bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Iridium‐Catalyzed ortho‐C—H Borylation of Aryl Ketones with Bis(pinacolato)diboron.
Authors: Itoh Hiroshi , Kikuchi Takao , Ishiyama Tatsuo , Miyaura Norio 
Published: January 2012

AbstractThe title reaction gives the compounds (III) in excellent regioselectivity.
ChemInform Abstract: Insertion of Benzynes into the P=N Bond of P‐Alkenyl(alkynyl)‐λ5‐phosphazenes.
Authors: Alajarin Mateo , Lopez‐Leonardo Carmen , Raja Rosalia , Orenes Raul‐Angel 
Published: January 2012

AbstractThe unsymmetrical methoxy derivative (XII) forms only one product since electronic factors dominate over steric ones.
ChemInform Abstract: Divergent Synthesis of 2,5‐Diarylphospholes Based on Cross‐Coupling Reactions: Substituent Effects on the Optical and Redox Properties of Benzene—Phosphole—Benzene π‐Systems.
Authors: Matano Yoshihiro , Kon Yusuke , Saito Arihiro , Kimura Yoshifumi , Murafuji Toshihiro , Imahori Hiroshi 
Published: January 2012

AbstractTwo kinds of Pd‐catalyzed cross‐coupling reactions are employed to synthesize diarylphospholes (III) and (VII) (Stille coupling), and (X) (Negishi coupling).
ChemInform Abstract: A New Hypoxia Inducible Factor‐2 Inhibitory Pyrrolinone Alkaloid from Roots and Stems of Piper sarmentosum.
Authors: Bokesch Heidi Rose , Gardella Roberta Scott , Rabe Daniel Christopher , Bottaro Donald Paul , Linehan William Marston , McMahon James Brislin , McKee Tawnya Carlene 
Published: January 2012

AbstractA new trimethoxycinnamoyl‐2‐pyrrolidinone alkaloid, named langkamide (I), is isolated along with two known trimethoxycinnamoyl derivatives from roots and stems of the pepper shrub Piper sarmentosum.
ChemInform Abstract: 3‐Hydroxydihydrobenzofuran Glucosides from Gnaphalium polycaulon.
Authors: Sahakitpichan Poolsak , Disadee Wannaporn , Ruchirawat Somsak , Kanchanapoom Tripetch 
Published: January 2012

AbstractThe new 3‐hydroxydihydrobenzofuran glucoside named gnaphaliol 9‐O‐β‐D‐glucopyranoside (I) is isolated from the aerial parts of Gnaphalium polycaulon together with 3 known compounds.
ChemInform Abstract: Pestalotheols E—H: Antimicrobial Metabolites from an Endophytic Fungus Isolated from the Tree Arbutus unedo.
Authors: Qin Song , Krohn Karsten , Hussain Hidayat , Schulz Barbara , Draeger Siegfried 
Published: January 2012

AbstractIsolation and structure elucidation of pestalotheols E (Ia), F (Ib), G (II) and H (III) is presented.
ChemInform Abstract: Hydrazidomycins, Cytotoxic Alkylhydrazides from Streptomyces atratus.
Authors: Ueberschaar Nico , Tchize Ndejouong Basile Le Sage , Ding Ling , Maier Armin , Fiebig Heinz‐Herbert , Hertweck Christian 
Published: January 2012

AbstractThree unusual alkylhydrazide natural products, named hydrazidomycin A (Ia), B (Ib), and C (Ic), are isolated from the chloroform extract of a Streptomyces atratus culture.
ChemInform Abstract: n‐Type Field‐Effect Transistors Based on Thieno[3,2‐b]thiophene‐2,5‐dione and the Bis(dicyanomethylene) Derivatives.
Authors: Chen Shiyan , Bolag Altan , Nishida Jun‐ichi , Yamashita Yoshiro 
Published: January 2012

