bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Priori Estimation of Organic Reaction Yields
Authors: Emami Fateme S. , Vahid Amir , Wylie Elizabeth K. , Szymkuć Sara , Dittwald Piotr , Molga Karol , Grzybowski Bartosz A. 
Published: July 2015

AbstractA thermodynamically guided calculation of free energies of substrate and product molecules allows for the estimation of the yields of organic reactions. The non‐ideality of the system and the solvent effects are taken into account through the activity coefficients calculated at the molecular level by perturbed‐chain statistical associating fluid theory (PC‐SAFT). The model is iteratively trained using a diverse set of reactions with yields that have been reported previously. This trained model can then estimate a priori the yields of reactions not included in the training set with an accuracy of ca. ±15 %. This ability has the potential to translate into significant economic savings through the selection and then execution of only those reactions that can proceed in good yields.
Dialkyl Ether Formation by Nickel‐Catalyzed Cross‐Coupling of Acetals and Aryl Iodides
Authors: Arendt Kevin M. , Doyle Abigail G. 
Published: July 2015

AbstractA new substrate class for nickel‐catalyzed C(sp3) cross‐coupling reactions is reported. α‐Oxy radicals generated from benzylic acetals, TMSCl, and a mild reductant can participate in chemoselective cross‐coupling with aryl iodides using a 2,6‐bis(N‐pyrazolyl)pyridine (bpp)/Ni catalyst. The mild, base‐free conditions are tolerant of a variety of functional groups on both partners, thus representing an attractive CC bond‐forming approach to dialkyl ether synthesis. Characterization of a [(bpp)NiCl] complex relevant to the proposed catalytic cycle is also described.
Catalytic Silylations of Alcohols: Turning Simple Protecting‐Group Strategies into Powerful Enantioselective Synthetic Methods
Authors: Xu Li‐Wen , Chen Yun , Lu Yixin 
Published: July 2015

AbstractIn recent years, remarkable progress has been made in the enantioselective silylation of alcohols. Owing to the successful site‐ and stereoselective functionalization of hydroxy groups, silyl ether formations have evolved from being a simple reaction for functional‐group protection into a powerful enantioselective process. In this Minireview, we highlight important recent findings in this emerging field.
Chemical Detoxification of Organomercurials
Authors: Banerjee Mainak , Karri Ramesh , Rawat Kuber Singh , Muthuvel Karthick , Pathak Biswarup , Roy Gouriprasanna 
Published: July 2015

AbstractOrganomercurials including methylmercury are ubiquitous environmental pollutants and highly toxic to humans. Now it could be shown that N‐methylimidazole based thiones/selones having an N‐CH2CH2OH substituent are remarkably effective in detoxifying various organomercurials to produce less toxic HgE (E=S, Se) nanoparticles. Compounds lacking the N‐CH2CH2OH substituent failed to produce HgE nanoparticles upon treatment with organomercurials, suggesting that this moiety plays a crucial role in the detoxification by facilitating the desulfurization and deselenization processes. This novel way of detoxifying organomercurials may lead to the discovery of new compounds to treat patients suffering from methylmercury poisoning.
Finding the Most Catalytically Active Platinum Clusters With Low Atomicity
Authors: Imaoka Takane , Kitazawa Hirokazu , Chun Wang‐Jae , Yamamoto Kimihisa 
Published: July 2015

AbstractOn a subnanometer scale, an only one‐atom difference in a metal cluster may cause significant transitions in the catalytic activity due to the electronic and geometric configurations. We now report the atomicity‐specific catalytic activity of platinum clusters with significantly small atomicity, especially below 20. The atomic coordination structure is completely different from that of the larger face‐centered cubic (fcc) nanocrystals. Here, an electrochemical study on such small clusters, in which the atomicity ranged between 12 and 20, revealed Pt19 as the most catalytically active species. In combination with a theoretical study, a common structure that leads to a high catalytic performance is proposed.
Encapsulating Inorganic Acetylene, HBNH, Using Flanking Coordinative Interactions
Authors: Swarnakar Anindya K. , Hering‐Junghans Christian , Nagata Koichi , Ferguson Michael J. , McDonald Robert , Tokitoh Norihiro , Rivard Eric 
Published: July 2015

