , Lu Yuexiang , Chen Jing , Matyjaszewski Krzysztof 
Published: July 2018

AbstractA key challenge of photoregulated living radical polymerization is developing efficient and robust photocatalysts. Now carbon dots (CDs) have been exploited for the first time as metal‐free photocatalysts for visible‐light‐regulated reversible addition–fragmentation chain‐transfer (RAFT) polymerization. Screening of diverse heteroatom‐doped CDs suggested that the P‐ and S‐doped CDs were effective photocatalysts for RAFT polymerization under mild visible light following a photoinduced electron transfer (PET) involved oxidative quenching mechanism. PET‐RAFT polymerization of various monomers with temporal control, narrow dispersity (Đ≈1.04), and chain‐end fidelity was achieved. Besides, it was demonstrated that the CD‐catalyzed PET‐RAFT polymerization was effectively performed under natural solar irradiation.
Dissipative Selbstassemblierung photolumineszierender Siliciumnanokristalle
Authors: Grötsch Raphael K. , Angı Arzu , Mideksa Yonatan G. , Wanzke Caren , Tena‐Solsona Marta , Feige Matthias J. , Rieger Bernhard , Boekhoven Job 
Published: July 2018

AbstractLösungen von Siliciumnanokristallen (SiNCs) werden z. B. wegen ihrer einstellbaren Photolumineszenz, Biokompatibilität und der Verfügbarkeit von Si in zahlreichen Anwendungen eingesetzt. In dissipativen supramolekularen Materialien wird die Selbstassemblierung von Molekülen oder Nanopartikeln durch ein chemisches Reaktionsnetzwerk angetrieben, das irreversibel Brennstoff verbraucht. Die Eigenschaften der entstehenden Strukturen werden durch die Kinetik des zugrunde liegenden chemischen Reaktionsnetzwerkes gesteuert. Hier wird die dissipative Selbstassemblierung von photolumineszierenden SiNCs demonstriert, die von einem chemischen Brennstoff angetrieben werden. Eine chemische Reaktion setzt die Selbstassemblierung der wasserlöslichen SiNCs in Gang. Allerdings sind die Strukturen transient, und wenn dem chemischen Reaktionsnetzwerk der Brennstoff ausgeht, deassemblieren sich die SiNCs. Die Lebensdauer der Strukturen ist durch die zugegebene Brennstoffmenge steuerbar. Die Plattform kann für die gesteuerte, verzögerte Aufnahme der Nanokristalle durch Säugetierzellen genutzt werden.
Dynamic Coupling at Low Reynolds Number
Authors: Dey Krishna Kanti 
Published: July 2018

AbstractCollective and emergent behaviors of active colloids provide useful insights into the statistical physics of out‐of‐equilibrium systems. Colloidal suspensions containing microscopic active swimmers have been intensively studied to understand the principles of energy transfer at low Reynolds number conditions. Studies on active enzymes and Ångström‐sized organometallic catalysts have demonstrated that energy can even be transferred by molecules to their surroundings, thereby influencing the overall dynamics of the systems substantially. By monitoring the diffusion of non‐reacting tracers in active solutions, it has been shown that the nature of energy transfer in systems containing different swimmers is surprisingly similar—irrespective of their size, modes of energy transduction, and propulsion strategies. This Review discusses research results obtained so far in this direction, highlighting the common features observed in the dynamic coupling of swimmers with their surroundings.
Modulation of Hydrophobic Interaction by Mediating Surface Nanoscale Structure and Chemistry, not Monotonically by Hydrophobicity
Authors: Cui Xin , Liu Jing , Xie Lei , Huang Jun , Liu Qi , Israelachvili Jacob N. , Zeng Hongbo 
Published: July 2018

AbstractThe hydrophobic (HB) interaction plays a critical role in many colloidal and interfacial phenomena, biophysical and industrial processes. Surface hydrophobicity, characterized by the water contact angle, is generally considered the most dominant parameter determining the HB interaction. Herein, we quantified the HB interactions between air bubbles and a series of hydrophobic surfaces with different nanoscale structures and surface chemistry in aqueous media using a bubble probe atomic force microscopy (AFM). Surprisingly, it is discovered that surfaces of similar hydrophobicity can show different ranges of HB interactions, while surfaces of different hydrophobicity can have similar ranges of HB interaction. The increased heterogeneity of the surface nanoscale structure and chemistry can effectively decrease the decay length of HB interaction from 1.60 nm to 0.35 nm. Our work provides insights into the physical mechanism of HB interaction.
Access to P‐ and Axially Chiral Biaryl Phosphine Oxides by Enantioselective CpxIrIII‐Catalyzed C−H Arylations
Authors: Jang Yun‐Suk , Woźniak Łukasz , Pedroni Julia , Cramer Nicolai 
Published: July 2018