AbstractThe optical (in CH2Cl2 solution and in solid films) and electronic properties and the field‐effect transistor performance of the thermally stable compounds (I) are investigated.
ChemInform Abstract: Exploration of Pyridine Containing Heteroaryl Analogues of Biaryl Ureas as DGAT1 Inhibitors.
Authors: Gupte Amol , et al. et al. 
Published: January 2012

Abstract2‐Pyridyl, e.g. (I), and 3‐pyridyl, e.g. (II), containing ureas are synthesized and evaluated as hDGAT1 inhibitors.
ChemInform Abstract: Discovery of BI 99179, a Potent and Selective Inhibitor of Type I Fatty Acid Synthase with Central Exposure.
Authors: Kley Joerg T. , Mack Juergen , Hamilton Bradford , Scheuerer Stefan , Redemann Norbert 
Published: January 2012

AbstractBased on a high‐throughput screening, cyclopentanecarboxanilides (I) are identified as a new chemotype of non‐covalent inhibitors of type 1 fatty acid synthase (FAS).
Bio‐heat transfer simulation of retinal laser irradiation
Authors: Narasimhan Arunn , Jha Kaushal Kumar 
Published: January 2012

SUMMARYRetinopathy is a surgical process in which maladies of the human eye are treated by laser irradiation. A two‐dimensional numerical model of the human eye geometry has been developed to investigate transient thermal effects due to laser radiation. In particular, the influence of choroidal pigmentation and that of choroidal blood convection—parameterized as a function of choroidal blood perfusion—are investigated in detail. The Pennes bio‐heat transfer equation is invoked as the governing equation, and finite volume formulation is employed in the numerical method. For a 500‐ μm diameter spot size, laser power of 0.2 W, and 100% absorption of laser radiation in the retinal pigmented epithelium (RPE) region, the peak RPE temperature is observed to be 103 °C at 100 ms of the transient simulation of the laser surgical period. Because of the participation of pigmented layer of choroid in laser absorption, peak temperature is reduced to 94 °C after 100 ms of the laser surgery period. The effect of choroidal blood perfusion on retinal cooling is found to be negligible during transient simulation of retinopathy. A truncated three‐dimensional model incorporating multiple laser irradiation of spots is also developed to observe the spatial effect of choroidal blood perfusion and choroidal pigmentation. For a circular array of seven uniformly distributed spots of identical diameter and laser power of 0.2 W, transient temperature evolution using simultaneous and sequential mode of laser surgical process is presented with analysis. Copyright © 2012 John Wiley & Sons, Ltd.
Classical Reactive Molecular Dynamics Implementations: State of the Art
Authors: Farah Karim , Müller‐Plathe Florian , Böhm Michael C. 
Published: January 2012

AbstractReactive molecular dynamics (RMD) implementations equipped with force field approaches to simulate both the time evolution as well as chemical reactions of a broad class of materials are reviewed herein. We subdivide the RMD approaches developed during the last decade as well as older ones already reviewed in 1995 by Srivastava and Garrison and in 2000 by Brenner into two classes. The methods in the first RMD class rely on the use of a reaction cutoff distance and employ a sudden transition from the educts to the products. Due to their simplicity these methods are well suited to generate equilibrated atomistic or material‐specific coarse‐grained polymer structures. In connection with generic models they offer useful qualitative insight into polymerization reactions. The methods in the second RMD class are based on empirical reactive force fields and implement a smooth and continuous transition from the educts to the products. In this RMD class, the reactive potentials are based on many‐body or bond‐order force fields as well as on empirical standard force fields, such as CHARMM, AMBER or MM3 that are modified to become reactive. The aim with the more sophisticated implementations of the second RMD class is the investigation of the reaction kinetics and mechanisms as well as the evaluation of transition state geometries. Pure or hybrid ab initio, density functional, semi‐empirical, molecular mechanics, and Monte Carlo methods for which no time evolution of the chemical systems is achieved are excluded from the present review. So are molecular dynamics techniques coupled with quantum chemical methods for the treatment of the reactive regions, such as Car–Parinello molecular dynamics.
Organic–Organic Heterostructures: Concepts and Applications
Authors: Hinderhofer Alexander , Schreiber Frank 
Published: January 2012