AbstractA stable donor–acceptor coordination complex of the elusive parent inorganic iminoborane HBNH (a structural analogue of acetylene) is reported. This species was generated via thermally induced N2 elimination/1,2‐H migration from a hydrido(azido)borane adduct NHC⋅BH2N3 (NHC=N‐heterocyclic carbene) in the presence of a fluorinated triarylborane. The mechanism of this process was also investigated by computational and isotopic labeling studies. This transformation represents a new and potentially modular route to unsaturated inorganic building blocks for advanced material synthesis.
A Graphitic‐C3N4 “Seaweed” Architecture for Enhanced Hydrogen Evolution
Authors: Han Qing , Wang Bing , Zhao Yang , Hu Chuangang , Qu Liangti 
Published: July 2015

AbstractA seaweed‐like graphitic‐C3N4 (g‐C3N4 “seaweed”) architecture has been prepared by direct calcination of the freeze‐drying‐assembled, hydrothermally treated dicyandiamide fiber network. The seaweed network of mesoporous g‐C3N4 nanofibers is favorable for light harvesting, charge separation and utilization of active sites, and has highly efficient photocatalytic behavior for water splitting. It exhibits a high hydrogen‐evolution rate of 9900 μmol h−1 g−1 (thirty times higher than that of its g‐C3N4 bulk counterpart), and a remarkable apparent quantum efficiency of 7.8 % at 420 nm, better than most of the g‐C3N4 nanostructures reported. This work presents a very simple method for designing and developing high‐performance catalysts for hydrogen evolution.
Dissolution Engineering of Platinum Alloy Counter Electrodes in Dye‐Sensitized Solar Cells
Authors: Tang Qunwei , Zhang Huihui , Meng Yuanyuan , He Benlin , Yu Liangmin 
Published: July 2015

AbstractThe dissolution of platinum (Pt) has been one of the heart issues in developing advanced dye‐sensitized solar cells (DSSCs). We present here the experimental realization of stable counter‐electrode (CE) electrocatalysts by alloying Pt with transition metals for enhanced dissolution resistance to state‐of‐the‐art iodide/triiodide (I−/I3−) redox electrolyte. Our focus is placed on the systematic studies of dissolution engineering for PtM0.05 (M=Ni, Co, Fe, Pd, Mo, Cu, Cr, and Au) alloy CE electrocatalysts along with mechanism analysis from thermodynamical aspects, yielding more negative Gibbs free energies for the dissolution reactions of transition metals. The competitive reactions between transition metals with iodide species (I3−, I2) could protect the Pt atoms from being dissolved by redox electrolyte and therefore remain the high catalytic activity of the Pt electrode.
Poplar wood–methylol urea composites prepared by in situ polymerization. II. Characterization of the mechanism of wood modification by methylol urea
Authors: Lang Qian , Bi Zeng , Pu Jun‐Wen 
Published: July 2015

ABSTRACTA prepolymer was used to prepare wood/prepolymer composites by a pulse‐dipping machine. The mechanical properties and dimensional stability were evaluated. The characterization of natural and modified woods was performed by Fourier transform infrared spectroscopy, 13C‐NMR spectroscopy, X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) with energy‐dispersive X‐ray analysis (EDXA). Cross‐polarization/magic‐angle spinning 13C‐NMR analysis revealed that the in situ polymerization between the prepolymer and the hydroxyls in the wood structure took place with the reduction of hydroxyl groups. XPS analysis indicated that the content of carbon decreased, whereas the content of oxygen increased. SEM–EDXA indicated a good dispersion of the modifier in the wood fiber and other vertical cells. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42406.
Preparation, characterization, and antibacterial activities of quaternarizedN‐halamine‐grafted cellulose fibers
Authors: Chen Xiaoqin , Liu Zuliang , Cao Weiwei , Yong Chunyan , Xing Xiaodong 
Published: July 2015

