bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of PbS nanoparticles in block copolymer micelles
Authors: Schneider T. , Haase M. , Kornowski A. , Naused S. , Weller H. , Förster S. , Antonietti M.
Published: July 2012

Precipitation of lead ions by hydrogen sulfide in the presence of amphiphilic block copoloymer micelles composed of polystyrene‐b‐poly(4)vinylpridine yields PbS nanoparticles. By adjusting the reaction conditions with respect to the lead‐to‐polymer ratio, temperature or proton concentration particles of different size (2 to 20 nm) and morphology (spheres, cubes or needles) have been prepared. These particles have been characterized by powder X‐ray diffraction and High Resolution Transmission Electron Microscopy (HRTEM).

At a low lead content of the polymer micelles and relevated temperatures the formation of nanocrystalline PbS needles is preferred. These exhibit a structured absorption spectrum with two peaks at 375 and 580 nm. In polymer micelles with high lead content, PbS spheres (1 to 2 nm) are formed. Growth of these particles can be induced by increasing the proton concentration, resulting in particles with diameters up to 20 nm.
Physico‐chemical properties of crystalline nanoscale enzyme‐protein‐metal layer composites in biosensors
Authors: Pum Dietmar , Neubauer Angela , Sleytr Uwe B. , Pentzien Simone , Reetz Susanne , Kautek Wolfgang
Published: July 2012

Crystalline bacterial cell surface proteins (S‐layers) are introduced as immobilization matrices for binding biologically functional molecules in the development of amperometric biosensors. Due to the crystalline character of S‐layers, functional groups are located in well defined position and orientation on the protein meshwork and thus allow to bind molecules in densely packed monolayers. One of the most critical procedures in the development of amperometric biosensors is the deposition of an electrical contact onto the sensing layer. Conventional, sputtering techniques using platinum or gold, or, more recently, pulsed laser deposition of precious metals under inert gas conditions allow to establish electrically conductive contacts on S‐layer‐based enzyme electrodes.
The influence of amphiphiles with different chemical structure on the properties of fluid interfaces
Authors: Haage Klaus , Fiedler Harald , Esser Alfija
Published: July 2012

The influence of the hydrophilic/hydrophobic balance in several structures of amphiphiles on the surface activity was investigated. The aim was to compare model compounds combining different polar groups like ionic groups in acyl oligoglycinates or nonionic glycosides with glycyl spacer groups or with oxyethylene spacer groups. These functional groups are important in technically used surfactants and in native based amphiphiles like carbohydrates and proteins and derivatives, thus they are of interest from theoretical and practical reasons. The influence of the different groups is shown by the adsorption isotherms and the coalescence of oil droplets separated by thin aqueous surfactant films. The surface and interfacial tension of the homologous pure model compounds have been measured and fitted with the Frumkin equation. The influence of these small spacer groups can result in an increase of the hydrophilic strength of the surfactant as well as in an increase of the hydrophobic strength, depending on the total hydrophilic/hydrophobic balance in the amphiphile.
Continuous ultrafiltration of reverse micelles in the ternary system Igepal CA 520/cyclohexane/water
Authors: Schomäcker Reinhard , Orlich Bernhard , Braun Gerhard
Published: July 2012

The ultrafiltration is a separation technique at the nanometer scale and is applicable for the rejection of reverse micelles, spherical aggregates of surfactants, at membrane surfaces. We investigated the continuous ultrafiltration of reverse micelles in the non‐ionic ternary system Igepal CA 520/cyclohexane/water. The dependence of flux velocity and rejection on transmembrane pressure, droplet size, concentration of surfactant and temperature is described. With increasing pressure we also found micelles beside surfactant monomers in the permeate. This effect is observed more strongly when using non‐ionic surfactants than using ionic surfactants. It is discussed on the basis of the flexibility of the micelles. The results of the ultrafiltration process are compared with theoretical models, which are developed for the ultrafiltration of macromolecules from aqueous solutions: the gel layer models, which are developed for the ultrafiltration of macromolecules from aqueous solutions: the gel layer model, the model of osmotic pressure and the force balance model.
Synthesis of organic polymer gels in microemulsions and lyotropic mesophases
Authors: Hentze Hans‐Peter , Göltner Christine G. , Antonietti Markus
Published: July 2012

The synthesis of fine polymer latices and ordered polymer gels by polymerization in microemulsions and lyotropic mesophases is described. For this purpose, a new class of surfactants based on the coupling of cetyl trimethylammonium groups with organic counterions was developed. Interface activity, critical micelle concentration as well as lyotropic liquid crystalline phase behavior of these surfactants were investigated, and very high efficiency and high phase stability was found.

Systems optimized such do not only allow the synthesis of very small polymer latices (Rh≥7.5 nm) in reverse systems, but also the generation of gels with lamellar order. Due to the occurrence of phase transitions during polymerization, direct templating of the original lyotropic phase by the polymer gel is prevented, but the final polymer gels are highly ordered and reflect some of the characteristics of the surfactant template.
Study on the structure of reverse micelles of triton‐X‐100 at low water content
Authors: Kluge T. , Knoll H. , Helmstedt M.
Published: July 2012

UV/VIS absorption and emission of Ru(bpy)2+3, and time‐resolved luminescence quenching of Ru(bpy)2+3 by methylviologene were studied in reverse micelles (water‐in‐cyclohexane microemulsion) of triton‐X‐100 at low water content (hexanol‐1 as cosurfactant). From experimental results it is concluded that the probe molecules Ru(bpy)2+3 were solubilized in two different small aggregates at mole fractions of 1% water. Dynamic light scattering experiments however show large aggregates in these samples indicating a secondary structure. Increasing the water content, small aggregates with a radius of a few nm were detected by both light scattering and luminescence quenching, as expected.
Thermally stable CaO surfaces on highly dispersed MgO — New aspects for methane activation
Authors: Hofmann P. , Knözinger E. , Diwald O. , Mustafa A.
Published: July 2012

Chemical Vapour Deposition (CVD), applied to the production of mixed oxides of magnesium and calcium, provides nanostructured particles with outstanding surface properties which are dominated by low coordinated sites and CaO enrichment. The resulting basic material should, therefore, be particularly well suited for methane activation. In addition, it turned out to be extremely thermally stable.