AbstractWe review basic concepts as well as recent examples and applications of organic–organic heterostructures. We organize the different types of heterostructures according to material A deposited on material B (A/B), A co‐deposited with B (A:B), heterostructures in the monolayer regime including nanostructuring concepts and systems involving self‐assembled monolayers, as well as various other architectures, including superlattices. While most examples are related to small‐molecule organic semiconductors, many of the ideas can be applied to other systems. The central theme is growth and structure as well as optical and electronic properties. Finally, we comment on implications for device applications.
Determination of Hydrogen‐Bond‐Accepting and ‐Donating Abilities of Ionic Liquids with Halogeno Complex Anions by Means of 1H NMR Spectroscopy
Authors: Lungwitz Ralf , Spange Stefan 
Published: January 2012

AbstractHydrogen‐bond‐accepting (HBA) and ‐donating (HBD) parameters of ionic liquids (ILs) with halogeno complex anions are determined by means of 1H NMR spectroscopy. Thereby, the imidazolium cation serves both as part of the IL and as 1H NMR probe. The HBA and HBD strength are calculated in terms of the empirical polarity parameters β and α according to the Kamlet–Taft equation. The study includes 1‐butyl‐3‐methylimidazolium ILs with chloroaluminates of various mole fractions from 0 to 0.67 of AlCl3, anions of the general chemical formula MtXn− (Mt=metal, X=halide) as well as tri‐ and pentaiodide. The 1H NMR chemical shift of the hydrogen atom in the two position of the imidazolium cation is a function of the HBA ability of the corresponding anion. For the chloroaluminates the HBA ability decreases and the HBD ability increases with increasing mole fraction of the Lewis acid. In general, the HBA strength of the studied ILs increases in the following order: MoCl6−<Al2Cl7−<AlCl4−<WCl7−<I5−<SnCl5−<I3−<SbCl6−<TiCl5−<BBr4−<SnCl3−. The corresponding HBD ability shows a reverse trend.
In Situ Observation of the Thermally Induced Growth of Platinum‐Nanoparticle Catalysts Using High‐Temperature X‐ray Diffraction
Authors: Hasché Frédéric , Oezaslan Mehtap , Strasser Peter 
Published: January 2012

AbstractFundamental understanding about the thermal stability of nanoparticles and deliberate control of structural and morphological changes under reactive conditions is of general importance for a wide range of reaction processes in heterogeneous and electrochemical catalysis. Herein, we present a parametric study of the thermal stability of carbon‐supported Pt nanoparticles at 80 °C and 160 °C, with an initial particle size below 3 nm, using in situ high‐temperature X‐ray diffraction (HT‐XRD). The effects on the thermal stability of carbon‐supported Pt nanoparticles are investigated with control parameters such as Brunauer–Emmet–Teller (BET) surface area, metal loading, temperature, and gas environment. We demonstrate that the growth rate exhibits a complex, nonlinear behavior and is largely controlled by the temperature, the initial particle size, and the interparticle distance. In addition, an ex situ transmission electron microscopy study was performed to verify our results obtained from the in situ HT‐XRD study.
Electron Transfer and Switching in Rigid [2]Rotaxanes Adsorbed on TiO2 Nanoparticles
Authors: Lestini Elena , Nikitin Kirill , Stolarczyk Jacek K. , Fitzmaurice Donald 
Published: January 2012