ABSTRACTA viable method for coating of cellulose fiber with quaternarized N‐halamine is reported in this article. The use of quaternary ammonium salt group in combination with N‐halamine group can reinforce the antibacterial activity. The chemical structure of as‐synthesized N‐halamine precursor 4‐(Bromo‐acetic acid methylester)‐4‐ethyl‐2‐ oxazolidinone (BEO) was characterized by1H‐NMR. The cellulose fibers were characterized by Fourier transform infrared spectra and X‐ray photoelectron spectra. The spectra data confirmed that the quaternarized N‐halamine‐grafted cellulose fibers were successfully obtained. The antibacterial properties of functional fibers were challenged with both Gram positive and Gram negative bacteria. The antibacterial tests and showed that the as‐prepared antibacterial cellulose fibers exhibited powerful and rapid bactericidal performance against both Gram negativeE. coliand Gram positiveS. aureus. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42702.
Tsuji–Wacker Oxidation of Terminal Olefins using a Palladium–Carbon Nanotube Nanohybrid
Authors: Donck Simon , Gravel Edmond , Shah Nimesh , Jawale Dhanaji V. , Doris Eric , Namboothiri Irishi N. N. 
Published: July 2015

AbstractPalladium nanoparticles supported on carbon nanotubes were used in the Tsuji–Wacker oxidation. The palladium‐based nanohybrid was found to be very active in combination with cuprous chloride for the selective oxidation of terminal olefins into methyl ketones. The co‐catalytic system operates under very mild and sustainable conditions (room temperature, atmospheric pressure, low catalyst loading), as opposed to previously reported catalysts, and can be recycled without any loss in activity.
One‐Pot Synthesis of a Nitrogen‐Doped Carbon Composite by Electrospinning as a Metal‐Free Catalyst for Oxidation of H2S to Sulfur
Authors: Liu Yuefeng , Duong‐Viet Cuong , Luo Jingjie , Hébraud Anne , Schlatter Guy , Ersen Ovidiu , Nhut Jean‐Mario , Pham‐Huu Cuong 
Published: July 2015

AbstractA macroscopic composite consisting of nitrogen‐doped carbon fibers (N@CFs) was synthesized by electrospinning. The as‐prepared N@CF material was further applied as a metal‐free catalyst in the catalytic oxidation of H2S to sulfur, which is one of the most important purification processes for raw chemical resources (that is, biogas, natural gas, and petrochemical compounds). The catalyst, after a carbonization step at T=800 °C, exhibits a high and stable desulfurization activity for more than 100 h of testing with 57 % H2S conversion and 95 % sulfur selectivity at T=230 °C, which is two times higher than that of the most active metal‐based catalyst (Fe2O3/SiC). The desulfurization performance could also be improved by changing the reactant velocity. Moreover, the macroscopic shaping with an inner hierarchical structure network allows the avoidance of problems linked with the transport and handling of nanoscopic carbon‐based materials and also enhances the mass diffusion during the oxidation reaction.
Engineering Nanoporous Iron(III) Oxide into an Effective Water Oxidation Electrode
Authors: Haschke Sandra , Wu Yanlin , Bashouti Muhammad , Christiansen Silke , Bachmann Julien 
Published: July 2015

AbstractThe geometric effects of nanostructuring a pure Fe2O3 surface on its electrochemical water oxidation performance at neutral pH were systematically explored. Atomic layer deposition was used to coat the inner walls of cylindrical “anodic” nanopores ordered in parallel arrays with a homogeneous Fe2O3 layer. Annealing and electrochemical treatments generated a roughened surface, as demonstrated by X‐ray photoelectron spectroscopy and electrochemical impedance spectroscopy, the larger geometric area of which increases current densities. Combining these treatments with the “anodic” pore geometry delivered an effective increase in turnover by almost three orders of magnitude with respect to a smooth, planar Fe2O3 surface. However, the current density depended on the pore length in a non‐monotonic manner. An optimal length was found that maximized turnover by equating the rate of transport in the electrolyte with that of charge transfer across the interface.
Silica‐Grafted SnIV Catalysts in Hydrogen‐Transfer Reactions
Authors: Conrad Sabrina , Verel René , Hammond Ceri , Wolf Patrick , Göltl Florian , Hermans Ive 
Published: July 2015

