bluuebunny/crossref_metadata_2025_split huggingface dataset:
Precisely Size‐Tunable Magnetic/Plasmonic Core/Shell Nanoparticles with Controlled Optical Properties
Authors: Yang Di , Pang Xinchang , He Yanjie , Wang Yiquan , Chen Genxiang , Wang Wenzhong , Lin Zhiqun 
Published: September 2015

AbstractStar‐like amphiphilic triblock copolymers were rationally designed and synthesized by combining two sequential atom‐transfer radical polymerization reactions with a click reaction. Subsequently, a family of uniform magnetic/plasmonic core/shell nanoparticles was crafted by capitalizing on these triblock copolymers as nanoreactors. The diameter of the magnetic core and the thickness of the plasmonic shell could be independently and accurately controlled by varying the molecular weights (i.e., the chain lengths) of the inner and intermediate blocks of the star‐like triblock copolymers, respectively. The surface plasmonic absorption of core/shell nanoparticles with different core diameters and shell thicknesses was systematically studied and theoretically modeled. This robust strategy provides easy access to a large variety of multifunctional nanoparticles with large lattice mismatches for use in optics, optoelectronics, catalysis, or bioimaging.
Kontrollierte lichtvermittelte Synthese von Gold‐Nanopartikeln über Norrish‐Typ‐I‐Reaktion in photoaktiven Polymeren
Authors: Mäsing Florian , Mardyukov Artur , Doerenkamp Carsten , Eckert Hellmut , Malkus Ursula , Nüsse Harald , Klingauf Jürgen , Studer Armido 
Published: September 2015

AbstractGold‐Nanopartikel (AuNPs) erfahren zurzeit aufgrund ihrer interessanten physikochemischen Eigenschaften große wissenschaftliche Beachtung. Wir stellen hier eine einfache und kontrollierte lichtvermittelte Synthese von Gold‐Nanopartikeln über Norrish‐Typ‐I‐Reaktion in photoaktiven Polymeren vor. Diese funktionell konzipierten Polymere agieren sowohl als Reagentien zur photochemischen Reduktion von Goldionen als auch zur Stabilisierung der in situ hergestellten AuNPs. Durch geschickte Variation der Länge und der Zusammensetzung der photoaktiven Polymere kann die Größe der Gold‐Nanopartikel in einem Bereich zwischen 1.5 nm und 9.6 nm gezielt eingestellt werden.
Readily Removable Directing Group Assisted Chemo‐ and Regioselective C(sp3)H Activation by Palladium Catalysis
Authors: Zhang Yun‐Fei , Zhao Hong‐Wei , Wang Hui , Wei Jiang‐Bo , Shi Zhang‐Jie 
Published: September 2015

AbstractCurrently used directing groups for selective aliphatic β‐functionalization of carbonyl compounds show excellent reactivity and selectivity with an amide as a linker. Described herein is 2‐piconimide, used for the first time with commercially available 2‐picolinamide/2‐picolic acid as precursors, to direct CH arylation/alkenylation by palladium catalysis. The directing group is essential for promoting the sequnetial primary and secondary C(sp3)H arylation with different aryl iodides in one substrate. The directing group was easily removed under simple reaction conditions at room temperature.
Highly Regioselective Radical Amination of Allenes: Direct Synthesis of Allenamides and Tetrasubstituted Alkenes
Authors: Zhang Ge , Xiong Tao , Wang Zining , Xu Guoxing , Wang Xuedan , Zhang Qian 
Published: September 2015

AbstractThe first controllable, regioselective radical amination of allenes with N‐fluoroarylsulfonimide is described to proceed under very mild reaction conditions. With this methodology, a general and straightforward route for the synthesis of both allenamides and fluorinated tetrasubstituted alkenes was realized from a wide range of terminal and internal allenes.
Rhodium‐Catalyzed Dehydrogenative Borylation of Aliphatic Terminal Alkenes with Pinacolborane
Authors: Morimoto Masao , Miura Tomoya , Murakami Masahiro 
Published: September 2015

AbstractAliphatic terminal alkenes react with pinacolborane at ambient temperature to afford dehydrogenative borylation compounds as the major product when iPr‐Foxap is used as the ligand with cationic rhodium(I) in the presence of norbornene, which acts as the sacrificial hydrogen acceptor. The reaction is applied to the one‐pot syntheses of aldehydes and homoallylic alcohols from aliphatic terminal alkenes.
Palladium‐Catalyzed Catellani ortho‐Acylation Reaction: An Efficient and Regiospecific Synthesis of Diaryl Ketones
Authors: Huang Yunze , Zhu Rui , Zhao Kun , Gu Zhenhua 
Published: September 2015