AbstractBistable [2]rotaxanes have been attached through a bulky tripodal linker to the surface of titanium dioxide nanoparticles and studied by cyclic voltammetry and spectroelectrochemical methods. The axle component in the [2]rotaxane contains two viologen sites, V1 and V2, interconnected by a rigid terphenylene bridge. In their parent dication states, V12+ and V22+ can both accommodate a crown ether ring, C, but are not equivalent in terms of their affinity towards C and have different electrochemical reduction potentials. The geometry and size of the tripodal linker help to maintain a perpendicular [2]rotaxane orientation at the surface and to avoid unwanted side‐to‐side interactions. When the rigid [2]rotaxane or its corresponding axle are adsorbed on a TiO2 nanoparticle, viologen V22+ is reduced at significantly more negative potentials (−0.3 V) than in flexible analogues that contain aliphatic bridges between V1 and V2. These overpotentials are analysed in terms of electron‐transfer rates and a donor–bridge–acceptor (D–B–A) formalism, in which D is the doubly reduced viologen, V10, adjacent to the TiO2 surface (TiO2–V10), B is the terphenylene bridge and A is viologen V22+. We have also found that, in contrast with earlier findings in solution, no molecular shuttling occurs in rigid [2]rotaxane adsorbed at the surface. The observations were explained by the relative position of the viologen stations within the electrical double layer, screening of V22+ by the counterions and high capacity of the medium, which reduces the mobility of the crown ether. The results are useful in transposing of solution‐based molecular switches to the interface or in the design and understanding of the properties of systems comprising electroactive and/or interlocked molecules adsorbed at the nanostructured TiO2 surface.
Homogeneous Photocatalytic Reactions with Organometallic and Coordination Compounds—Perspectives for Sustainable Chemistry
Authors: Hoffmann Norbert 
Published: January 2012

AbstractSince the time of Giacomo Ciamician at the beginning of the 20th century, photochemical transformations have been recognized as contributing to sustainable chemistry. Electronic excitation significantly changes the reactivity of chemical compounds. Thus, the application of activation reagents is frequently avoided and transformations can be performed under mild conditions. Catalysis plays a central role in sustainable chemistry. Stoichiometric amounts of activation reagents are often avoided. This fact and the milder catalytic reaction conditions diminish the formation of byproducts. In the case of homogeneous catalysis, organometallic compounds are often applied. The combination of both techniques develops synergistic effects in the sense of “Green Chemistry”. Herein, metal carbonyl‐mediated reactions are reported. These transformations are of considerable interest for the synthesis of complex polyfunctionalized compounds. Copper(I)‐catalyzed [2+2] photocycloaddition gives access to a large variety of cyclobutane derivatives. Currently, a large number of publications deal with photochemical electron‐transfer‐induced reactions with organometallic and coordination compounds, particularly with ruthenium complexes. Several photochemically induced oxidations can easily be performed with air or molecular oxygen when they are catalyzed with organometallic complexes. Photochemical reaction conditions also play a certain role in CH activation with organometallic catalysts, for instance, with alkanes, although such transformations are conveniently performed with a variety of other photochemical reactions.
Transfer of the Epoxidation of Soybean Oil from Batch to Flow Chemistry Guided by Cost and Environmental Issues
Authors: Kralisch Dana , Streckmann Ina , Ott Denise , Krtschil Ulich , Santacesaria Elio , Di Serio Martino , Russo Vincenzo , De Carlo Lucrezia , Linhart Walter , Christian Engelbert , Cortese Bruno , de Croon Mart H. J. M. , Hessel Volker 
Published: January 2012

AbstractThe simple transfer of established chemical production processes from batch to flow chemistry does not automatically result in more sustainable ones. Detailed process understanding and the motivation to scrutinize known process conditions are necessary factors for success. Although the focus is usually “only” on intensifying transport phenomena to operate under intrinsic kinetics, there is also a large intensification potential in chemistry under harsh conditions and in the specific design of flow processes. Such an understanding and proposed processes are required at an early stage of process design because decisions on the best‐suited tools and parameters required to convert green engineering concepts into practice—typically with little chance of substantial changes later—are made during this period. Herein, we present a holistic and interdisciplinary process design approach that combines the concept of novel process windows with process modeling, simulation, and simplified cost and lifecycle assessment for the deliberate development of a cost‐competitive and environmentally sustainable alternative to an existing production process for epoxidized soybean oil.
Hierarchical Hydroxyapatite Microspheres Composed of Nanorods and Their Competitive Sorption Behavior for Heavy Metal Ions
Authors: Zhu Ronghai , Lai Xiaoyong , Halpert Jonathan E. , Yu Ranbo , Wang Dan 
Published: January 2012

