bluuebunny/crossref_metadata_2025 huggingface dataset:
“NiSn” — A nanostructured compound
Authors: Schwitzgebel G. , Mildenberger R.
Published: July 2012

The recent finding that “NiSn” is composed of Ni3Sn2 with additions of Ni3Sn4 and a Sn(II) compound, SnO or Sn(OH)2, permits to develop a refined model of its structure and stability. The mean grain diameter was determined by STM (15 nm) with a rather small variance. Electrode potentials could be measured in a fused salt mixture of SnCl2 and KC1 between 240 and 300°C. Their evolution with time was consistently interpreted by assuming a solid state separation of Ni3Sn4 from the Ni‐deficient metastable phase Ni3‐δSn2. This model is in good agreement with earlier results of excess enthalpies and XRD changes measured during the recrystallization process.
NMR investigations of nanostructured ceramics
Authors: Edgar M. , Schubert M. , Limbach H. H. , Göltner C. G.
Published: July 2012

Nanostructured mesoporous silicates displaying hexagonally arranged channels, templated using a liquid crystal mesophase, were investigated using H‐2 and N‐15 NMR spectroscopy. It is shown that N‐15 MAS NMR spectroscopy allows to estimate the surface acidity of mesoporous materials by measuring the N‐H bond length via the N‐15 chemical shift. Further, H‐2 and N‐15 NMR spectroscopy identify significant differences between the structure of the surface area of HI, silica and MCM‐41. Static N‐15 NMR spectroscopy was used to differentiate between pyridine located in channels perpendicular to the magnetic field from, for example, pyridine located in channels orientated parallel to the field. This observation offers the possibility of separating the NMR signals and thus pursuiting the goal of “liquid phase single crystal NMR spectroscopy”.
Density functional study of model species for nucleic acids and lipids
Authors: Hill Jörg‐Rüdiger , Liang Congxin
Published: July 2012

Density functional calculations for dimethylphosphate, methylpropylphosphate, 1‐methylphosphoryl‐2‐acetoxy‐propane, and methylphosphorylcholine which can serve as model species for nucleic acids and lipids were carried out. The VWN, BPW91, BLYP, and ACM functionals have been used and the results are compared with results obtained within the Hartree‐Fock and MP2 approximations and, where available, with observed data. Conformational energies are generally in good agreement with MP2 results for the BPW91, BLYP, and ACM functionals if no intramolecular hydrogen bonds are present. The performance of the VWN functional is not satisfying. Geometries can be predicted with all tested functionals reasonably well and are closer to observed values than Hartree‐Fock results.
The thermally induced phase transition in 2,3,7,8‐tetramethoxythianthrene
Authors: Sanchis M. J. , Marthe S. , Calleja R. Díaz , Martínez E. Sánchez , Epple M. , Klar G.
Published: July 2012

2,3,7,8‐Tetramethoxythianthrene is known to crystallize in orthorhombic and monoclinic polymorphs, depending on the solvent used for crystallization. Upon heating the orthorhombic form to ca. 150°C, an enantiotropic (reversible) phase transition into the monoclinic phase occurs. This phase transition has been characterized by different techniques: differential scanning calorimetry (DSC), temperature‐resolved X‐ray powder diffractometry (TXRD), and thermally stimulated depolarization current measurements (TSDC). A mechanism for this solid‐state transition is proposed based on single‐crystal X‐ray structures.
A laser flash photolysis study of the decay of Cl‐Atoms and Cl2− radical anions in aqueous solution at 298 K
Authors: Jacobi H.‐W. , Herrmann H. , Zellner R.
Published: July 2012

The rate coefficient for the reaction of Cl atoms with (1) H2O and of Cl2− radical anions with (2) H2O and (3) OH− have been determined using laser photolysis for the generation of Cl/Cl2− and long path laser absorption for the time resolved detection of Cl2−. The following results were obtained: k1 = (2.3 + 0.6)· 105 s−1, k2 < 610s−1 and k3 = (4.0 + 0.6)· 106M−1s−1. It is concluded that the lifetime of Cl/Cl2− in aqueous solution strongly depends on the Cl− content and on pH.
Dielectric relaxation of aqueous solutions of ribonuclease A in the absence and presence of urea
Authors: Abou‐Aiad T. , Becker U. , Biedenkap R. , Brengelmann R. , Elsebrock R. , Hinz H.‐J. , Stockhausen M.
Published: July 2012

The dielectric spectra of aqueous solutions of ribonuclease A (RNase) have been measured in the frequency domain over the whole absorption region between 2 MHz and 72 GHz at 20°C in two solvents, pure water and 8 mol/1 urea solution. These environmental conditions promote the native and unfolded state of the protein, respectively. The results are discussed with regard to (i) the low and (ii) the high frequency part of the spectra. The contribution to (i) which is attributable to the tumbling motion of RNase is changed by the presence of urea, indicating that the RNase moieties are increased in polarity, but only insignificantly in size. From (ii) it is concluded that addition of urea leads to a change in the overall water structure and dynamics which is accompanied by an increased fraction of non‐associated solvent molecules. These are likely to be instrumental in the denaturation process.
A novel catanionic surfactant: Hexadecyltrimethylammonium dodecyl sulfate
Authors: Tomašić V. , Popović S. , Tušek‐Božić Lj. , Pucić I. , Filipović‐Vinceković N.
Published: July 2012

The novel catanionic surfactant, hexadecyltrimethylammonium dodecyl sulfate, was prepared from the equimolar aqueous solutions of cationic, hexadecyltrimethylammonium bromide, and anionic, sodium dodecyl sulfate, surfactants. The composition, structure, morphology and thermal behavior of new compound were determined by chemical, X‐ray diffraction, IR and 1H NMR spectra analyses, differential scanning calorimetry, thermogravimetry and polarizing microscopy.

The thermal behavior of solid crystalline CTADS is rather complex because of its polymorphism, thermotropic mesomorphism and coexistence of ordered and disordered phases below the melting temperature. There are two parallel mechanisms during heating: structural transition of the system and transition from solid crystalline to liquid crystalline phase.