AbstractSnIV‐substituted zeolites show remarkable activity for important Lewis acid catalyzed reactions. In such complex catalytic systems it is, however, difficult to untangle the influence of all parameters contributing to the overall performance, and hence to rationally improve the catalyst. In this work, we studied silica‐grafted SnIV sites to reduce this complexity by eliminating the potential influence of pore confinement. The surface‐anchored SnIV sites were modified by calcination and silylation to increase Lewis acidity and hydrophobicity. Various techniques were used to characterize the materials, including the adsorption of cyclohexanone by using FTIR spectroscopy. We relate our spectroscopic results with catalytic tests and compare our model catalysts with benchmark Snβ zeolite. This suggested that besides active‐site structure, also hydrophobicity and confinement effects influence the activity. Our work demonstrates the utility of model systems to separate the different contributions to catalytic activity.
Hierarchically Porous and Nitrogen‐Doped Graphene‐Like Microspheres as Stable Anodes for Lithium‐Ion Batteries
Authors: Sun Dongfei , Yan Xingbin , Yang Juan , Zhang Peng , Xue Qunji 
Published: July 2015

AbstractNovel 3D hierarchically porous and nitrogen‐doped graphene‐like microspheres (3D NPGSs) are prepared by precursor‐assisted chemical vapor deposition. 3D NPGSs obtained by using Ni microspheres as a structural template exhibit a 3D conductive framework, and have a well‐defined porous structure, large surface area and appropriate heteroatom doping, making them suitable for high‐performance storage of lithium ions. Consequently, a good rate capability and excellent cycle performance are achieved using the 3D NPGSs as anodes for lithium storage, and a high reversible capacity of 840 mA h g−1 is obtained after 200 cycles. For a further capacitance boost, a thin layer of iron oxide nanoparticles is deposited onto the 3D NPGSs. The resulting 3D FeOx–NPGS electrode exhibits a stable reversible capacity up to 1343 mA h g−1 after 100 cycles.
Synthesis of Integrated Layered‐Spinel Composite Cathode Materials for High‐Voltage Lithium‐Ion Batteries up to 5.0 V
Authors: Zhao Jianqing , Ellis Sarah , Xie Zhiqiang , Wang Ying 
Published: July 2015

AbstractIntegrated layered‐spinel composite materials are synthesized through the facile decomposition of Li4Mn5O12‐based spinel materials at 900 °C. The intergrowth of spinel Li1+zMn2−zO4 (0<z<0.33) and Li‐rich layered Li2MnO3 components is examined by using X‐ray diffraction and high‐resolution transmission electron microscopy. Such a layered‐spinel composite material and its derivatives obtained by doping transition‐metal ions are evaluated as high‐voltage cathode materials for advanced lithium‐ion batteries up to 5.0 V versus Li/Li+. The Ni‐doped composite cathode shows remarkably high‐energy and high‐power characteristics with high‐voltage plateaus at approximately 4.7 V, delivering desirable discharge capacities of 130, 115, and 90 mAh g−1 at current densities of 25, 125, and 500 mA g−1, respectively, along with excellent cycling stability. This work provides a facile route for preparing the integrated layered‐spinel composite materials as promising high‐voltage cathode materials for lithium‐ion batteries.
Effect of Additives on the Low‐Temperature Stability of Vanadium Redox Flow Battery Negative Half‐Cell Electrolyte
Authors: Mousa Asem , Skyllas‐Kazacos Maria 
Published: July 2015