AbstractAn enantioselective C−H arylation of phosphine oxides with o‐quinone diazides catalyzed by an iridium(III) complex bearing an atropchiral cyclopentadienyl (Cpx) ligand and phthaloyl tert‐leucine as co‐catalyst is reported. The method allows access to a) P‐chiral biaryl phosphine oxides, b) atropo‐enantioselective construction of sterically demanding biaryl backbones, and also c) selective assembly of axial and P‐chiral compounds in excellent yields and diastereo‐ and enantioselectivities. Enantiospecific reductions provide monodentate chiral phosphorus(III) compounds having structures and biaryl backbones with proven importance as ligands in asymmetric catalysis.
The effect of electric field and Al doping on the sensitivity of hexa‐peri‐hexabenzocoronene nanographene to chloropicrin
Authors: Hosseinian Akram , Gharachorloo Arezoo , Mohazzab Lighvani Tarlan , Delir Kheirollahi Nezhad Parvaneh , Vessally Esmail 
Published: July 2018

It has been previously reported that the recently synthesized hexa‐peri‐hexabenzocoronene (HBC) nanographene cannot detect toxic chloropicrin (CP) gas. To overcome this problem, we examined the effect of Al doping and applying an electric field on the sensitivity of HBC towards CP gas by means of density functional theory calculations. We found that the Al‐doping process significantly increases the adsorption energy of CP gas from −7.1 to −39.9 kcal mol−1 but decreases the sensitivity of HBC. By applying an electric field, the HBC is polarized with two different electrostatic potentials on its different surfaces, which increases the adsorption energy. By increasing the electric field strength, the adsorption energy and electronic sensitivity of HBC are increased. We predicted that in the presence of an electric field of about −0.025 au, HBC can act as an electronic senor or a work function‐type sensor with a short recovery time. At this field, the electrical conductivity of HBC is significantly increased on CP adsorption which generates an electrical signal. Increasing the electric field to higher intensities is not favourable because of increasing recovery times, and decreasing it to lower intensities reduces the sensitivity of HBC.
p‐Toluate‐bridged dinuclear Cu(II) complexes in combination with tridentate chelating ligand: Crystal structure, density functional theory calculation, DNA/protein binding and catecholase activity
Authors: Dolai Samar , Das Kalipada , Bhunia Apurba , Bertolasi Valerio , Manna Subal Chandra 
Published: July 2018

The dinuclear Cu(II) complexes [Cu2(L1)2(mb)]⋅ClO4 (1) and [Cu2(L2)2(mb)]⋅ClO4 (2) (HL1 = 2‐[(2‐diethylaminoethylimino)methyl]phenol; HL2 = 2‐[1‐(2‐diethylaminoethylimino)propyl]phenol; mb = 4‐methylbenzoate) were synthesized and characterized using X‐ray crystal structure analysis and spectroscopic methods. Complexes 1 and 2 are dinuclear with distorted square pyramidal Cu (II) geometries, where Schiff base coordinates with tridentate (N,N,O) chelating mode and mb bridges two metal centres. Optimized structures and photophysical properties of ligands and complexes were calculated using density functional theory and time‐dependent density functional theory methods using B3LYP functional with 6‐31G (d,p) and LanL2MB basis sets. Interactions of the complexes with bovine serum albumin (BSA) and human serum albumin (HSA) were studied using UV–visible absorption and fluorescence spectroscopies and the calculated values of association constants (M−1) are 1.7 × 105 (1–BSA), 5.7 × 105 (2–BSA), 1.6 × 105 (1–HSA) and 6.9 × 105 (2–HSA). Interactions of the complexes with calf thymus DNA were also investigated and the binding affinities are 1.4 × 105 and 1.6 × 105 M−1 for 1 and 2, respectively. Both complexes catalytically oxidize 3,5‐di‐tert‐butylcatechol to 3,5‐di‐tert‐butylbenzoquinone in the presence of molecular oxygen.
Visible‐light‐driven photocatalytic degradation of fenpyroximate in rotating packed bed reactor using Fe3O4@PbS@Ni2P magnetic nanocomposite photocatalyst: Response surface modelling and optimization
Authors: Mosleh Soleiman , Rahimi Mahmood Reza , Ghaedi Mehrorang , Asfaram Arash , Javadian Hamedreza , Sadeghfar Fardin , Jannesar Ramin 
Published: July 2018

A highly efficient rotating packed bed photocatalytic reactor based on Fe3O4@PbS@Ni2P composite for the degradation of fenpyroximate (FP) as an acaricide in agriculture is described. The visible‐light‐driven photocatalyst was characterized using various techniques. The interaction of operational parameters consisting of rotational speed (400–1200 rpm), photocatalyst dosage (0.20–0.40 g l−1), solution flow rate (0.10–0.50 l min−1), aeration rate (15–35 l min−1), FP initial concentration (5–45 mg l−1), pH (2–10) and irradiation time (20–100 min) for FP degradation was examined via central composite design under response surface methodology. Accordingly, under the suggested optimum conditions, namely rotational speed of 950 rpm, Fe3O4@PbS@Ni2P dosage of 0.30 g l−1, solution flow rate of 0.30 l min−1, aeration rate of 25 l min−1, pH of 6.0 and irradiation time of 85 min, more than 99% of 45 mg l−1 FP was degraded. The Langmuir–Hinshelwood kinetic model was the best equation for the description of the experimental data. According to the rate constant, the contribution of photocatalytic degradation, adsorption and photolysis to the reduction of FP concentration and, subsequently, the efficiency of water treatment were studied.
Adaptive Robust Motion Control for Linear Induction Motor with Electromagnetic Nonlinearity Compensation
Authors: Lu Linlin , Sun Peng , Xu Linsen , Luo Minzhou 
Published: July 2018