Several polymorphic phases, all of the bilayered structure, were observed exhibiting a change of the basic lamellar thickness with temperature. Polarizing microscopy revealed a characteristic texture of the smectic phase.
Dynamic and thermodynamic aspects of polymer‐surfactant interactions: The SDS‐PVP‐water system
Authors: Persi Livio , la Mesa Camillo , D'Aprano Alessandro
Published: July 2012

The water‐PVP (polyvinylpyrrolidone)‐SDS (sodium dodecylsulfate) system has been investigated by ultrasonic relaxation measurements. In water‐PVP mixtures the relaxation time is independent on the polymer content, whereas in water‐SDS solutions it decreases on increasing the amount of surfactant in micellar form. In the ternary water‐PVP‐SDS systems, at fixed PVP content, three different regions have been observed on increasing the amount of SDS: namely, at very low surfactant content the relaxation time, τ, increases then remains nearly constant and finally decreases. The above behaviour has been ascribed to surfactant binding onto the polymer and to micelle formation, respectively. By analysing the dependence of relaxation time(s) on composition, it was possible to divide the investigated region in three domains (i.e. non interaction region, polymer‐surfactant interaction region and micellar region). A phase diagram for the above system was drawn according to the experimental kinetic results. From the data obtained by ultrasonic relaxation experiments the number of SDS molecules bound to PVP, (m), was evaluated and the Gibbs energy of binding, [ΔGbind/], calculated.
Hollow fiber‐based liquid membrane microextraction combined with high‐performance liquid chromatography for extraction and determination of trimetazidine in human plasma
Authors: Lv Jiang , Zhao Xu , Ye Jing , Liu Dan , Chen Xiaohui , Bi Kaishun
Published: July 2012

A hollow fiber‐based liquid phase microextraction strategy combined with high‐performance liquid chromatography was evaluated for the quantitative determination of trimetazidine in human plasma. Trimetazidine was extracted from a 2.1 mL basified plasma sample (donor phase) into the organic solvent (n‐octanol) impregnated in the pores of a hollow fiber and then extracted into an acidic solution (acceptor phase) inside the lumen of the hollow fiber. The result showed that transport of drugs from alkaline sample solution into 0.5 m HCl occurred efficiently when 25 μL of 250 mm sodium 1‐octanesulfonate was added into the donor phase. Several parameters influencing the efficiency of the method, such as the nature of organic solvent used to impregnate the membrane, compositions of donor phase and acceptor phase, type and concentration of carrier, extraction time, stirring rate and salt concentration, were investigated and optimized. Under the optimal conditions, the calibration curves were obtained in the range of 5–200 ng/mL with reasonable linearity (r > 0.9980). The method was successfully applied to determine the concentration of trimetazidine in human plasma. Copyright © 2012 John Wiley & Sons, Ltd.
Stereochemistry of Molecular Figures‐of‐Eight
Authors: Boyle Megan M. , Gassensmith Jeremiah J. , Whalley Adam C. , Forgan Ross S. , Smaldone Ronald A. , Hartlieb Karel J. , Blackburn Anthea K. , Sauvage Jean‐Pierre , Stoddart J. Fraser
Published: July 2012

A trans isomer of a figure‐of‐eight (Fo8) compound was prepared from an electron‐withdrawing cyclobis(paraquat‐p‐phenylene) derivative carrying trans‐disposed azide functions between its two phenylene rings. Copper(I)‐catalyzed azide–alkyne cycloadditions with a bispropargyl derivative of a polyether chain, interrupted in its midriff by an electron‐donating 1,5‐dioxynaphthalene unit acting as the template to organize the reactants prior to the onset of two click reactions, afforded the Fo8 compound with Ci symmetry. Exactly the same chemistry is performed on the cis‐bisazide of the tetracationic cyclophane to give a Fo8 compound with C2 symmetry. Both of these Fo8 compounds exist as major and very minor conformational isomers in solution. The major conformation in the trans series, which has been characterized by X‐ray crystallography, adopts a geometry which maximizes its CH⋅⋅⋅O interactions, while maintaining its π⋅⋅⋅π stacking and CH⋅⋅⋅π interactions. Ab initio calculations at the M06L level support the conformational assignments to the major and minor isomers in the trans series. Dynamic 1H NMR spectroscopy, supported by 2D 1H NMR experiments, indicates that the major and minor isomers in both the cis and trans series equilibrate in solution on the 1H NMR timescale rapidly above and slowly below room temperature.
ChemInform Abstract: Fluoride‐Ion Acceptor Properties of WSF4: Synthesis, Characterization, and Computational Study of the WSF‐5 and W2S2F9‐ Anions and 19F NMR Spectroscopic Characterization of the W2OSF9‐ Anion.
Authors: Nieboer Jared , Haiges Ralf , Hillary William , Yu Xin , Richardet Tyler , Mercier Helen P. A. , Gerken Michael
Published: July 2012

The new compound (III) is synthesized by reaction of (I) and (II) (yield given in g) and directly from (IV) using the new sulfide‐transfer reagent (V).
ChemInform Abstract: A New Electronically Deficient Atropisomeric Diphosphine Ligand (S)‐CF3O‐BiPhep and Its Application in Asymmetric Hydrogenation.
Authors: Zhang De‐Yang , Yu Chang‐Bin , Wang Min‐Can , Gao Kai , Zhou Yong‐Gui
Published: July 2012

The biphenyl ligand is successfully applied to the hydrogenation of quinoline and indole derivatives.
ChemInform Abstract: A Carbaboranylmercuric Salt Catalyzed Reaction: Highly Regioselective Cycloisomerization of 1,3‐Dienes.
Authors: Yamamoto Hirofumi , Sasaki Ikuo , Shiomi Shinya , Yamasaki Naoto , Imagawa Hiroshi
Published: July 2012