AbstractA palladium‐catalyzed, norbornene‐mediated Catellani ortho‐acylation reaction was developed by the use of either acyl chlorides or acid anhydrides as acylation reagents. The addition of more than a stoichiometric amount of H2O is crucial for this transformation when acid chlorides are used, and kinetic studies indicate that the active acylation reagent is possibly an acid anhydride.
The Triple‐Bond Metathesis of Aryldiazonium Salts: A Prospect for Dinitrogen Cleavage
Authors: Lackner Aaron D. , Fürstner Alois 
Published: September 2015

AbstractThe {N2} unit of aryldiazonium salts undergoes unusually facile triple‐bond metathesis on treatment with molybdenum or tungsten alkylidyne ate complexes endowed with triphenylsilanolate ligands. The reaction transforms the alkylidyne unit into a nitrile and the aryldiazonium entity into an imido ligand on the metal center, as unambiguously confirmed by X‐ray structure analysis of two representative examples. A tungsten nitride ate complex is shown to react analogously. Since the bonding situation of an aryldiazonium salt is similar to that of metal complexes with end‐on‐bound dinitrogen, in which {N2}→M σ donation is dominant and electron back donation minimal, the metathesis described herein is thought to be a conceptually novel strategy toward dinitrogen cleavage devoid of any redox steps and, therefore, orthogonal to the established methods.
Excited‐State Dynamic Planarization of Cyclic Oligothiophenes in the Vicinity of a Ring‐to‐Linear Excitonic Behavioral Turning Point
Authors: Park Kyu Hyung , Kim Pyosang , Kim Woojae , Shimizu Hideyuki , Han Minwoo , Sim Eunji , Iyoda Masahiko , Kim Dongho 
Published: September 2015

AbstractExcited‐state dynamic planarization processes play a crucial role in determining exciton size in cyclic systems, as reported for π‐conjugated linear oligomers. Herein, we report time‐resolved fluorescence spectra and molecular dynamics simulations of π‐conjugated cyclic oligothiophenes in which the number of subunits was chosen to show the size‐dependent dynamic planarization in the vicinity of a ring‐to‐linear behavioral turning point. Analyses on the evolution of the total fluorescence intensity and the ratio between 0–1 to 0–0 vibronic bands suggest that excitons formed in a cyclic oligothiophene composed of six subunits fully delocalize over the cyclic carbon backbone, whereas those formed in larger systems fail to achieve complete delocalization. With the aid of molecular dynamics simulations, it is shown that distorted structures unfavorable for efficient exciton delocalization are more easily populated as the size of the cyclic system increases.
Intramolecular Aminoboration of Unfunctionalized Olefins
Authors: Yang Chun‐Hua , Zhang Yu‐Shi , Fan Wen‐Wen , Liu Gong‐Qing , Li Yue‐Ming 
Published: September 2015

AbstractA direct and catalyst‐free method for the intramolecular aminoboration of unfunctionalized olefins is reported. In the presence of BCl3 (1 equiv) as the sole boron source, intramolecular aminoboration of sulfonamide derivatives of 4‐penten‐1‐amines, 5‐hexen‐1‐amines, and 2‐allylanilines proceeded readily without the use of any catalyst. The boronic acids obtained after hydrolysis could be converted into the corresponding pinacol borates in a straightforward manner by treatment with pinacol under anhydrous conditions.
Thermoelectricity Generation and Electron–Magnon Scattering in a Natural Chalcopyrite Mineral from a Deep‐Sea Hydrothermal Vent
Authors: Ang Ran , Khan Atta Ullah , Tsujii Naohito , Takai Ken , Nakamura Ryuhei , Mori Takao 
Published: September 2015

AbstractCurrent high‐performance thermoelectric materials require elaborate doping and synthesis procedures, particularly in regard to the artificial structure, and the underlying thermoelectric mechanisms are still poorly understood. Here, we report that a natural chalcopyrite mineral, Cu1+xFe1−xS2, obtained from a deep‐sea hydrothermal vent can directly generate thermoelectricity. The resistivity displayed an excellent semiconducting character, and a large thermoelectric power and high power factor were found in the low x region. Notably, electron–magnon scattering and a large effective mass was detected in this region, thus suggesting that the strong coupling of doped carriers and antiferromagnetic spins resulted in the natural enhancement of thermoelectric properties during mineralization reactions. The present findings demonstrate the feasibility of thermoelectric energy generation and electron/hole carrier modulation with natural materials that are abundant in the Earth’s crust.
The Instability of Ni{N(SiMe3)2}2: A Fifty Year Old Transition Metal Silylamide Mystery
Authors: Faust Michelle , Bryan Aimee M. , Mansikkamäki Akseli , Vasko Petra , Olmstead Marilyn M. , Tuononen Heikki M. , Grandjean Fernande , Long Gary J. , Power Philip P. 
Published: September 2015