AbstractHydroxyapatite (HAP) microspheres composed of nanorods have successfully been prepared by a facile co‐precipitation method without any template. We propose the formation mechanism of the microspheres to be a four‐step process on the basis of the evolution of their morphology as a function of reaction time. We investigate the competitive sorption of the HAP microspheres for Pb2+, Cu2+, Cd2+, Zn2+, and Ni2+ to show that HAP microspheres are a highly selective adsorbent for Pb2+ in wastewater.
FeIII Spin‐Crossover Complexes with Photoisomerizable Ligands: Experimental and Theoretical Studies on the Ligand‐Driven Light‐Induced Spin Change Effect
Authors: Bannwarth Alexander , Schmidt Sven Olaf , Peters Gerhard , Sönnichsen Frank D. , Thimm Wulf , Herges Rainer , Tuczek Felix 
Published: January 2012

AbstractConflicting results have been reported with respect to the photoinduced switching of the magnetic properties of [FeIII(salten)]+ complexes [salten = 4‐azaheptamethylene‐1,7‐bis(salicylideneiminate)] coordinated by photoisomerizable ligands. In order to address this problem, two FeIII complexes [Fe(salten)(3‐azpy)]BPh4 (1) and [Fe(salten)(4‐azpy)]BPh4 (2) have been synthesized and characterized by various physicochemical methods (azpy = phenylazopyridine). Both 1 and 2 exhibit a low spin (S = 1/2) to high spin (HS, S = 5/2) transition in the solid state. In solution at room temperature both complexes are predominantly HS. Upon exposure to 310 (trans → cis) and 440 nm radiation (cis → trans) the free and coordinated 3‐ and 4‐azpy ligands undergo a reversible cis–trans isomerization. For 2 a corresponding reduction of the HS fraction 2 % is observed, whereas in 1 no effect is observed. Extensive DFT calculations, which employ different functionals and basis sets, explain this experimental result. The consequences of these findings with respect to the design of spin‐switchable iron(III) complexes with photoactive ligands are discussed.
Electroanalysis of Trace Inorganic Arsenic with Gold Nanoelectrode Ensembles
Authors: Mardegan A. , Scopece P. , Lamberti F. , Meneghetti M. , Moretto L. M. , Ugo P. 
Published: January 2012

AbstractThe results of a study on the determination of trace levels of arsenic with nanoelectrode ensembles (NEEs) are reported. In order to lower the detection limit and to increase the number of performable analysis for each NEE, the right choice of the supporting electrolyte concentration and electroanalytical parameters were optimized. The electrochemical behavior of As(III) at NEEs was studied at first by cyclic voltammetry, while trace concentrations of As(III) were determined by anodic stripping square wave voltammetry. The method is characterized by a detection limit as low as 5 ng/L (65 pM) after 3 min preconcentration at −0.4 V. Finally, NEEs were applied to trace As analysis in real samples such as certified seawater samples.
Voltammetric Determination of Clozapine in Pharmaceutical Formulations and Biological Fluids Using an In Situ Surfactant‐Modified Carbon Ionic Liquid Electrode
Authors: Arvand M. , Shiraz M. Ghasempour 
Published: January 2012