In fact, FTIR spectroscopy clearly evidences efficient methane chemisorption on the new oxide material. EPR spectroscopy indicates the presence of new paramagnetic centres after the addition of methane. ‐ If the mixed oxide samples are exposed to UV irradiation (>320 nm) in the presence of a methane/oxygen mixture, IR bands appear which have to be attributed to larger homologous alkyl structures which are ‐ for different reasons ‐ not observed on the pure constituents (MgO, CaO). Thus relevant implications of the new oxide material are to be expected in the field of heterogeneous catalysis, in particular, of Oxidative Coupling of Methane (OCM).
Electrochemical investigation of the nanostructured composite (W, Ga)
Authors: Bolz H. , Schwitzgebel G.
Published: July 2012

Nanostructured composites (W,Ga)nc consist of tungsten crystallites 5‐10 nm thick and 10‐50 wt% gallium in the grain boundaries. Potentiometric measurements and cyclic voltammetry were performed in aqueous solution of Ga2(SO4)3. The electrode potential of the samples is 0.36 ± 0.03 V more positive than that of pure Ga. This value corresponds to the known binding energies of Ga layers on W single crystal surfaces (field ion microscopy). Therefore, there is strong evidence that the electrochemical behaviour is determined, in analogy to the under potential phenomena, by Ga monolayers in the surface regions of the grain boundaries.
The interaction of methyl chloride with a silicon(111) surface
Authors: Küster Regine , Christmann Klaus
Published: July 2012

In the technical Müller‐Rochow synthesis, dimethyl dichlorsilane (DMD) is fabricated from methyl chloride which interacts with a ‘contact mass’ consisting of elemental Si and Cu (Cu being a catalyst). In order to better understand some of the elementary steps of this reaction, we have followed the adsorption of methyl chloride on a (7×7) reconstructed Si(111) surface in the temperature range between 100 and 1000 K by means of LEED, Auger electron spectroscopy (AES), temperature‐programmed thermal desorption (TPD), vibrational loss spectroscopy (HREELS), and work function change (Δϕ) measurements. CH3C1 adsorbs effectively in a single weakly chemisorbed state. The adsorption energy is strongly coverage‐dependent and decreases from initially ˜ 40 kJ/mol to ˜ 30 kJ/mol near the monolayer. During adsorption, the work function of the Si(111) surface first increases sharply by 0.36 eV and saturates, after an intermediate maximum of ˜ 40 eV near the monolayer, at ˜ 0.61 eV. CH3C1‐derived vibrational losses appear at 88, 176, 340, and 370 meV and can be associated with known gas phase vibrations of CH3C1. An additional band at 260 meV is tentatively ascribed to the Si‐H stretching vibration, pointing to competing dissociation of adsorbed CH3C1 into hydrogen and methylene chloride CH2C1. Otherwise, CH3C1 does not react with Si(111) under our UHV conditions (CH3C1 partial pressures ≤10−5 mbar, 100 ≤T≤300 K), as the absence of any C1‐ and/or Si‐containing mass fragments in the TPD spectra proves. We deduce from our investigation that the combined chlorination and methylation of Si in the technical Müller‐Rochow process is dictated by processes which run only at much larger (atmospheric) pressures and/or elevated temperatures.
Molecular dynamics simulation of the proton transport in water
Authors: Schmidt Roger G. , Brickmann Jürgen
Published: July 2012

The proton transport in water is treated within a mixed molecular dynamic (MD) and Monte Carlo (MC) scheme. Therein the migration of a positive charge is treated as a two step process; (i) as a displacement of a hydronium ion and (ii) as a proton transfer between a hydronium ion and an adjacent water molecule. Both, the hydronium ion and the water molecules are treated as rigid molecules. It is found that the determining step for the proton transport rate is the dissociation rate of H5O2+complexes. In these complexes the O‐O distance is only 2.4–2.5 Å while the corresponding distance for two water molecules in solution is 2.83 Å. In the H5O2+complex the proton does no longer belong to a single water molecule, but is delocalized between the two oxygen atoms. This situation is modelled by an exchange of the water and the hydronium every time step with a probabilityp= 1/2.
Collisional deactivation of vibrationally highly excited benzyl radicals
Authors: Damm M. , Deckert F. , Hippler H.
Published: July 2012

The collisional deactivation of vibrationally highly excited benzyl radicals in the ground electronic state has been investigated. Vibrationally excited benzyl radicals have been generated using the fast dissociation of vibrationally excited ethylbenzene prepared from UV absorption followed by fast internal conversion. Subsequent to complete collisional deactivation the benzyl radicals have been reexcited by the absorption of a further UV‐photon also followed by fast internal conversion. Once again the collisional deactivation of the benzyl radicals has been monitored by time‐resolved UV absorption spectroscopy. Average energies transferred per collision have been determined by comparison of absorption‐time profiles with different initial vibrational energies. It was found that the rate of collisional deactivation of the open shell benzyl radical is almost identical to the rate of collisional deactivation of the closed shell hydrocarbons of similar size.
Engineering Strategies for Successful Development of Functional Polymers Using Oxidative Enzymes
Authors: Nyanhongo G. S. , Nugroho Prasetyo E. , Herrero Acero E. , Guebitz G. M.
Published: July 2012

Enzyme application in polymer engineering is rapidly increasing and is set to revolutionize many industries. Given the multidisciplinary nature of this field, it has become clear that successful development of functional polymers entails tapping into advances in bioengineering, molecular biology, genetic engineering, chemical engineering, biochemistry, material science, nanotechnology, etc. This review summarizes the different strategies and reaction conditions that can influence the synthesis or modification of polymers. It is hoped that this review will provide scientists from different backgrounds with information on the different reaction engineering strategies for the successful development of functional polymers using oxidative enzymes.
Solid‐State NMR Investigations of Supported Ionic Liquid Phase Water‐Gas Shift Catalysts: Ionic Liquid Film Distribution vs. Catalyst Performance
Authors: Haumann M. , Schönweiz A. , Breitzke H. , Buntkowsky G. , Werner S. , Szesni N.
Published: July 2012