The title salt efficiently promotes the formation of pyrrolidine, piperidine, indole, quinoline, isoquinoline, and tetrahydronaphthalene derivatives.
ChemInform Abstract: Catalyst‐Free Approach for Solvent‐Dependent Selective Oxidation of Organic Sulfides with Oxone.
Authors: Yu Bing , Liu An‐Hua , He Liang‐Nian , Li Bin , Diao Zhen‐Feng , Li Yu‐Nong
Published: July 2012

The oxidation of sulfides (I) with Oxone in ethanol leads to sulfoxides (II), while the oxidation in water affords sulfones (III) in high yields.
ChemInform Abstract: Iodine(III)‐Promoted Intermolecular Diamination of Alkenes.
Authors: Souto Jose A. , Gonzalez Yolanda , Iglesias Alvaro , Zian Debora , Lishchynskyi Anton , Muniz Kilian
Published: July 2012

The bis(mesyl)amines are conveniently deprotected by treatment with Red‐Al.
ChemInform Abstract: Novel Synthesis of 1,2,4‐Triazolophanes and 1,3,4‐Oxadiazolophanes: A Dieckmann Condensation Approach.
Authors: Chande Madhukar S. , Sajithkumar C. , Mondkar Hemant S. , Barve Pravin A. , Diwan Sachin
Published: July 2012

Symmetrical diesters containing triazole and oxadiazole units are subjected to Diekmann condensation to prepare title triazolophanes, e.g. (IV) and (VII), and oxadiazolophanes, e.g. (VI).
ChemInform Abstract: Efficient and Practical Transition Metal‐Free Catalytic Hydration of Organonitriles to Amides.
Authors: Tu Tao , Wang Zhixun , Liu Zelong , Feng Xike , Wang Qingyi
Published: July 2012

Potassium carbonate is an efficient catalyst for the microwave‐assisted conversion of nitriles (I) into amides (II) (23 examples).
ChemInform Abstract: A New Synthetic Route for the Preparation of β‐Acyloxy Mercaptans via the Addition of Thioacids to Epoxides.
Authors: Abbasi Mohammad
Published: July 2012

Ring‐opening of epoxides with thioacids in the presence of silica gel‐NEt3 combined catalyst yields S‐benzylated β‐acyloxy mercaptans after benzylation of the crude thiols intermediates.
ChemInform Abstract: Suzuki Cross‐Coupling Catalyzed by Palladium (II) Complexes Bearing 1‐Aryl‐3,4,5,6‐tetrahydropyrimidine Ligands.
Authors: Mao Pu , Yang Liangru , Xiao Yongmei , Yuan Jinwei , Liu Xiujun , Song Maoping
Published: July 2012

Novel monodentate imine complexes (I) are presented as highly efficient catalysts for the reaction.
ChemInform Abstract: Chiral Sulfoxide—Olefin Ligands: Tunable Stereoselectivity in Rh‐Catalyzed Asymmetric 1,4‐Additions.
Authors: Chen Guihua , Gui Jiangyang , Cao Peng , Liao Jian
Published: July 2012

The ligand E/Z geometry controls the absolute configuration of the product.
ChemInform Abstract: Synthesis of [60]Fullerene‐Fused Sultones via Sulfonic Acid Group Directed C—H Bond Activation.
Authors: Li Fei , Liu Tong‐Xin , Wang Guan‐Wu
Published: July 2012

The reaction involves cleavage of C—H and O—H bonds and formation of C—C and C—O bonds.
ChemInform Abstract: Synthesis and Chemistry of New Spiro‐Δ1‐pyrazoline.
Authors: Louhichi Nesrine , Houas Amel , Hamadi Naoufel Ben , Msaddek Moncef
Published: July 2012

Addition of diazopropane (II) to α‐arylidenepyrrolidinones and α‐arylidene‐γ‐butyrolactones (I) affords the monoadducts (III) in a regiospecific fashion.
ChemInform Abstract: Facile Synthesis of 2‐Alkyl/Aryloxy‐2H‐azirines and Their Application in the Synthesis of Pyrroles.
Authors: Qi Xinxin , Xu Xianxiu , Park Cheol‐Min
Published: July 2012

The pyrrole synthesis can also be performed in an intramolecular manner by tethering of an alkene group onto the starting material, cf.
ChemInform Abstract: Cyclic α‐Amino Acids as Precursors for Synthesis of 2‐Amino‐3‐hetarylpyrrolin‐4‐ones and Their Spiro Derivatives.
Authors: Dobrydnev Alexey V. , Volovnenko Tatyana A. , Volovenko Yulian M. , Palamarchuk Gennady V. , Shishkin Oleg V.
Published: July 2012

A facile route for the synthesis of hetarylpyrrolinones and corresponding spiro‐derivatives based on the reaction of N‐protected amino acids (I) with benzimidazolylacetonitriles (II) or thiazole analogues is developed.
ChemInform Abstract: Iodine‐Catalyzed Condensation of Isatin with Indoles: A Facile Synthesis of Di(indolyl)indolin‐2‐ones and Evaluation of Their Cytotoxicity.
Authors: Reddy B. V. Subba , Rajeswari N. , Sarangapani M. , Prashanthi Y. , Ganji Roopa Jones , Addlagatta Anthony
Published: July 2012

The title compounds (III) (15 examples) are smoothly obtained under mild reaction conditions and found to possess a strong and selective cytotoxicity against cancer cells.
ChemInform Abstract: Efficient Construction of Fused Indolines with a 2‐Quaternary Center via an Intramolecular Heck Reaction with a Low Catalyst Loading.
Authors: Zhao Lei , Li Ziyuan , Chang Lin , Xu Jinyi , Yao Hequan , Wu Xiaoming
Published: July 2012

The transformation is effective for 2,3‐disubstituted indoles.
ChemInform Abstract: Palladium‐ and Copper‐Catalyzed Cyclizations of Hydrazine‐Derived Ugi Products: Facile Synthesis of Substituted Indazolones and Hydroxytriazafluorendiones.
Authors: Welsch Sebastian , Kalinski Cedric , Umkehrer Michael , Ross Guenther , Kolb Juergen , Burdack Christoph , Wessjohann Ludger A.
Published: July 2012