AbstractA carbon ionic liquid electrode modified in situ with sodium dodecylsulfate (SDS) was developed for the determination of clozapine (CLZ). These studies revealed that the oxidation of CLZ is facilitated at an in situ surfactant‐modified carbon ionic liquid electrode (ISS‐CILE). After optimization of analytical conditions, the peak currents for CLZ were found to vary linearly with its concentrations in the range of 1×10−9–1×10−7 mol L−1 with a slope of 2.18 µA/µmol L−1. The LOD and LOQ of the electrode were 2.08×10−10 mol L−1 and 6.95×10−10 mol L−1, respectively. The proposed method was employed for the determination of CLZ in pharmaceutical formulations, blood serum and plasma samples without any pretreatment steps.
Determination of Matrine Using a New Voltammetric Sensor Based on L‐Cysteine/Graphene Oxide‐Chitosan Composite Film Modified Electrode
Authors: Zhao Fangyuan , Wang Le , Liu Yanling , Song Ge , Wang Fei , Ye Baoxian 
Published: January 2012

AbstractA new voltammetric sensor for matrine was fabricated via the polymerization of L‐cysteine on graphene oxide, which served as templates. The fabricated electrode can improve the oxidation of matrine intensively, and enable the determination of matrine in the range from 4×10−6 to 1×10−4 mol L−1, with a detection limit of 2×10−6 mol L−1. The oxidation process of matrine was studied and some dynamic parameters were calculated using various electrochemical techniques. This present sensor displayed good stability, reproducibility and sensitivity for matrine. It was successfully applied to the quantitative determination of matrine in matrine injection with satisfactory results.
Electrochemical Performance of Self‐Assembled Monolayer Gold Nanoparticle‐Modified Ultramicroelectrode Array Architectures
Authors: Orozco Jahir , Jiménez‐Jorquera Cecilia , Fernández‐Sánchez César 
Published: January 2012

AbstractSurface architectures based on gold nanoparticles (AuNPs) electrodeposited on gold ultramicroelectrode arrays (UMEAs) and further modified with self‐assembled monolayers (SAMs) of two different thiol molecules were evaluated. The voltammetric behavior of the resulting electrochemical transducer approaches appeared to be fairly different compared to that of SAM‐modified UMEAs and microelectrode counterparts. Such behavior indicates that the electrodeposited AuNPs played a key role in the arrangement of the thiolated probes and the electron transfer processes at the transducer solution interface. A detailed description of this phenomenon was carried out with the aim of showing the potential of the presented SAM‐AuNP‐UMEA based transducer to develop robust biosensor approaches.
Proteomics of cypress pollen allergens using double and triple one‐dimensional electrophoresis
Authors: Shahali Youcef , Sutra Jean‐Pierre , Haddad Iman , Vinh Joëlle , Guilloux Laurence , Peltre Gabriel , Sénéchal Hélène , Poncet Pascal 
Published: January 2012

AbstractItalian cypress (Cupressus sempervirens, Cups) pollen causes allergic diseases in inhabitants of many of the cities surrounding the Mediterranean basin. However, allergens of Cups pollen are still poorly known. We introduce here a novel proteomic approach based on double one‐dimensional gel electrophoresis (D1‐DE) as an alternative to the 2‐DE immunoblot, for the specific IgE screening of allergenic proteins from pollen extracts. The sequential one‐dimensional combination of IEF and SDS‐PAGE associated with IgE immunoblotting allows a versatile multiplexed immunochemical analysis of selected groups of allergens by converting a single protein spot into an extended protein band. Moreover, the method appears to be valuable for MS/MS identification, without protein purification, of a new Cups pollen allergen at 43 kDa. D1‐DE immunoblotting revealed that the prevalence of IgE sensitization to this allergen belonging to the polygalacturonase (PG) family was 70% in tested French allergic patients. In subsequent triple one‐dimensional gel electrophoresis, the Cups pollen PG was shown to promote lectin‐based protein‐protein interactions. Therefore, D1‐DE could be used in routine work as a convenient alternative to 2‐DE immunoblotting for the simultaneous screening of allergenic components under identical experimental conditions, thereby saving considerable amounts of sera and allergen extracts.