The ionic liquid film distribution in supported ionic liquid phase (SILP) catalysts has been studied by solid‐state NMR. [EMIM][NTf2] was immobilized onto silica gel 100 support with loadings between 0 and 40 vol.‐%. The 1H NMR signals indicated an exchange process between the support's surface silanol groups and the protons of the ionic liquid. At ionic liquid loadings below 10 vol.‐%, islands of ionic liquids seemed to form, whereas at higher loadings complete coverage of the support was achieved. The NMR‐based film model was confirmed by gas phase water‐gas shift experiments using known SILP catalysts with different ionic liquid loadings. At high ionic liquid loading, the activity of the catalyst decreased due to pore blocking. The NMR technique provided easy and reliable data for film formation and distribution and allows for optimization of SILP catalysts in the future.
Screening of Colloids by Semicontinuous Centrifugation
Authors: Spelter L. E. , Meyer K. , Nirschl H.
Published: July 2012

This work contributes to the field of solid‐liquid separation in focusing on the screening of colloidal particles in a semicontinuous process. The aim of the study is to provide the basics for a continuous classification process in industry. After a short introduction to the field of particle screening, a review of the possibilities of classification in the gas or liquid phase is presented, including analytical methods, devices for the fractionation on the laboratory scale as well as apparatus for screening on the pilot and industrial scale. The results show the dispersion, stabilization and classification of fine kaolin and polystyrene particles. Kaolin was used to demonstrate the possibility of removing the fraction of fine particles, polystyrene particles were used to investigate the removal of the coarse fraction. The diameter of the particles used in this study ranges from 250 nm to 3 μm.
Intramolecular Gas‐Phase Reactions of Synthetic Nonheme Oxoiron(IV) Ions: Proximity and Spin‐State Reactivity Rules
Authors: Mas‐Ballesté Rubén , McDonald Aidan R. , Reed Dana , Usharani Dandamudi , Schyman Patric , Milko Petr , Shaik Sason , Que Lawrence
Published: July 2012

The intramolecular gas‐phase reactivity of four oxoiron(IV) complexes supported by tetradentate N4 ligands (L) has been studied by means of tandem mass spectrometry measurements in which the gas‐phase ions [FeIV(O)(L)(OTf)]+ (OTf=trifluoromethanesulfonate) and [FeIV(O)(L)]2+ were isolated and then allowed to fragment by collision‐induced decay (CID). CID fragmentation of cations derived from oxoiron(IV) complexes of 1,4,8,11‐tetramethyl‐1,4,8,11‐tetraazacyclotetradecane (tmc) and N,N′‐bis(2‐pyridylmethyl)‐1,5‐diazacyclooctane (L8Py2) afforded the same predominant products irrespective of whether they were hexacoordinate or pentacoordinate. These products resulted from the loss of water by dehydrogenation of ethylene or propylene linkers on the tetradentate ligand. In contrast, CID fragmentation of ions derived from oxoiron(IV) complexes of linear tetradentate ligands N,N′‐bis(2‐pyridylmethyl)‐1,2‐diaminoethane (bpmen) and N,N′‐bis(2‐pyridylmethyl)‐1,3‐diaminopropane (bpmpn) showed predominant oxidative N‐dealkylation for the hexacoordinate [FeIV(O)(L)(OTf)]+ cations and predominant dehydrogenation of the diaminoethane/propane backbone for the pentacoordinate [FeIV(O)(L)]2+ cations. DFT calculations on [FeIV(O)(bpmen)] ions showed that the experimentally observed preference for oxidative N‐dealkylation versus dehydrogenation of the diaminoethane linker for the hexa‐ and pentacoordinate ions, respectively, is dictated by the proximity of the target CH bond to the oxoiron(IV) moiety and the reactive spin state. Therefore, there must be a difference in ligand topology between the two ions. More importantly, despite the constraints on the geometries of the TS that prohibit the usual upright σ trajectory and prevent optimal σCH–σ* overlap, all the reactions still proceed preferentially on the quintet (S=2) state surface, which increases the number of exchange interactions in the d block of iron and leads thereby to exchange enhanced reactivity (EER). As such, EER is responsible for the dominance of the S=2 reactions for both hexa‐ and pentacoordinate complexes.
Application of a Structure/Oxidation‐State Correlation to Complexes of Bridging Azo Ligands
Authors: Das Amit , Scherer Thomas Michael , Mobin Shaikh M. , Kaim Wolfgang , Lahiri Goutam Kumar
Published: July 2012