A broad spectrum of Ugi four‐component products involving ortho‐halogenated benzoic acids and protected hydrazines is synthesized.
ChemInform Abstract: Synergistic Chiral Ion Pair Catalysts for Asymmetric Catalytic Synthesis of Quaternary α,β‐Diamino Acids.
Authors: Shi Shi‐Hui , Huang Fu‐Ping , Zhu Ping , Dong Zhen‐Wen , Hui Xin‐Ping
Published: July 2012

The reaction proceeds with high dia‐ and enantioselectivities using a combination of a chiral phosphate anion and silver cation as a catalytic system.
ChemInform Abstract: Solvent‐Free One‐Pot Synthesis of Sulfonephthaleins from Saccharin and Phenols.
Authors: Tillu V. H. , Dumbre D. K. , Borate H. B. , Wakharkar R. D. , Choudhary V. R.
Published: July 2012

The reaction proceeds via in situ generation of o‐sulfobenzoic anhydride and its subsequent acid‐catalyzed condensation with phenols.
ChemInform Abstract: Synthesis and Characterization of 5‐Heteroarylsulfanyl‐4‐aryl‐1,2,3‐selena/thiadiazoles.
Authors: Manikannan Ramaiyan , Shanmugaraja Masilamani , Manojveer Seetharaman , Muthusubramanian Shanmugam
Published: July 2012

The reaction of heteroarylthio substituted semicarbazones (I) and (III) with thionyl chloride and selenium dioxide affords the corresponding thia‐ (II) and selenadiazoles (IV), respectively.
ChemInform Abstract: Studies on Novel Synthetic Methodologies. Part 9. A Novel Route to Synthesis of Flavones from Salicylaldehyde and Acetophenone Derivatives.
Authors: Sashidhara Koneni V. , Kumar Manoj , Kumar Abdhesh
Published: July 2012

The alternative process involves formation of 2‐hydroxychalcones followed by oxidative cyclization in the presence of catalytic iodine.
ChemInform Abstract: Enantioselective Activation of Stable Carboxylate Esters as Enolate Equivalents via N‐Heterocyclic Carbene Catalysts.
Authors: Hao Lin , Du Yu , Lv Hui , Chen Xingkuan , Jiang Huishen , Shao Yaling , Chi Yonggui Robin
Published: July 2012

Arylacetic ester enolates, generated in situ, react with α,β‐unsaturated imines to afford highly substituted N‐tosyl dihydropyridinones.
ChemInform Abstract: An Efficient Synthesis of Novel 2,4‐Disubstituted Tetrahydroquinolines and Quinolines.
Authors: Devakaram Ruth , Black David StC. , Kumar Naresh
Published: July 2012

The reaction of cis‐azaflavon‐4‐ol (I) with aromatic alcohols affords 2,4‐disubstituted trans‐tetrahydroquinolines, which are of interest as alkaloid substructures.
ChemInform Abstract: Application of Dearomatization Strategy on the Synthesis of Furoquinolinone and Angelicin Derivatives.
Authors: Ye Yang , Zhang Li , Fan Renhua
Published: July 2012

The novel approach is based on a cyclization/addition/aromatization/lactamization sequence.
ChemInform Abstract: Preparation of Quinazolino[3,2‐a]quinazolines via a Palladium‐Catalyzed Three‐Component Reaction of Carbodiimide, Isocyanide, and Amine.
Authors: Qiu Guanyinsheng , He Yaohua , Wu Jie
Published: July 2012

Title reaction involves multiple bond formations in one‐pot through nucleophilic attack, isocyanide insertion, and C‐N coupling steps.
ChemInform Abstract: Synthesis of Phenazines by Cu‐Catalyzed Homocoupling of 2‐Halogen Anilines in Water.
Authors: Yu Lintao , Zhou Xiangge , Wu Di , Xiang Haifeng
Published: July 2012

Optimized conditions are elaborated for the title reaction where o‐iodoanilines give (significantly) higher yields compared to the o‐bromoanilines.
ChemInform Abstract: Ga(ClO4)3‐Catalyzed Synthesis of Quinoxalines by Cycloaddition of α‐Hydroxyketones and o‐Phenylenediamines.
Authors: Pan Fan , Chen Tang‐Ming , Cao Jia‐Jia , Zou Jian‐Ping , Zhang Wei
Published: July 2012

Quinoxalines are prepared under simple and mild conditions.
ChemInform Abstract: Improved Synthesis of 2‐Methoxyphenothiazine.
Authors: Ruan Jian‐Cheng , Zhang Tao , Wang Shuai , Liu Jin‐Qiang , Qian Chao , Chen Xin‐Zhi
Published: July 2012

Condensation of aniline (I) with resorcinol (II), subsequent O‐methylation of condensation product (III) and cyclization of (V) furnishes 2‐methoxyphenothiazine (VI) in an overall yield of 74%.
ChemInform Abstract: Anionic [4 + 3] Heteroannulation of 2‐Azidoacrylates: A Modular Synthesis of 2‐Benzazepin‐1‐ones.
Authors: Dinda Bidyut Kumar , Jana Amit Kumar , Mal Dipakranjan
Published: July 2012

The reaction also works with substituted phthalides, e.g. (VI).
ChemInform Abstract: Choline Chloride·2ZnCl2 Ionic Liquid: An Efficient and Reusable Catalyst for the Solvent Free Kabachnik—Fields Reaction.
Authors: Disale Shamrao T. , Kale Sandip R. , Kahandal Sandeep S. , Srinivasan Thandankorai G. , Jayaram Radha V.
Published: July 2012

An operationally simple procedure using a deep eutectic mixture as catalytic ionic liquid is presented for the one‐pot three‐component synthesis of α‐aminophosphonates.
ChemInform Abstract: Total Synthesis and Absolute Configuration of Nocardioazine B.
Authors: Wang Mingzhong , Feng Xiangyang , Cai Liangzhen , Xu Zhengshuang , Ye Tao
Published: July 2012