AbstractThe characterization of the unstable NiIIbis(silylamide) Ni{N(SiMe3)2}2(1), its THF complex Ni{N(SiMe3)2}2(THF) (2), and the stable bis(pyridine) derivative trans‐Ni{N(SiMe3)2}2(py)2(3), is described. Both1and2decompose at ca. 25 °C to a tetrameric NiIspecies, [Ni{N(SiMe3)2}]4(4), also obtainable from LiN(SiMe3)2and NiCl2(DME). Experimental and computational data indicate that the instability of1is likely due to ease of reduction of NiIIto NiIand the stabilization of4through dispersion forces.
Shaped Ceria Nanocrystals Catalyze Efficient and Selective Para‐Hydrogen‐Enhanced Polarization
Authors: Zhao Evan W. , Zheng Haibin , Zhou Ronghui , Hagelin‐Weaver Helena E. , Bowers Clifford R. 
Published: September 2015

AbstractIntense para‐hydrogen‐enhanced NMR signals are observed in the hydrogenation of propene and propyne over ceria nanocubes, nano‐octahedra, and nanorods. The well‐defined ceria shapes, synthesized by a hydrothermal method, expose different crystalline facets with various oxygen vacancy densities, which are known to play a role in hydrogenation and oxidation catalysis. While the catalytic activity of the hydrogenation of propene over ceria is strongly facet‐dependent, the pairwise selectivity is low (2.4 % at 375 °C), which is consistent with stepwise H atom transfer, and it is the same for all three nanocrystal shapes. Selective semi‐hydrogenation of propyne over ceria nanocubes yields hyperpolarized propene with a similar pairwise selectivity of (2.7 % at 300 °C), indicating product formation predominantly by a non‐pairwise addition. Ceria is also shown to be an efficient pairwise replacement catalyst for propene.
Formation of Ruthenium Carbenes by gem‐Hydrogen Transfer to Internal Alkynes: Implications for Alkyne trans‐Hydrogenation
Authors: Leutzsch Markus , Wolf Larry M. , Gupta Puneet , Fuchs Michael , Thiel Walter , Farès Christophe , Fürstner Alois 
Published: September 2015

AbstractInsights into the mechanism of the unusual trans‐hydrogenation of internal alkynes catalyzed by {Cp*Ru} complexes were gained by para‐hydrogen (p‐H2) induced polarization (PHIP) transfer NMR spectroscopy. It was found that the productive trans‐reduction competes with a pathway in which both H atoms of H2 are delivered to a single alkyne C atom of the substrate while the second alkyne C atom is converted into a metal carbene. This “geminal hydrogenation” mode seems unprecedented; it was independently confirmed by the isolation and structural characterization of a ruthenium carbene complex stabilized by secondary inter‐ligand interactions. A detailed DFT study shows that the trans alkene and the carbene complex originate from a common metallacyclopropene intermediate. Furthermore, the computational analysis and the PHIP NMR data concur in that the metal carbene is the major gateway to olefin isomerization and over‐reduction, which frequently interfere with regular alkyne trans‐hydrogenation.
Manganese‐Catalyzed Oxidative Azidation of Cyclobutanols: Regiospecific Synthesis of Alkyl Azides by CC Bond Cleavage
Authors: Ren Rongguo , Zhao Huijun , Huan Leitao , Zhu Chen 
Published: September 2015

AbstractA novel, manganese‐catalyzed oxidative azidation of cyclobutanols is described. A wide range of primary, secondary, and tertiary alkyl azides were generated in synthetically useful yields and exclusive regioselectivity. Aside from linear alkyl azides, otherwise elusive medium‐sized cyclic azides were also readily prepared. Preliminary mechanistic studies reveal that the reaction likely proceeds by a radical‐mediated CC bond cleavage/CN3 bond formation pathway.
A Photoactive Carbon‐Monoxide‐Releasing Protein Cage for Dose‐Regulated Delivery in Living Cells
Authors: Fujita Kenta , Tanaka Yuya , Abe Satoshi , Ueno Takafumi 
Published: September 2015