Based on data from more than 40 crystal structures of metal complexes with azo‐based bridging ligands (2,2′‐azobispyridine, 2,2′‐azobis(5‐chloropyrimidine), azodicarbonyl derivatives), a correlation between the NN bond lengths (dNN) and the oxidation state of the ligand (neutral, neutral/back‐donating, radical‐anionic, dianionic) was derived. This correlation was applied to the analysis of four ruthenium compounds of 2,2′‐azobispyridine (abpy), that is, the new asymmetrical rac‐[(acac)2Ru1(μ‐abpy)Ru2(bpy)2](ClO4)2 ([1](ClO4)2), [Ru(acac)2(abpy)] (2), [Ru(bpy)2(abpy)](ClO4)2 ([3](ClO4)2), and meso‐[(bpy)2Ru(μ‐abpy)Ru(bpy)2](ClO4)3 ([4](ClO4)3; acac−=2,4‐pentanedionato, bpy=2,2′‐bipyridine). In agreement with DFT calculations, both mononuclear species 2 and 32+ can be described as ruthenium(II) complexes of unreduced abpy0, with 1.295(5)<dNN<1.320(3) Å, thereby exhibiting effects from π back‐donation. However, the abpy ligand in both the asymmetrical diamagnetic compound 12+ (dNN=1.374(6) Å) and the symmetrical compound 43+ (dNN=1.360(7), 1.368(8) Å) must be formulated as abpy.−. Remarkably, the addition of [RuII(bpy)2]2+ to mononuclear [RuII(acac)2(abpy0)] induces intracomplex electron‐transfer under participation of the noninnocent abpy bridge to yield rac‐[(acac)2Ru1III(μ‐abpy.−)Ru2II(bpy)2]2+ (12+) with strong antiferromagnetic coupling between abpy.− and RuIII (DFT (B3LYP/LANL2DZ/6‐31G*)‐calculated triplet–singlet energy separation ES=1−ES=0=11739 cm−1). Stepwise one‐electron transfer was studied for compound 1n, n=1−, 0, 1+, 2+, 3+, by UV/Vis/NIR spectroelectrochemistry, EPR spectroscopy, and by DFT calculations. Whereas the first oxidation of compound 12+ was found to mainly involve the central ligand to produce an (abpy0)‐bridged Class I mixed‐valent Ru1IIIRu2II species, the first reduction of compound 12+ affected both the bridge and Ru1 atom to form a radical complex (1+), with considerable metal participation in the spin‐distribution. Further reduction moves the spin towards the {Ru2(bpy)2} entity.
Re‐examining the Mechanisms of Competing Pericyclic Reactions of 1,3,7‐Octatriene
Authors: Gutierrez Osvaldo , Harrison Jason G. , Pemberton Ryan P. , Tantillo Dean J.
Published: July 2012

DFT (both B3LYP and M06‐2X), CASSCF, and CASPT2 calculations were used to investigate competing [3, 3] and [3, 5] sigmatropic shifts and intramolecular [4+2] cycloaddition of 1,3,7‐octatriene. In accord with previous results on 1,5‐hexadiene, CASSCF calculations found both stepwise and concerted pathways for the [3, 3] rearrangement. For the competing [3, 5] sigmatropic rearrangement, CASSCF and CASPT2 calculations revealed three stepwise pathways with similar barriers. UB3LYP and UM06‐2X calculations predicted a different potential energy landscape: no stepwise [3, 3] pathway, only two competing [3, 5] sigmatropic shifts, and an intramolecular Diels–Alder cycloaddition/homolytic ring‐opening pathway. Significant lowering of barriers for all rearrangements was predicted for some 1,3,7‐octatrienes with substituents at the 4‐ and 7‐positions.
ChemInform Abstract: The Polymorphism of CsThF5.
Authors: Underwood Christopher C. , Mann Matthew , McMillen Colin D. , Musgraves J. David , Kolis Joseph W.
Published: July 2012

Three new polymorphs of CsThF5 are hydrothermally synthesized from ThF4 and aqueous CsF solutions of varying concentrations in a silver ampule (autoclave, 575 °C, 2—12 d).
ChemInform Abstract: Fast, Solvent‐Free and Hydrogen‐Bonding‐Mediated Asymmetric Michael Addition in a Ball Mill.
Authors: Wang Yi‐Feng , Chen Ru‐Xiang , Wang Ke , Zhang Bin‐Bin , Li Zhao‐Bo , Xu Dan‐Qian
Published: July 2012

Cinchona‐derived squaramide is an efficient catalyst for the asymmetric Michael addition of 1,3‐dicarbonyl compounds to nitroolefins under solvent‐free conditions.
ChemInform Abstract: Highly Chemoselective Calcium‐Catalyzed Propargylic Deoxygenation.
Authors: Meyer Vera J. , Niggemann Meike
Published: July 2012

A highly chemoselective, Lewis acid‐catalyzed direct deoxygenation of both secondary and tertiary propargylic alcohols and ethers is developed.
ChemInform Abstract: Palladium‐Catalyzed Deamidative Arylation of Azoles with Arylamides Through a Tandem Decarbonylation—C—H Functionalization.
Authors: Li Chengliang , Li Pinhua , Yang Jin , Wang Lei
Published: July 2012

The highly chemo‐ and regioselective deamidative cross‐coupling of arylamides (II), as an aryl metal equivalent, with azoles (I), (IV), (VI) and (VIII) is described.
ChemInform Abstract: Magnetic Nanoparticles Catalyzed N‐tert‐Butoxycarbonylation of Amines and Amine Derivatives.
Authors: Akbari Jafar , Sajirani Soghra B. , Nezhad Jafar M. , Heydari Akbar
Published: July 2012

Mono N‐Boc protection of various amines succeeds chemoselectively in the presence of magnetically recoverable ferric oxide on silica nanoparticles.
ChemInform Abstract: A Copper‐Catalyzed Petasis Reaction for the Synthesis of Tertiary Amines and Amino Esters.
Authors: Frauenlob Robin , Garcia Carlos , Bradshaw Gary A. , Burke Helen M. , Bergin Enda
Published: July 2012

In the presence of CuBr/bipy, aldehydes bearing a coordinating group react smoothly with sterically unhindered amines and boronic acids.
ChemInform Abstract: Synthesis of Alcohols from m‐Fluorophenylsulfones and Dialkylboranes: Application to the C14—C35 Building Block of E7389.
Authors: Liu Lei , Henderson James A. , Yamamoto Akihiko , Bremond Paul , Kishi Yoshito
Published: July 2012

The method is applied to a broad spectrum of products including subunit (VIII).
ChemInform Abstract: Palladium‐Catalyzed C—N Cross‐Coupling of Sulfinamides and Aryl Halides.
Authors: Sun Xiaofei , Tu Xingzhao , Dai Chuan , Zhang Xiaoping , Zhang Binbin , Zeng Qingle
Published: July 2012

Optimized conditions A) render possible the title reaction with aryl chlorides and bromides.
ChemInform Abstract: Consecutive Michael—Claisen Process for Cyclohexane‐1,3‐dione Derivative (CDD) Synthesis from Unsubstituted and Substituted Acetone.
Authors: Sharma Dharminder , Bandna Bandna , Shil Arun K. , Singh Bikram , Das Pralay
Published: July 2012