The absolute stereochemistry of naturally occurring norcardioazine B (I) is established by synthesis of its enantiomer.
ChemInform Abstract: The First Stereoselective Total Synthesis of (Z)‐Cryptomoscatone D2, a Natural G2 Checkpoint Inhibitor.
Authors: Reddy Gandolla Chinna , Balasubramanyam Penagaluri , Salvanna N. , Reddy Thummala Sreenivasulu , Das Biswanath
Published: July 2012

involving two consecutive Maruoka asymmetric allylation reactions and a ring closing metathesis as key steps
ChemInform Abstract: Structure and Properties of Iron Nitrosyl Complexes with Functionalized Sulfur‐Containing Ligands
Authors: Sanina N. A. , Aldoshin S. M.
Published: July 2012

Review: 210 refs.
ChemInform Abstract: Synthesis, Reactions with DNA, and Antitumor Activity of Platinum Complexes with Aminonitroxyl Radicals
Authors: Sen' V. D. , Terent'ev A. A. , Konovalova N. P.
Published: July 2012

Review: 40 refs.
ChemInform Abstract: Asymmetric Catalytic Carbon—Carbon Coupling Reactions via C—H Bond Activation
Authors: Yang Lei , Huang Hanmin
Published: July 2012

Review: ca. 100 refs.
ChemInform Abstract: Synthesis of Unsymmetrically meso‐Substituted Porphyrins
Authors: Plunkett S. , Senge M. O.
Published: July 2012

Review: 66 refs.
ChemInform Abstract: A Comprehensive History of Arynes in Natural Product Total Synthesis
Authors: Tadross Pamela M. , Stoltz Brian M.
Published: July 2012

Review: 189 refs.
ChemInform Abstract: Calix[n]arenes in Action, Useful Host—Guest Catalysis in Organic Chemistry
Authors: Simoes Juliana B. , da Silva Daniel L. , de Fatima Angelo , Fernandes Sergio A.
Published: July 2012

Review: 88 refs.
ChemInform Abstract: Looking for Treasure in Stereochemistry‐Land. A Path Marked by Curiosity, Obstinacy, and Serendipity.
Authors: Juaristi Eusebio
Published: July 2012

Review: ca. 150 refs.
ChemInform Abstract: Change of Caged Dynamics at Tg in Hydrated Proteins Found After Suppressing the Methyl Group Rotation Contribution
Authors: Ngai K. L. , Capaccioli S. , Paciaroni A.
Published: July 2012

Review: 69 refs.
ChemInform Abstract: Targeting Bacterial Toxins
Authors: Ivarsson Matthias E. , Leroux Jean‐Christophe , Castagner Bastien
Published: July 2012

Review: 236 refs.
ChemInform Abstract: Cyborg Cells: Functionalization of Living Cells with Polymers and Nanomaterials
Authors: Fakhrullin Rawil F. , Zamaleeva Alsu I. , Minullina Renata T. , Konnova Svetlana A. , Paunov Vesselin N.
Published: July 2012

Review: 73 refs.
ChemInform Abstract: Thiazole‐Based Organic Semiconductors for Organic Electronics
Authors: Lin Yuze , Fan Haijun , Li Yongfang , Zhan Xiaowei
Published: July 2012

Review: 117 refs.
The unsatisfactory ThinPrep® Pap Test™: Analysis of technical aspects, most common causes, and recommendations for improvement
Authors: Rosa Marilin , Pragasam Premila , Saremian Jinous , Aoalin Ana , Graf William , Mohammadi Amir
Published: July 2012

ThinPrep® preparation is a widely‐used method for processing gynecologic specimens due to the many advantages of the technique. However, the presence of blood, inflammation, and lubricant, among other factors, can significantly interfere with specimen adequacy. The aim of this study was to identify and overcome the most common reasons for unsatisfactory ThinPrep® Pap Test™ results in our laboratory. From October 2010 to January 2011, we reprocessed cases categorized as “unsatisfactory for evaluation” to determine whether reprocessing these specimens would impact the unsatisfactory rate. Reasons for unsatisfactory results were classified as: technical reasons, scant cellularity, and complete obscuring factors. Two hundred fifty‐three cases were initially classified as unsatisfactory. Of these, 226 cases were reprocessed. Ninety cases became satisfactory after reprocessing with an overall improvement of 40%. The most common reasons for unsatisfactory results were the presence of lubricant (96 cases), presence of blood (64 cases), and technical problems (33 cases). Cases affected by blood or technical issues showed a significant improvement after reprocessing (56.2% and 90.9%, respectively). However, unsatisfactory cases owed to the presence of lubricant showed a relatively low percentage of improvement (16.6%). The main reasons for unsatisfactory results, the presence of blood and lubricant, can be avoided in many cases if sampling is not performed during bleeding and if the use of lubricants is limited during sample collection. Our study showed that reprocessing of selected cases can improve the overall unsatisfactory rate and can potentially reduce the risk of missing significant lesions. Diagn. Cytopathol. 2013. © 2012 Wiley Periodicals, Inc.
Analysis of traffic congestion by considering merging on entry lines in transportation system
Authors: Hoshino Takahiro , Tsuboi Kazuhiro , Hamamatsu Yoshio
Published: July 2012

In a transportation system, a merging control strategy is necessary to avoid collisions between vehicles at a merging section with entry lines. In this study, under the assumption that each entry line is assigned time‐independent priority, we analyze traffic congestion with a stochastic model. A quantitative estimation of the congestion is successfully obtained in terms of the average queue length and the average queuing delay. On the basis of analytical results, we propose a control strategy that changes the priority periodically. Using simulation, it is clarified that the proposed control strategy gives arbitrary values of the queue length and the queuing delay on each line. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(8): 34‐43, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11374
A simple derivation of the right interactor for a tall transfer function matrix and its application to inner‐outer factorization
Authors: Kase Wataru
Published: July 2012