AbstractAn extensive screening of additives was undertaken to identify precipitation inhibitors to reduce the lower temperature limit of the negative half‐cell electrolyte of the vanadium redox battery. In contrast to the 2 m VII blank solution that precipitated within 16 h at 5.0 °C, in a supporting electrolyte of sulfuric acid with 5 m total sulfates, the induction time for precipitation was more than 46 h in the presence of ammonium phosphate, ammonium sulfate, Flucon‐100, sodium pentapolyphosphate and glycerol. In the case of the 2 m VIII solutions, considerable precipitation was observed after 4 days with 6.5 m total sulfates and the induction time increased to more than 40 days in the presence of ammonium phosphate, ammonium sulfate, sodium pentapolyphosphate and Orotan 1124. Cell cycling experiments confirmed that ammonium phosphate can dramatically extend the cell operation of a 2 m vanadium solution without precipitation over more than 250 cycles at 5 °C, compared with less than 15 cycles for a blank solution without additives.
Synthesis of Globular Precursors
Authors: Teixidor Francesc , Sillanpää Reijo , Pepiol Ariadna , Lupu Marius , Viñas Clara 
Published: July 2015

Abstracto‐Carborane (C2B10H12) was adapted to perform as the core of globular macromolecules, dendrons or dendrimers. To meet this objective, precisely defined substitution patterns of terminal olefin groups on the carborane framework were subjected to Heck cross‐coupling reactions or hydroboration leading to hydroxyl terminated arms. These led to new terminal groups (chloro, bromo, and tosyl leaving groups, organic acid, and azide) that permitted ester production, click chemistry, and oxonium ring opening to be performed as examples of reactions that demonstrate the wide possibilities of the globular icosahedral carboranes to produce new dendritic or dendrimer‐like structures. Polyanionic species were obtained in high yield through the ring‐opening reaction of cyclic oxonium compound [3,3′‐Co(8‐C4H8O2‐1,2‐C2B9H10)(1′,2′‐C2B9H11)] by using terminal hydroxyl groups as nucleophiles. These new polyanionic compounds that contain multiple metallacarborane clusters at their periphery may prove useful as new classes of compounds for boron neutron capture therapy with enhanced water solubility and as cores to make a new class of high‐boron globular macromolecules.
Coordination‐Driven Self‐Assembly of Carbazole‐Based Metallodendrimers with Generation‐Dependent Aggregation‐Induced Emission Behavior
Authors: Fan Wen‐Jia , Sun Bin , Ma Jianqiu , Li Xiaopeng , Tan Hongwei , Xu Lin 
Published: July 2015

AbstractA new family of 120° carbazole‐based dendritic donors D1–D3 have been successfully designed and synthesized, from which a series of novel supramolecular carbazole‐based metallodendrimers with well‐defined shapes and sizes were successfully prepared by [2+2] and [3+3] coordination‐driven self‐assembly. The structures of newly designed rhomboidal and hexagonal metallodendrimers were characterized by multinuclear NMR (1H and 31P) spectroscopy, ESI‐TOF mass spectrometry, FTIR spectroscopy, and the PM6 semiempirical molecular orbital method. The fluorescence emission behavior of ligands D1–D3, rhomboidal metallodendrimers R1–R3, and hexagonal metallodendrimers H1–H3 in mixtures of dichloromethane and n‐hexane with different n‐hexane fractions were investigated. The results indicated that D1–D3 featured typical aggregation‐induced emission (AIE) properties. However, different from ligands D1–D3, metallodendrimers R1–R3 and H1–H3 presented interesting generation‐dependent AIE properties. Furthermore, evidence for the aggregation of these metallodendrimers was confirmed by a detailed investigation of dynamic light‐scattering, Tyndall effect, and SEM. This research not only provides a highly efficient strategy for constructing carbazole‐based dendrimers with well‐defined shapes and sizes, but also presents a new family of carbazole‐based dendritic ligands and rhomboidal and hexagonal metallodendrimers with interesting AIE properties.
Synthesis of Phenanthrene Derivatives by Intramolecular Cyclization Utilizing the [1,2]‐Phospha‐Brook Rearrangement Catalyzed by a Brønsted Base
Authors: Kondoh Azusa , Aoki Takuma , Terada Masahiro 
Published: July 2015