Regioselective Michael reaction of ketones with alkyl acrylate derivatives is followed by Claisen cyclization to produce substituted cyclohexane‐1,3‐diones.
ChemInform Abstract: Microwave‐Assisted Copper‐Catalyzed Cross‐Coupling Reaction of Alkynes with Aryl Iodides and Vinyl Halides.
Authors: Tsai Wen‐Ting , Lin Yun‐Yung , Wang Yu‐Jen , Lee Chin‐Fa
Published: July 2012

In the presence of 2‐5 mol% CuI(Xantphos), the process is highly efficient for a broad spectrum of substrates bearing various functionalities.
ChemInform Abstract: Direct, Enantioselective Iridium‐Catalyzed Allylic Amination of Racemic Allylic Alcohols.
Authors: Lafrance Marc , Roggen Markus , Carreira Erick M.
Published: July 2012

For the first time the enantioselective displacement of secondary alcohols to give directly primary amines is presented.
ChemInform Abstract: Ligand‐Free Copper‐Catalyzed Coupling of Nitroarenes with Arylboronic Acids.
Authors: Zhang Jilei , Chen Jiuxi , Liu Miaochang , Zheng Xingwang , Ding Jinchang , Wu Huayue
Published: July 2012

A new protocol for the synthesis of diaryl ethers via an unprecedented Cu‐catalyzed coupling of nitroarenes with arylboronic acids is developed.
ChemInform Abstract: Asymmetric Catalytic Mannich‐Type Reaction of Hydrazones with Difluoroenoxysilanes Using Imidzaoline‐Anchored Phosphine Ligand—Zinc(II) Complexes.
Authors: Yuan Zhiliang , Mei Liangyong , Wei Yin , Shi Min , Kattamuri Padmanabha V. , McDowell Patrick , Li Guigen
Published: July 2012

A novel catalytic system is successfully applied to the mild title reaction.
ChemInform Abstract: Stereoselective Synthesis of Hydroxy Stilbenoids and Styrenes by Atom‐Efficient Olefination with Thiophthalides.
Authors: Mitra Prithiba , Shome Brateen , De Saroj Ranjan , Sarkar Anindya , Mal Dipakranjan
Published: July 2012

The preparation of the title compounds is accomplished with high (E)‐stereoselectivity where only elemental sulfur is lost.
ChemInform Abstract: Concise Synthesis of Chiral 2(5H)‐Furanone Derivatives Possessing 1,2,3‐Triazole Moiety via One‐Pot Approach.
Authors: Tan Yue‐He , Li Jian‐Xiao , Xue Fu‐Ling , Qi Ji , Wang Zhao‐Yang
Published: July 2012

The target compounds can be synthesized via a four‐component one‐pot method, a three‐component one‐pot method or a sequential method.
ChemInform Abstract: Copper(I)‐Mediated Cascade Reactions: An Efficient Approach to the Synthesis of Functionalized Benzofuro[3,2‐d]pyrimidines.
Authors: Chao Bo , Lin Shijun , Ma Qingdong , Lu Dong , Hu Youhong
Published: July 2012

The process renders possible the access to various medicinally important heterocyclic scaffolds.
ChemInform Abstract: Copper‐Catalyzed C—H Oxidation/Cross‐Coupling of α‐Amino Carbonyl Compounds.
Authors: Wu Ji‐Cheng , Song Ren‐Jie , Wang Zhi‐Qiang , Huang Xiao‐Cheng , Xie Ye‐Xiang , Li Jin‐Heng
Published: July 2012

A novel, mild, and selective method for the synthesis of the compounds (III), (V), (VI), (VIII), and (IX) is reported.
ChemInform Abstract: Highly Efficient Oxidation of 2‐Imidazoline‐5‐carboxylic Derivatives to Imidazole‐5‐carboxylic Derivatives by Dioxygen.
Authors: Huang Yue , Zu Xiaodong , Wu Fan , Xu Jinyi , Wu Xiaoming , Yao Hequan
Published: July 2012

A clean, mild and environmental‐benign method for the oxidation of imidazolines by dioxygen (or air) as the sole oxidant is developed.
ChemInform Abstract: Palladium‐Catalyzed Cyclization Reactions of 2,3‐Allenyl Amines with Propargylic Carbonates.
Authors: Ye Juntao , Li Suhua , Ma Shengming
Published: July 2012

The method allows the preparation of various highly functionalized oxazole structures, which are of importance in synthetic and medicinal chemistry.
ChemInform Abstract: Design and Application of New Imidazolylsulfonate‐Based Benzyne Precursor: An Efficient Triflate Alternative.
Authors: Kovacs Szabolcs , Csincsi Adam I. , Nagy Tibor Zs. , Boros Sandor , Timari Geza , Novak Zoltan
Published: July 2012

Sulfonylimidazole‐based benzyne precursors are utilized in the reactions with azides to form benzotriazoles, with tosyl hydrazone to form indazoles, with β‐ketoesters to form acyl alkylation products or with furans or pyrroles to form bridged compounds.
ChemInform Abstract: DBU‐Catalyzed Expeditious and Facile Multicomponent Synthesis of N‐Arylquinolines under Microwave Irradiation.
Authors: Singh Satish Kumar , Singh Krishna Nand
Published: July 2012

An efficient one‐pot three‐component microwave‐assisted reaction of aromatic aldehydes, 3‐arylamino‐5,5‐dimethylcyclohex‐2‐enone, and active methylene compounds catalyzed by DBU leads to various N‐arylquinoline derivatives (IV) (23 examples).
ChemInform Abstract: Nucleophilic Addition to 2,3‐Pyridyne and Synthesis of Benzonaphthyridinones.
Authors: Fang Yuesi , Larock Richard C.
Published: July 2012