AbstractThis paper presents an adaptive robust motion control algorithm for linear induction motor (LIM) with electromagnetic nonlinearity compensation to suppress nonlinear magnetic thrust reduction due to the end effect. The electromagnetic compensation adaptive robust control (ECARC) algorithm is developed to deal with the parametric uncertainties and uncertain nonlinearities that are widely present in LIM. This algorithm employs a discontinuous projection‐type method to estimate the system parameters. The disturbance is bounded by a critical value, which guarantees that the system is exponentially stable. However, due to the magnetic field distortion caused by the opening of primary ends, the relationship between the driving current and the resultant motor thrust is nonlinear. Consequently, electromagnetic thrust and flux are calculated and used for feedback compensation. Different from the traditional vector control and direct torque control, the control algorithm employs electromagnetic thrust and magnetic flux to compensate torque current and magnetic field. Simulation results and comparative experimental results show that current control algorithm is accurate and efficient.
Sulfur‐Doped Rhenium Selenide Vertical Nanosheets: A High‐Performance Electrocatalyst for Hydrogen Evolution
Authors: Xia Yufei , Huang Jianwen , Wu Wenqi , Zhang Yadong , Wang Hao , Zhu Juntong , Yao Junjie , Xu Li , Sun Yinghui , Zhang Li , Lu Ruifeng , Xiong Jie , Zou Guifu 
Published: July 2018

AbstractDeveloping highly efficient electrocatalysts for hydrogen generation from water has been a crucial option for future energy conversion and storage. Rhenium dichalcogenides (ReX2, X=S or Se) have attracted tremendous research interests due to their unique distorted‐1T phase and anisotropic electronic structure. So far, there is no report about S doped ReSe2 electrocatalyst. In this work, we present a three‐dimensional nanosheets electrocatalyst derived from sulfur‐doped rhenium selenide (ReSe2(1–x)S2x) grown on carbon fiber paper (CFP) for water splitting. It is noting that the catalytic activity could be significantly fine‐tuned by controlling quantity of sulfur dopant. ReSe1.78S0.22/CFP cathode exhibits the best performance with a Tafel slope of 84 mV dec−1, an overpotential of 123 mV to drive the current density of 10 mA cm−2 as well as a long‐term stability of 30 h. The X‐ray photoelectron spectroscopy and density functional theory calculations confirm that sulfur‐doped structure, especially the dangling sulfur atoms adsorbed on the surface Se atom kars, achieves a more thermoneutral hydrogen adsorption energy, conducing an optimized catalytic activity of the basal plane. This study demonstrates that S doped ReSe2 could be a promising candidate electrocatalyst for hydrogen evolution.
Interaction of Single Cells with 2D Organic Monolayers: A Scanning Electrochemical Microscopy Study
Authors: Bartolini Luca , Malferrari Marco , Lugli Francesca , Zerbetto Francesco , Paolucci Francesco , Pelicci Pier Giuseppe , Albonetti Cristiano , Rapino Stefania 
Published: July 2018

AbstractCell shape is a valuable indicator of cell health status and interactions with the extracellular materials. With the aim to investigate how individual cells respond to chemical microenvironments, we employed 2D monomolecular layers of small organic molecules, characterized by very low roughness. MCF10A cells were grown on these surfaces and characterized by using scanning electrochemical microscopy. The single cell morphologies were analyzed to define a “figure of merit” for the different cell–surface interactions. Such “figure of merit” quantifies the interaction with the microenvironment. This method is applicable to any cell state (metastatic, physiological or pathological) and any surface.
The Impedance Response of a Passive Film Revisited by a Double Modulation Technique
Authors: Antaño‐López René , Keddam Michel , Turmine Mireille , Vivier Vincent 
Published: July 2018

AbstractThe interfacial capacitance measured in electrochemical experiments is usually considered to be independent of the faradaic processes involved at the electrode surface. In this work, we report on the use of a double modulation technique, which allows the simultaneous measurement of electrochemical impedance spectroscopy (EIS) and modulation of the interfacial capacitance transfer function (MICTF). We show that the capacitance ascribed to the response of passive films formed on pure iron electrodes in phosphoric acid solution exhibits two different time‐constants in low frequency domains, namely the response of intrinsic properties of the film linked to charge carriers and a relaxation ascribed to the thickness relaxation of the oxide film. Interestingly, the low frequency limit of MICTF is in good agreement with the capacitance obtained from EIS measurements. A detailed data analysis allows determination of both, the capacitance of the oxide film and the double layer capacitance to the overall capacitance to be measured. This technique thus provides a unique way of analysing the different contributions ascribed to the relaxation of the interfacial capacitance.