The interactor matrix plays several important roles in control systems theory. In this paper, we present a simple method of deriving a right interactor for tall transfer function matrices using the Moore‐Penrose pseudoinverse. As a result of the presented method, all zeros of the interactor lie at the origin. The method will be applied to inner‐outer factorization for strictly proper transfer function matrices. It will be shown that the stability of the interactor is necessary to calculate the factorization. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(8): 17‐25, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11387
Guanidinium vs. Ammonium Surfactants in Soft‐Templating Approaches: Nanostructured Silica and Zwitterionic i‐Silica from Complementary Precursor–Surfactant Ion Pairs
Authors: El Hankari Samir , Hesemann Peter
Published: July 2012

We investigated the behaviour of guanidinium and ammonium surfactants as structure‐directing agents in template‐directed hydrolysis/polycondensation processes. For this purpose, a series of guanidinium surfactants was synthesised from long‐chain‐substituted primary amines. In a first series of experiments, we compared nanostructured silicas obtained by means of template‐directed hydrolysis/polycondensation reactions of TEOS in the presence of either guanidinium‐ or ammonium‐based surfactants. We observed that typical MCM‐41‐type silicas displaying a 2D hexagonal architecture were obtained in the presence of ammonium surfactants such as cetyltrimethylammonium bromide (CTAB). In contrast, the use of guanidinium surfactants led to the formation of hollow silica spheres or spherical silica nanoparticles. Secondly, we investigated the use of ammonium and guanidinium surfactants in the formation of periodic mesoporous organosilicas containing ionic groups (i‐silica). In particular, we studied template‐directed hydrolysis/polycondensation reactions of zwitterionic ammonium sulfonate and ammonium carboxylate precursors. We observed that both reactions involving the ammonium sulfonate precursor yielded structured i‐silicas. In contrast, hydrolysis/polycondensation reactions of the ammonium carboxylate precursor afforded structured materials only in the presence of the guanidinium surfactant, whereas amorphous materials were obtained in the presence of CTAB. This result reflects specific surfactant–precursor interactions and suggests that the nature of both surfactant and precursor determine the formation of i‐silica materials displaying regular architectures on a mesoscopic length scale.
Synthesis of Carbazole‐Type D‐π‐A Fluorescent Dyes Possessing Solid‐State Red Fluorescence Properties
Authors: Ooyama Yousuke , Sugiyama Tetsuya , Oda Yuichiro , Hagiwara Yuta , Yamaguchi Naoya , Miyazaki Eigo , Fukuoka Hiroshi , Mizumo Tomonobu , Harima Yutaka , Ohshita Joji
Published: July 2012

Carbazole‐type donor‐π‐acceptor (D‐π‐A) fluorescent dyes (SO1 and SO2), each containing a diphenylamino system as an electron‐donating group and a nitro moiety as an electron‐accepting group, have been designed and synthesized, and their photophysical properties in solution and in the solid state have been investigated. The absorption and fluorescence properties of SO1 and SO2 in solution are similar, and both dyes exhibited moderate fluorescence quantum yields. In the solid state, however, the dye SO2, with a butyl substituent on the carbazole ring, exhibited red fluorescence at around 620 nm, whereas the dye SO1, with no substituent on the carbazole ring, did not exhibit these solid‐state fluorescence properties. Furthermore, the dye SO2 exhibited weak mechanofluorochromic (MFC) properties: grinding of as‐recrystallized dyes induces slight bathochromic shifts of the fluorescence excitation and emission maxima. To elucidate the effects of molecular and crystal structures on the solid‐state fluorescence properties, we performed semiempirical molecular orbital calculations (PM3 and INDO/S) and single‐crystal X‐ray structural analysis. The X‐ray crystal structures of SO1 and SO2 demonstrated that a continuous intermolecular π‐stacking between the fluorophores was observable in the crystal structure of SO1, but not in that of SO2. The MO calculations revealed that SO1 and SO2 have similarly large dipole moments in the ground state (μg ≈ 8 D). The relationship between the observed solid‐state photophysical properties and the molecular and crystal structures of the carbazole‐type D‐π‐A fluorescent dyes are discussed on the basis of experimental results and MO calculations. It is found that the formation of a continuous intermolecular π‐stacking between the fluorophores causes a drastic fluorescence quenching in the solid state and that D‐π‐A fluorescent dyes with very large dipole moments can reduce the MFC properties, due to strong dipole–dipole interactions between the fluorophores in the solid state.
Total Synthesis of Calothrixins A and B by Palladium‐Catalyzed Tandem Cyclization/Cross‐Coupling Reaction of Indolylborate
Authors: Abe Takumi , Ikeda Toshiaki , Choshi Tominari , Hibino Satoshi , Hatae Noriyuki , Toyata Eiko , Yanada Reiko , Ishikura Minoru
Published: July 2012

The palladium‐catalyzed tandem cyclization/cross‐coupling reaction of triethyl(indol‐2‐yl)borate with vinyl bromide was successfully used in the concise total synthesis of the indolophenanthridine alkaloids, calothrixins A and B.
Influencing the Balance between ipso and ω Nucleophile Addition to (1‐Arylcyclohexadienyl)iron Intermediates in Alkaloid Synthesis
Authors: Stephenson G. Richard , Anson Christopher E. , Malkov Andrei V. , Roe Caroline
Published: July 2012