The reaction of primary amine analogues of compounds (IX) leads to a complex mixture.
ChemInform Abstract: Intramolecular Sila‐Matteson Rearrangement: A General Access to Silylated Heterocycles.
Authors: Francois Cyril , Boddaert Thomas , Durandetti Muriel , Querolle Olivier , Van Hijfte Luc , Meerpoel Lieven , Angibaud Patrick , Maddaluno Jacques
Published: July 2012

Higher yields and chemoselectivities are observed when tBuLi is used as a lithiating agent.
ChemInform Abstract: Highly Efficient Synthesis of a Class of Novel Chiral‐Bridged Atropisomeric Monophosphine Ligands via Simple Desymmetrization and Their Applications in Asymmetric Suzuki—Miyaura Coupling Reaction.
Authors: Wang Shouliang , Li Jinjin , Miao Tingting , Wu Wenhao , Li Qing , Zhuang Yue , Zhou Zhongyuan , Qiu Liqin
Published: July 2012

Among various derivatives, ligand (I) is found to be the most efficient one to produce axially chiral organophosphorus compounds.
ChemInform Abstract: Synthesis of Water‐Soluble Phosphine Oxides by Pd/C‐Catalyzed P—C Coupling in Water.
Authors: Rummelt Stephan M. , Ranocchiari Marco , van Bokhoven Jeroen A.
Published: July 2012

The reaction proceeds without any ligands or additives in water and is environmentally friendly.
ChemInform Abstract: A Selective Intramolecular Transacylation of Taxoids Accompanying with the Oxetane Ring Opening.
Authors: Gao Feng , Yu Min , Chen Qiao‐Hong , Wang Feng‐Peng
Published: July 2012

Intramolecular transacylation from C‐4 to C‐5 of taxoids in the presence of TiCl4 proceeds with concomitant oxetane D‐ring opening to give novel taxoid derivatives, as demonstrated for paclitaxel (I).
ChemInform Abstract: Aza‐Claisen Rearrangement of 2‐C‐Hydroxymethyl Glycals as a Versatile Strategy Towards Synthesis of Isofagomine and Related Biologically Important Azasugars.
Authors: Reddy Y. Suman , Kancharla Pavan K. , Roy Rashmi , Vankar Yashwant D.
Published: July 2012

Rearrangement of hydroxymethyl glycals (I) leads to glycosyl trichloroacetamidates (III) as a mixture of α‐ and β‐anomers which are versatile precursors for the synthesis of several biologically active azasugars such as isofagomine (IV).
ChemInform Abstract: Racemic and Diastereoselective Construction of Indole Alkaloids under Solvent‐ and Catalyst‐Free Microwave‐Assisted Pictet—Spengler Condensation
Authors: Jida Mouhamad , Soueidan Olivier‐Mohamad , Deprez Benoit , Laconde Guillaume , Deprez‐Poulain Rebecca
Published: July 2012

18 examples
ChemInform Abstract: Recent Advances in Large‐Scale Assembly of Semiconducting Inorganic Nanowires and Nanofibers for Electronics, Sensors and Photovoltaics
Authors: Long Yun‐Ze , Yu Miao , Sun Bin , Gu Chang‐Zhi , Fan Zhiyong
Published: July 2012

Review: 200 refs.
ChemInform Abstract: Oxide Semiconductor Thin‐Film Transistors: A Review of Recent Advances
Authors: Fortunato E. , Barquinha P. , Martins R.
Published: July 2012

Review: 500 refs.
ChemInform Abstract: Cobalt(II)/Manganese(II)‐Based Molecular Metamagnets
Authors: Zhou YanLing , Hu YueQiao , Zeng MingHua
Published: July 2012

Review: 44 refs.
ChemInform Abstract: Tridentate Ligands and Beyond in Group IV Metal α‐Olefin Homo‐/Co‐Polymerization Catalysis
Authors: Redshaw Carl , Tang Yong
Published: July 2012

Review: 98 refs.
ChemInform Abstract: Synthesis of Polyfluoroalkyl Containing Thiopyran Derivatives and Their Applications in Fluoroorganic Chemistry.
Authors: Siry Sergiy A. , Timoshenko Vadim M. , Bouillon Jean‐Philippe
Published: July 2012

Review: 55 refs.
ChemInform Abstract: Conversion of Lignocellulose into Renewable Chemicals by Heterogeneous Catalysis.
Authors: Kobayashi Hirokazu , Ohta Hidetoshi , Fukuoka Atsushi
Published: July 2012

Review: 108 refs.
ChemInform Abstract: Role of Mixed Metal Oxides in Catalysis Science — Versatile Applications in Organic Synthesis
Authors: Gawande Manoj B. , Pandey Rajesh K. , Jayaram Radha V.
Published: July 2012

Review: ca. 100 refs.
ChemInform Abstract: Indoles in Multicomponent Processes (MCPs)
Authors: Shiri Morteza
Published: July 2012

Review: 361 refs.
ChemInform Abstract: Benzylic Amide Rotaxanes: A Versatile Architecture
Authors: Fioravanti Giulia
Published: July 2012

Review: 116 refs.
ChemInform Abstract: Imaging Nanoscale Magnetism and Its Fast Dynamics with Soft X‐Ray Microscopy
Authors: Fischer Peter
Published: July 2012

Review: 31 refs.
ChemInform Abstract: Chemical Constituents of Plants from the Genus Euonymus
Authors: Zhu Jia‐Xian , Qin Jiang‐Jiang , Chang Rui‐Jie , Zeng Qi , Cheng Xiang‐Rong , Zhang Fei , Jin Hui‐Zi , Zhang Wei‐Dong
Published: July 2012

Review: 106 refs.
ChemInform Abstract: Biological Stimuli and Biomolecules in the Assembly and Manipulation of Nanoscale Polymeric Particles
Authors: Randolph Lyndsay M. , Chien Miao‐Ping , Gianneschi Nathan C.
Published: July 2012

Review: 239 refs.
ChemInform Abstract: Extending the Aminocatalytic HOMO‐Raising Activation Strategy: Where Is the Limit?
Authors: Arceo Elena , Melchiorre Paolo
Published: July 2012