AbstractThe synthesis of functionalized phenanthrene derivatives was achieved by intramolecular cyclization utilizing the [1,2]‐phospha‐Brook rearrangement under Brønsted base catalysis. Treatment of biaryl compounds having an α‐ketoester moiety and an alkyne moiety at the 2 and 2′ positions, respectively, with diisopropyl phosphite in the presence of a catalytic amount of phosphazene base P2‐tBu provides 9,10‐disubstituted phenanthrene derivatives in high yields. This reaction involves the generation of an ester enolate through an umpolung process, that is, addition of diisopropyl phosphite to a keto moiety followed by the [1,2]‐phospha‐Brook rearrangement, the intramolecular addition to an alkyne, and the [3,3] rearrangement of the allylic phosphate moiety in a consecutive fashion.
An Oxofluoride Catalyst Comprised of Transition Metals and a Metalloid for Application in Water Oxidation
Authors: Svengren Henrik , Hu Shichao , Athanassiadis Ioannis , Laine Tanja M. , Johnsson Mats 
Published: July 2015

AbstractThe application of the recently discovered oxofluoride solid solution (CoxNi1−x)3Sb4O6F6 as a catalyst for water oxidation is demonstrated. The phase exhibits a cubic arrangement of the active metal that forms oxo bridges to the metalloid with possible catalytic participation. The Co3Sb4O6F6 compound proved to be capable of catalyzing 2H2O→O2+4H++4e− at 0.33 V electrochemical and ≤0.39 V chemical overpotential with a TOF of 4.4⋅10−3, whereas Ni3Sb4O6F6 needs a higher overpotential. Relatively large crystal cubes (0.3–0.5 mm) are easily synthesized and readily handled as they demonstrate both chemical resistance to wear after repeated in situ tests under experimental conditions, and have a mechanical hardness of 270 V0.1 using Vickers indentation. The combined properties of this compound offer a potential technical advantage for incorporation to a catalytic interface in future sustainable fuel production.
Dynamic Ligand Reactivity in a Rhodium Pincer Complex
Authors: Tang Zhou , Otten Edwin , Reek Joost N. H. , van der Vlugt Jarl Ivar , de Bruin Bas 
Published: July 2015

AbstractLigand cooperativity provides (transition) metal complexes with new reactivities in substrate activation and catalytic reactions, but usually the ligand acts as an internal (Brønsted) base, while the metal acts as a (Lewis) acid. We describe the synthesis and stepwise activation of a new phosphane‐pyridine‐amide ligand PNNH2 in combination with RhI. The ligand is susceptible to stepwise proton and hydride loss from the nitrogen arm (imine formation) and deprotonation at the pyridylphosphine arm (dearomatization), giving rise to amine complex 1, amido species 2, imine complex 3 and dearomatized compound 4. Complex 4 bears a dual‐mode cooperative PNN′ ligand containing both a (nucleophilic) basic methine fragment and a reactive (electrophilic) imine moiety. The basic ligand arm enables substrate deprotonation while the imine ligand arm enables reversible “storage” of the activated (nucleophilic) form of a sulfonamide substrate at the ligand. In combination with metal‐based reactivity, this allows for the mono‐alkylation of o‐toluenesulfonamide with iodomethane. Compounds 1, 3 and 4 are structurally characterized. We also report the first structurally characterized example of an aminal in the coordination sphere of rhodium, complex 5, [Rh(CO)(PNN′′)], formed by sequential NH activation of sulfonamide by the dearomatized ligand PNN′ and follow‐up nucleophilic attack of anionic sulfonamide onto the imine fragment.