Aryllithium reagents react with tricarbonyl(η5‐1,4‐dimethoxycyclohexadienyl)iron hexafluorophosphate to give η4 products, which are converted into a series of (1‐arylcyclohexadienyl)iron(1+) complexes with H, CHO, CH2OAc, and CH(OAc)2 on the arene, ortho to the point of attachment to the dienyl ligand. The structures of these complexes have been compared by X‐ray crystallography. Correlations between spectroscopic and structural data indicate that the crystallographically defined conformations are also significant in the interpretation of the pathways of nucleophile addition in solution. Reactions with nucleophiles are influenced by the conformational properties of the 1‐aryl substituent, and examples of ω addition and a new intramolecular ipso addition relative to the arene have been characterised. Intermolecular ipso addition has been used to synthesise the alkaloid mesembrine in which 3,4‐dimethoxy electron‐donating substituents flatten the arylcyclohexadienyl portion and facilitate the ipso pathway. Electron‐withdrawing formyl substituents cause the arene to adopt a more perpendicular conformation, and a through‐space interaction between CHO and the exo face of the cationic dienyliron complex activates the aldehyde for reaction with (PhC≡C)2CuLi, generating an alkoxide that forms a spirocyclic ether by intramolecular reaction with the aryl‐substituted terminus of the dienyl ligand. Full spectroscopic assignments of the (1‐arylcyclohexadienyl)iron(1+) complexes are reported and correlated with structural data from crystallography to show that the complexes fall into two groups in terms of the relationship between the dihedral angle of the arene and the dienyl systems and the weighted means for ν(CO) in their infrared spectra. The relationship between this structural data, the distribution of positive charge on the dienyliron complex, and the regioselectivity of nucleophile addition explains how the correct choice of substitution patterns influences the selectivity between ipso and ω reactivity in 1,1‐iterative strategies that use (1‐arylcyclohexadienyl)iron(1+) complexes as key building blocks in synthetic routes to the galanthamine and crinine subclasses of the Amaryllidaceae alkaloids.
First Total Syntheses of Oresbiusins A and B, Their Antipodes, and Racemates: Configuration Revision and Anti‐HIV Activity
Authors: Hwu Jih Ru , Varadaraju Tirumala G. , Abd‐Elazem Ibrahim S. , Huang Ru Chih C.
Published: July 2012

The first total syntheses of oresbiusin A in the (+)‐, (–)‐, and (±)‐forms were accomplished in five steps with overall yields of ca. 70 %. The key intermediates with optical activity were generated through a Sharpless asymmetric dihydroxylation reaction. These efforts allowed us to establish the absolute configuration of this natural product with dextrorotary and a 2S configuration. In addition, the total syntheses of both enantiomers of oresbiusin B along with its racemate were accomplished in six steps with overall yields of 58 %. Among these compounds, the unnatural oresbiusin A with a levorotary rotation was found to possess dose dependent anti‐HIV‐1 activity in H9 cells, whereas the other compounds were inactive.
Performance assessment of tall concrete core‐wall building designed using two alternative approaches
Authors: Yang T. Y. , Moehle J. P. , Bozorgnia Y. , Zareian F. , Wallace J. W.
Published: July 2012

Concrete core‐wall structural systems are prevalent for high‐rise residential buildings in the West Coast of the United States. To assess the seismic performance characteristics of this system, a 42‐story core‐wall residential building was designed for a site in Los Angeles, CA. The building was designed using two different design approaches. The first design followed prescriptive requirements of US building codes, except height limits were disregarded. The second design followed a performance‐based procedure. Analytical models of each design were subjected to a series of earthquake ground motions representative of very frequent to very rare shaking intensities. Effectiveness of the various design methods is assessed considering structural performance indices, initial costs, and repair costs associated with anticipated earthquake ground shaking. The results illustrate the seismic performance potential of this structural system and demonstrate the application of a practical seismic performance assessment approach for buildings. Copyright © 2012 John Wiley & Sons, Ltd.
A silviculture application of the glyphosate-based herbicide VisionMAX to wetlands has limited direct effects on amphibian larvae
Authors: Edge Christopher B. , Thompson Dean G. , Hao Chunyan , Houlahan Jeff E.
Published: July 2012

Herbicides are commonly used in agriculture and silviculture to reduce interspecific competition among plants and thereby enhance crop growth, quality, and volume. Internationally, glyphosate-based herbicides are the most widely used herbicides in both of these sectors. Laboratory and mesocosm studies have demonstrated that some formulations are toxic to amphibian larvae below concentrations that approximate predicted maximal or “worst-case” exposure scenarios. However, field studies have not found evidence of toxicity at these concentrations. The authors conducted a replicated field experiment involving 10 naturalized wetlands split in half with an impermeable plastic barrier to assess the direct toxicity of a glyphosate formulation commonly used in silviculture (VisionMAX™). The herbicide formulation was applied directly to the surface of one side of each wetland at one of two target aqueous exposure rates (high = 2,880, low = 550 µg acid equivalents [a.e.]/L), and the other side was left as an untreated control. The survival and growth of green frog larvae (Lithobates clamitans) were assessed for two years following herbicide treatment. The herbicide did not have a negative impact on survival or growth of L. clamitans larvae at either treatment level. In fact, mean larval abundance was typically greater in the treated sides than in control sides within the year of herbicide application. These results indicate that typical silviculture use of VisionMAX poses negligible risk to larval amphibians, likely because the combined effects of sorption and degradation in natural wetlands limit the exposure magnitude and duration. Environ. Toxicol. Chem. 2012; 31: 2375–2383. © 2012 SETAC
How are trace elements mobilized during the postweaning fast in Northern elephant seals?
Authors: Habran Sarah , Crocker Daniel E. , Debier Cathy , Das Krishna
Published: July 2012

Northern elephant seal (Mirounga angustirostris) pups undergo a substantial intertissue reorganization of protein, minerals, and other cellular components during their postweaning development, which might entail the mobilization of associated contaminants. The authors investigated the changes in concentrations of 11 elements (Ca, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Se, V, and Zn) in a longitudinal study on 22 northern elephant seal pups during the postweaning fast. Slight changes in most element concentrations were observed in blood throughout the fast. Circulating levels of Hg, Se, and Cu appeared less altered during the postweaning fast than measured during suckling. Despite the considerable fat utilization, element concentrations, except Fe, in blubber remained stable throughout the fast, which suggests that elements are mobilized from blubber as efficiently as lipids. As indicators of the placental transfer, concentrations in lanugo hair revealed the existence of maternal transfer and accumulation of all assayed trace elements during fetal development. In addition, the new pelage, rapidly produced after weaning, appeared to be an important elimination route for toxic metals such as Hg, Cd, and Pb. The high mineral content detected in pup hair suggests that this species would be more exposed to trace elements than other phocids (except Cd and Pb). Nevertheless, this statement needs further monitoring and toxicological studies to determine better the exposition to trace elements and its potential impact on the health of the northern elephant seal. Environ. Toxicol. Chem. 2012; 31: 2354–2365. © 2012 SETAC
Resveratrol‐mediated apoptosis of hodgkin lymphoma cells involves SIRT1 inhibition and FOXO3a hyperacetylation
Authors: Frazzi Raffaele , Valli Riccardo , Tamagnini Ione , Casali Bruno , Latruffe Norbert , Merli Francesco
Published: July 2012