Review: 14 refs.
ChemInform Abstract: Advances in Fingerprint Analysis
Authors: Hazarika Pompi , Russell David A.
Published: July 2012

Review: by using mass spectrometric methods; 79 refs.
Computed diffusion contribution in the complex blood oxygenation‐level dependent fMRI signal
Authors: Chen Zikuan , Calhoun Vince D.
Published: July 2012

Diffusion is a ubiquitous phenomenon in blood oxygenation‐level dependent (BOLD) functional magnetic resonance imaging (fMRI), but it cannot be completely separated out from BOLD signals experimentally or theoretically. Nevertheless, it is possible to numerically characterize the diffusion‐only contribution by Monte Carlo simulation and signal analysis. The simulation was carried out for a variety of parameter settings of cortical vasculature (vessel radii = [2, 16] micron) and field strength (B0 = [0.18, 12.9] T). A cortical voxel was simulated in a cube of size 320 × 320 × 320 micron3 filled with a random vascular network. Diffusion‐present and diffusion‐absent signals were calculated by intravoxel dephasing (via switching on and off the diffusion coefficients) for a range of echo times TE = [0, 60] ms. Given a pair of diffusion‐present and diffusion‐absent complex signals, the diffusion‐only contribution was calculated by two signal analysis models: multiplication and addition. Statistics were rendered through multiple random realizations for each vasculature setting. Simulations suggest that diffusion contributes to BOLD signal (for setting of vessel radius = 3 micron, B0 = 3 T, TE = 30 ms) by a signal amplitude decay rate change of 0.8 Hz (multiplication model) or by a signal amplitude change percentage of 5% (addition model). Overall, this contribution is maximal amid a large range of field strengths, diminishing toward low and high fields. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part A 40A: 128–145, 2012.
Topological comparison‐based wormhole detection for MANET
Authors: Chan King Sun , Alam Mohammad Rafiqul
Published: July 2012

Wormhole attack is considered one of the most threatening security attacks for mobile ad hoc networks. In a wormhole attack, a tunnel is setup in advance between two colluders. The colluders record packets at one location and forward them through the tunnel to another location in the network. Depending on whether or not the colluders are participating in the network functions, the wormhole attack can be further divided into two categories: traditional wormhole attack and Byzantine wormhole attack. Existing researches focusing on detecting traditional wormhole attacks can be classified into three categories: one‐hop delay‐based approach, topological analysis‐based or special hardware/middleware‐based approaches. Unfortunately, they all have their own limitations. Most of the researches detecting Byzantine wormhole attack are not addressing the Byzantine wormhole attack directly. Instead, they focus on observing the consequence after a Byzantine wormhole attack, like packet dropping or modification. In this paper, we propose to detect both traditional and Byzantine wormhole attacks by detecting some topological anomalies introduced by wormhole tunnels. Simulation results show that our scheme can achieve both high wormhole attack detection rate and accuracy. Our scheme is also simple to implement. Copyright © 2012 John Wiley & Sons, Ltd.
Seamless management of paper and electronic documents for task knowledge sharing
Authors: Kojima Hiroyuki , Iwata Ken
Published: July 2012

Due to the progress of Internet technology and the increase of distributed information on networks, the present approach to knowledge management has been based more and more on the performance of various experienced users. In addition to the increase in electronic documents, the use of paper documents has not been reduced due to their convenience. This paper describes a method of tracking paper document locations and contents using radio frequency identification (RFID) technology. This research also focuses on the expression of a task process and the seamless structuring of related electronic and paper documents as a result of task knowledge formalization using information organizing. A system is proposed here that implements information organization for both Web documents and paper documents using the task model description and RFID technology. Examples of a prototype system are also presented. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(8): 52–63, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10370
A micro ultrasonic scalpel with modified stepped horn
Authors: Kurosawa Minoru , Umehara Yuji
Published: July 2012

A transducer for a micro ultrasonic scalpel has been fabricated. The micro ultrasonic scalpel can be used with an endoscope for a nonabdominal operation or microsurgery, for example, through a microscope. The ultrasonic transducer is 9.8 mm long and 2.7 mm wide and has a stepped horn to amplify the vibration velocity; the tip of the horn is 0.6 mm wide. The scalpel operated at the resonance frequency in the longitudinal mode at 278 kHz. The piezoelectric material was lead zirconate titanate (PZT), which was deposited using the hydrothermal method. The vibration velocity at the tip of the horn in the longitudinal direction was 4.0 m/s, with a 40 Vp‐p driving voltage in both of the side electrodes. To demonstrate the beneficial effect of the scalpel, a cutting test in which the transducer was stuck into pork fat was carried out. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(8): 44–51, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10414
Deformation of varifocal mirror with narrow frame by SOI wafer residual stress
Authors: Sasaki Takashi , Hane Kazuhiro
Published: July 2012

Silicon‐on‐insulator (SOI) wafers are used for many micro‐electro‐mechanical systems (MEMS). The influences of residual stress of SOI wafer on the fabricated structures are important especially for micro‐mirror because the optical performances are often affected by them. In this study, we propose an analytical calculation for the deformation of mirror and frame of a varifocal mirror. The deformations of the fabricated structures were measured using a white light interferometer. The frame was tilted at 2.8 mrad which was explained by the calculated value of 3.9 mrad. The mirror was deflected by 100 nm with the top‐flat shape, which also agreed well with the proposed analysis. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(8): 26‐33, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11381
Study of plant bioelectric potential response due to photosynthesis reaction
Authors: Ando Ki , Hasegawa Yuki , Yaji Tamaki , Uchida Hidekazu
Published: July 2012