AbstractProtein cages can serve as bioinorganic molecular templates for functionalizing metal compounds to regulate cellular signaling. We succeeded in developing a photoactive CO‐releasing system by constructing a composite of ferritin (Fr) containing manganese–carbonyl complexes. When Arg52 adjacent to Cys48 of Fr is replaced with Cys, the Fr mutant stabilizes the retention of 48 Mn–carbonyl moieties, which can release the CO ligands under light irradiation, although wild‐type Fr retains very few Mn moieties. The amount of released CO is regulated by the extent of irradiation. This could reveal an optimized dose for cooperatively activating the nuclear factor κB (NF‐κB) in mammalian cells and the tumor necrosis factor α (TNF‐α). These results suggest that construction of a CO‐releasing protein cage will advance of research in CO biology.
Al2O3 Nanosheets Rich in Pentacoordinate Al3+ Ions Stabilize Pt‐Sn Clusters for Propane Dehydrogenation
Authors: Shi Lei , Deng Gao‐Ming , Li Wen‐Cui , Miao Shu , Wang Qing‐Nan , Zhang Wei‐Ping , Lu An‐Hui 
Published: September 2015

AbstractIn heterogeneous catalysis, supports play a crucial role in modulating the geometric and electronic structure of the active metal phase for optimizing the catalytic performance. A γ‐Al2O3 nanosheet that contains 27 % pentacoordinate Al3+ sites can nicely disperse and stabilize raft‐like Pt‐Sn clusters as a result of strong interactions between metal and support. Consequently, there are strong electronic interactions between the Pt and Sn atoms, resulting in an increase in the electron density of the Pt sites. When used in the propane dehydrogenation reaction, this catalyst displayed an excellent specific activity for propylene formation with >99 % selectivity, and superior anti‐coking and anti‐sintering properties. Its exceptional ability to maintain the high activity and stability at ultrahigh space velocities further showed that the sheet construction of the catalyst facilitated the kinetic transfer process.
Effect of secondary air mass flow rate on the airflow and combustion characteristics and NOx formation of the low‐volatile coal‐fired swirl burner
Authors: Li Song , Li Zhengqi , Jiang Bingkun , Chen Zhichao , Zhang Xiqian 
Published: September 2015

AbstractLaboratory experiments and industrial‐scale experiments on 300‐MW low‐volatile coal‐fired boiler were performed under deep air staging. Aerodynamic characteristics, gas temperature and concentrations, furnace temperature, and boiler efficiency were measured for various secondary air mass flow rates. Under deep air staging, a steady central recirculation zone forms near the burner nozzle. With a decreasing flow rate, the swirl intensity and maximum axial, radial, and tangential velocities decrease; between X/D = 0–0.8, the velocity decay rate decreases, and the relative reverse flow rate decreases. In the early stage, the maximum axial mixing rate decreases; the primary air concentration increases slightly. A decrease in secondary air‐box damper opening decreases the gas temperature and its increasing rate, generating a farther ignition position. In the initial stage, the O2 consumption rate and CO concentration increase, while the NOx concentration decreases. In the later stage, O2 concentration remains almost constant below 2%, and the CO concentrations exceed 15 000 ppm, which restrain NOx formation notably. Near the water‐cooled wall, flue gas temperature varies slightly, and O2 concentration exceeds 3%. Along radial direction 1.5364 ≤ R0/D0 ≤ 1.8708, the O2 concentrations are below 2%, and CO concentrations exceed 6000 ppm. A decreasing damper opening decreases furnace temperature in the primary combustion zone slightly. NOx emission decreases from 833.4 to 769.9 mg/m3 (6% O2), unburnt carbon increases from 5.18% to 6.84%, and boiler efficiency decreases from 91.53% to 90.99%. Copyright © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Development of a cashew nut shell liquid (CNSL)‐based polymer for antibacterial activity
Authors: Kanehashi Shinji , Masuda Risa , Yokoyama Kota , Kanamoto Taisei , Nakashima Hideki , Miyakoshi Tetsuo 
Published: September 2015