Resveratrol (RSV), a plant‐derived stilbene, induces cell death in Hodgkin lymphoma (HL)‐derived L‐428 cells in a dose‐dependent manner (IC50 = 27 μM, trypan blue exclusion assay). At a lower range (25 μM), RSV treatment for 48 hr causes arrest in the S‐phase of the cell cycle, while at a higher concentration range (50 μM), apoptosis can be detected, with activation of caspase‐3. The histone/protein deacetylase SIRT1 has been described as a putative target of RSV action in other model systems, even though its role in cancer cells is still controversial. Here we show that RSV, at both concentration ranges, leads to a marked increase in p53, while a decrease of SIRT1 expression level, as well as enzyme activity, only occurred at the higher concentration range. Concomitantly, however, treatments at both concentration ranges resulted in a marked increase in K373‐acetylated p53 and lysine‐acetylated FOXO3a. Immunohistochemical stainings of human lymph nodes show a preferential distribution of SIRT1 in the germinal center of the follicles while the mantle zone shows nearly no staining to few positive cells. The classical HL‐affected lymph nodes show a strong positivity of the diagnostic Hodgkin Reed‐Sternberg cells. Notably, both the HL‐derived cell lines and the Hodgkin Reed‐Sternberg cells of the affected lymph nodes derive from germinal center‐derived B cells. The study of SIRT1 distribution and expression on a larger number of biopsies might disclose a novel role for this histone/protein deacetylase as therapeutic target.
Monitoring rhizospheric pH, oxygen, and organic acid dynamics in two short‐time flooded plant species
Authors: Schreiber Christina M. , Zeng Bo , Blossfeld Stephan , Rascher Uwe , Kazda Marian , Schurr Ulrich , Höltkemeier Agnes , Kuhn Arnd J.
Published: July 2012

The rhizosphere of two flooding‐resistant plant species (Arundinella anomala Steud., Alternanthera philoxeroides Mart.) from Three Gorges Reservoir area (China) has been examined for reactions to waterlogging and submergence. Rhizosphere parameters were monitored in natural sediment substrate by means of a dual‐access floodable rhizobox, which allows monitoring of oxygen and pH dynamics noninvasively with planar optodes in high temporal and spatial resolution, as well as simultaneous low‐invasive soil‐solution sampling. Analysis of samples for low‐molecular‐weight organic acids (LMWOA) was done by capillary electrophoresis. Roots could be observed easily in situ during growth and exposure to flooding. The floodable rhizobox is therefore considered a valuable tool for root‐reaction monitoring also under flooding conditions. During waterlogging, both species exuded oxygen into their rhizosphere and showed diurnal rhythms of rhizospheric acidification. The pH of the rhizosphere of growing root tips decreased up to 0.8 units corresponding to higher LMWOA concentrations. These rhythms weakened during flooding, but gained maximum amplitude again rapidly after resurfacing. We conclude that the root system was still fully functioning during and after flooding, and that flooding poses no threat to the physiology of the root system of the study species.
Effect of sampling density on regional soil organic carbon estimation for cultivated soils
Authors: Sun Weixia , Zhao Yongcun , Huang Biao , Shi Xuezheng , Landon Darilek Jeremy , Yang Jinsong , Wang Zhigang , Zhang Beier
Published: July 2012

An extensive knowledge of how sampling density affects soil organic C (SOC) estimation at regional scale is imperative to reduce uncertainty to a meaningful confidence level and aid in the development of sampling schemes that are both rational and economical. Using kriging prediction, this paper examined the effect of sampling density on regional SOC‐concentration estimations in cultivated topsoils at six scales in a 990 km2 area of Yucheng County, a typical region in the N China Plain. Except the original data set (n = 394), five other sampling densities were recalculated using grids of 8 km × 8 km (n = 28), 8 km × 4 km (n = 44), 4 km × 4 km (n = 82), 4 km × 2 km (n = 142), and 2 km × 2 km (n = 257), respectively. Experimental SOC semivariances and kriging interpolations at six sampling density scales were calculated and modeled to estimate regional SOC variability. Accuracy of the effects of the five sampling densities on regional SOC estimations was assessed using the indices of mean error (ME) and root mean square error (RMSE) with 100 independent validation samples. By comparison with the kriged grid map derived from the 394 samples data set, the relative error (RE,%) was spatially calculated to highlight the spatial variability of prediction errors at five sampling‐density scales due to the intrinsic limitations of ME and RMSE in accuracy assessment. The results indicated that sampling density significantly affected the estimation of regional SOC concentration. Particularly when the sampling density was < 4 km × 4 km, the large spatial variation of SOC was concealed. Semivariance analysis indicated that different sampling density had significant effect on reasonable detection of the dominant factors which influenced SOC spatial variation. Greater sampling density could more exactly reveal regional SOC variation caused by human management. The prediction accuracy for regional SOC estimation increased with the increasing of sampling density. The critical areas with larger RE values should be intensified in the future sampling scheme, and the areas of lower RE values should be decreased relatively. A specific sampling scheme should be considered in accordance with the demand to the estimation accuracy of regional SOC stock at a certain confidence level. Our results will facilitate a better understanding of the effect of sampling density on regional SOC estimation for future sampling schemes by providing meaningful confidence levels.