Bioelectric potential is generated by ions in a plant cell; the potential changes with physiological activities of the plant. Therefore, measurement of the potential is a promising method for evaluation of plant activities. In this study, we investigated the mechanism of potential response generation due to photosynthetic reactions of plants. For this purpose, we measured the bioelectric potential with air replaced by N2 gas in order to suppress the carbon‐fixation reaction. The potential response was found to be different from the ambient gas, and we determined that several behaviors of the potential response were strongly related to the activities of the photochemical reaction and carbon‐fixation reaction. We next measured the potential when the illuminating conditions were changed to accelerate or decelerate photosynthesis. The shape of the potential response was found to be related to the increase or decrease of photosynthetic rate and can provide support for effective cultivation. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(8): 10–16, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11393
CHBr3/TiCl4/Mg as an Unusual Nucleophilic CBr2 Carbenoid: Effective and Chemoselective Dibromomethylenation of Aldehydes and Ketones
Authors: Bhorge Yeshwant Ramchandra , Chang Cheng‐Ta , Chang Su‐Haur , Yan Tu‐Hsin
Published: July 2012

We report that instead of using CBr4, CHBr3 can serve as a highly nucleophilic dibromomethylene carbenoid in chemoselective carbonyl dibromomethylenation. Successful application of the dibromomethylenation to various carbonyl compounds such as enolizable and sterically hindered ketones by using the CHBr3/Mg/TiCl4 system highlights the weakly basic nature, extraordinary reactivity, and synthetic versatility of the approach.
Synthesis of Coenzyme Q10
Authors: Oh Eun‐Taek , Jin Kim Hee , Taek Oh Jung , Su Liang , Yun Inkyun , Nam Kyunggu , Min Jae‐Hong , Woo Kim Joon , Koo Sangho
Published: July 2012

A practical synthesis of coenzyme Q10 has been developed. The route features an improved Friedel–Crafts allylation of tetramethoxytoluene with a para‐chlorobenzenesulfonyl‐substituted C5 allylic chloride at 40 °C. Replacement of the methyl ether protecting groups of the para‐hydroquinone by methoxymethyl groups at Q1 stage proceeded efficiently, and allowed the facile final oxidation to coenzyme Q10 to occur under mild acidic conditions. The overall yield of coenzyme Q10 from commercially available tetramethoxytoluene reached 53 % in this improved procedure.
Resveratrol‐Related Dehydrodimers: Laccase‐Mediated Biomimetic Synthesis and Antiproliferative Activity
Authors: Bhusainahalli Vedamurthy M. , Spatafora Carmela , Chalal Malik , Vervandier‐Fasseur Dominique , Meunier Philippe , Latruffe Norbert , Tringali Corrado
Published: July 2012

Seven resveratrol‐related monomeric stilbenoids were submitted to biomimetic oxidative coupling in the presence of laccase from Trametes versicolor (TvL), and gave racemic dihydrobenzofuran dehydrodimers (±)‐15 to (±)‐21. These products, after spectral characterization, were submitted to an antiproliferative activity bioassay against SW480 human colon cancer cells. Five racemates were found to be active, and were resolved by chiral HPLC. The pure enantiomers were subjected to circular dichroism measurements to establish their absolute configurations at C‐7 and C‐8. These enantiomerically pure compounds were submitted to the antiproliferative activity assay towards SW480 cells, and were all shown to be active with IC50 values in the approximate range 20–90 μM. In some cases, a significant difference between the activity of the 7R,8R and 7S,8S enantiomers was observed, but a defined configuration of the stereogenic centers does not appear to be a structural requirement for the activity. The comparison between the most active compounds and the inactive ones strongly suggests that the presence of a methoxy group in the position ortho to the C‐4 hydroxy group is highly detrimental to the activity.
Synthesis of Substituted Benzyl Homo‐C‐Ribonucleosides and ‐Nucleotides as Carba Analogues of Phosphoribosylanthranilate
Authors: Kubelka Tomáš , Slavětínská Lenka , Hocek Michal
Published: July 2012

New 2‐substituted benzyl C‐ribonucleosides and ‐nucleotides were designed as carba analogues of phosphoribosylanthranilate, a key intermediate in tryptophan biosynthesis. The synthesis was based on the preparation of TBS‐protected 2‐bromobenzyl C‐ribonucleoside 4a by addition of (2‐bromobenzyl)magnesium bromide to ribonolactone followed by reduction and subsequent functional group transformations. Pd‐catalyzed hydrogenation, cross‐couplings, amination or hydroxylation, as well as lithiation followed by reaction with CO2 and amidations, gave a large series of 2‐alkyl‐, 2‐(het)aryl, 2‐amino, 2‐hydroxy, 2‐carboxy and 2‐carbamoyl derivatives that were deprotected to afford free homo‐C‐ribonucleosides. Some of the title nucleosides were converted to 5′‐O‐phosphates.
Distribution and sources of polybrominated diphenyl ethers in the Southern California Bight
Authors: Dodder Nathan G. , Maruya Keith A. , Lauenstein Gunnar G. , Ramirez Juan , Ritter Kerry J. , Schiff Kenneth C.
Published: July 2012

Polybrominated diphenyl ethers (PBDEs) were measured in surface sediments from 121 locations within the Southern California Bight. Site selection was based on a probabilistic approach to determine the spatial extent and magnitude of PBDE concentrations with known confidence intervals. Coastal embayments (including estuaries, marinas, ports, and bays) and the continental shelf out to the lower slope were sampled. Thirteen PBDEs were detected at 92 of the sites, with a geometric mean and maximum of 4.7 and 560 ng/g dry weight (sum of 13 congeners), respectively. The PBDE concentrations were higher in coastal embayments than in offshore locations. Embayments had an area-weighted geometric mean total PBDE concentration of 12 (95% confidence interval, 8.0–17) ng/g dry weight and a total PBDE mass of 110 (77–160) kg. The offshore stratum, which is 99% of the total area, had an area-weighted geometric mean total PBDE concentration of 2.0 (1.6–2.5) ng/g dry weight and a total PBDE mass of 860 (700–1,100) kg. The five highest PBDE concentrations were associated with the mouths of urban rivers, indicating that urban runoff is likely a major input of PBDEs to these coastal marine waters. The outfalls of wastewater treatment plants were not observed to be major sources. Environ. Toxicol. Chem. 2012; 31: 2239–2245. © 2012 SETAC