ABSTRACTA biobased polymer derived from cashew nut shell liquid (CNSL) as a renewable resource was investigated for use as an antibacterial material. CNSL is a mixture of aromatics containing cardanol as the main component and cardol and 2‐methylcardol as minor components. CNSL composition analyses showed that the minor components (i.e., cardol and 2‐methylcardol) in CNSL had higher contents of unsaturated structures than cardanol. These higher unsaturated contents promoted the thermal polymerization in the preparation of an epoxy CNSL prepolymer (ECNP). The biobased polymer film was fabricated by the reaction of amine compounds and ECNP without any organic solvent. The ECNP film took less than 2.0 h to reach a hardened dry condition at room temperature because of the crosslinking reaction between epoxy and amine groups. The antibacterial activities of the biobased polymer against Escherichia coli and Staphylococcus aureus were evaluated. CNSL showed antibacterial activity against S. aureus, whereas epoxy CNSL and ECNP alone showed no significant antibacterial activity against E. coli or S. aureus. This indicated that the antibacterial activity was based on the phenolic and catechol hydroxyl groups of CNSL. In addition, a biobased polymer film derived from CNSL and diamine showed antibacterial activity against both E. coli and S. aureus, even with alcohol conditioning. This suggested that the antibacterial activity was certainly fixed in the structure of the ECNP‐based polymers after the standard antisepsis treatment in medical facilities. Therefore, this biobased polymer could be useful in antibacterial materials as a coating and resin for health care applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42725.
A carbazole–triphenylamine copolymer‐bearing pendant europium complexes: Synthesis and luminescence properties
Authors: Jin Yuxia , Zuo Weiwei , Gao Hongyan , Fu Linfeng , Liu Yingliang , Wu Wenbo , Xu Shengang , Cao Shaokui 
Published: September 2015

ABSTRACTA novel carbazole–triphenylamine copolymer‐bearing pendant bipyridine PM1TPA and corresponding europium (III) complexed polymer PM1TPA–Eu–x, in which the values of x are 0.1, 0.5, and 1.0 representing the molar ratio of bipyridine ligands complexed with Eu(III), were designed and synthesized. Their chemical structures were confirmed by 1H NMR, FT‐IR, and elemental analysis. Both PM1TPA and PM1TPA–Eu shows good solubility in common organic solvents such as tetrahydrofuran (THF) and CHCl3. The 5% weight loss temperature (Td5%) of PM1TPA and PM1TPA–Eu–1.0 are 363oC and 306oC, respectively. The photoluminescence (PL) spectra of PM1TPA–Eu in solution consists of two emission bands, one in the 400–570 nm region and another at 612 nm, corresponding to the emission of polymer main chain and europium complexes, respectively. When the concentration of PM1TPA–Eu–1.0 in THF solution increases, the PL intensity in the 400–570 nm regions became more and more weaker. And only the characteristic emission of europium complex was observed in the solid film, which indicates that the excited energy absorbed by the polymer backbone was efficiently transferred to the europium complexes. Furthermore, nearly monochromatic red electroluminescence from europium complex was observed from the polymeric light‐emitting diode using PM1TPA–Eu–1.0 as the emissive layer under 25 V forward bias. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42746.
Mechanical and thermal properties of poly(butylene succinate)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) biodegradable blends
Authors: Phua Y. J. , Pegoretti A. , Araujo T. Medeiros , Ishak Z. A. Mohd 
Published: September 2015

ABSTRACTBiodegradable polymer blends of poly(butylene succinate) (PBS) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) were prepared with different compositions. The mechanical properties of the blends were studied through tensile testing and dynamic mechanical thermal analysis. The dependence of the elastic modulus and strength data on the blend composition was modeled on the basis of the equivalent box model. The fitting parameters indicated complete immiscibility between PBS and PHBV and a moderate adhesion level between them. The immiscibility of the parent phases was also evidenced by scanning electron observation of the prepared blends. The thermal properties of the blends were studied through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results showed an enhancement of the crystallization behavior of PBS after it was blended with PHBV, whereas the thermal stability of PBS was reduced in the blends, as shown by the TGA thermograms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42815.
Urea‐activated 4,4'‐oxibis‐(benzenesulfonyl hydrazide) as foaming agent for low‐density unsaturated polyester resin manufacturing
Authors: Zhang Yi‐Fan , Wang Xiao‐Jun , Pan Zhi‐Gang , Hong Cheng‐Ming , Ji Gao‐Feng 
Published: September 2015

ABSTRACTThe activation of foaming agent is critical to its application. In this study, 4,4′‐oxibis‐(benzenesulfonyl hydrazide) (OBSH) activated by urea was used in the manufacture of low‐density unsaturated polyester resin (LDUPR), and the results were compared with that of OBSH activated by zinc oxide and zinc stearate. The experiment results showed that the activation of OBSH by urea was better than by zinc oxide or by zinc stearate. A novel hydrogen bond activation mechanism of urea is presented in this research. Two stages, including the induction stage and the foaming stage, were proposed in the LDUPR manufacture according to the gas evolution curves of activated OBSH. The decomposition temperature and the decomposition time of OBSH activated by urea were determined to match the gelation time of UPR for the manufacture of LDUPR. The disadvantageous chemical behaviors of activated OBSH were eliminated in the induction treatment. The activated OBSH via induction treatment released gas maximally and distributed gas homogeneously in the resin glue, resulting in a better foaming effect than that of the previous foaming agents. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42824.