bluuebunny/crossref_metadata_2025_split huggingface dataset:
Women's human rights violations: Cameroonian students' perceptions
Authors: Kassea Raul , Sakki Inari , Pirttilä‐Backman Anna‐Maija 
Published: January 2009

AbstractCameroonian university students (N = 666) assessed whether certain different societal positions that the law grants to women and men (the husband chooses the marital home, the husband wields parental power, a married woman cannot freely engage in trade, the husband administers his wife's personal property) and certain cultural practices (female genital mutilation, parents arranging their children's marriage) were seen as violations of women's human rights. Justifications for the choices were also analysed. Female genital mutilation was most often seen as a violation of women's human rights, and the husband selecting the marital home was least often seen as a violation. These differences were explained by cultural specificities. Women more often than men saw the cases as violations of rights. Respondents coming from the North saw the cases less often as violations of rights than respondents from other geocultural areas, which was in accordance with their previously observed higher collectivism. Copyright © 2009 John Wiley & Sons, Ltd.
“Helter‐Skelter‐Like” Perylene Polyisocyanopeptides
Authors: Schwartz Erik , Palermo Vincenzo , Finlayson Chris E. , Huang Ya‐Shih , Otten Matthijs B. J. , Liscio Andrea , Trapani Sara , González‐Valls Irene , Brocorens Patrick , Cornelissen Jeroen J. L. M. , Peneva Kalina , Müllen Klaus , Spano Frank C. , Yartsev Arkady , Westenhoff Sebastian , Friend Richard H. , Beljonne David , Nolte Roeland J. M. , Samorì Paolo , Rowan Alan E. 
Published: January 2009

AbstractExciton migration! Spectroscopic analyses and extensive molecular dynamics studies revealed a well‐defined 41 helix in which the perylene molecules (see figure) form four “helter‐skelter‐like” overlapping pathways along which excitons and electrons can rapidly migrate.magnified imageWe report on a combined experimental and computational investigation on the synthesis and thorough characterization of the structure of perylene‐functionalized polyisocyanides. Spectroscopic analyses and extensive molecular dynamics studies revealed a well defined 41 helix in which the perylene molecules form four “helter skelter‐like” overlapping pathways along which excitons and electrons can rapidly migrate. The well‐defined polymer scaffold stabilized by hydrogen bonding, to which the chromophores are attached, accounts for the precise architectural definition, and molecular stiffness observed for these molecules. Molecular‐dynamics studies showed that the chirality present in these polymers is expressed in the formation of stable right‐handed helices. The formation of chiral supramolecular structures is further supported by the measured and calculated bisignated Cotton effect. The structural definition of the chromophores aligned in one direction along the backbone is highlighted by the extremely efficient exciton migration rates and charge densities measured with Transient Absorption Spectroscopy.
B Values as a Sensitive Measure of Steric Effects
Authors: Ruzziconi Renzo , Spizzichino Sara , Lunazzi Lodovico , Mazzanti Andrea , Schlosser Manfred 
Published: January 2009

AbstractSomeone who says “A” should be prepared to also say “B”: In contrast to cyclohexane model‐based A values, biphenyl model‐derived B values are powerful tools to quantify steric repulsion in and conformational behavior of ortho‐substituted aromatic compounds.magnified imageTorsional barriers of 15 ortho‐substituted biphenyls have been determined computationally using the B3LYP density functional and experimentally by variable‐temperature (“dynamic”) nuclear magnetic resonance. Taking advantage of the 3′‐isopropyldimethylsilyl group as a novel and superior diastereotopicity probe and tracking coalescence temperatures down to −173 °C (100 K), activation energies of aryl–aryl rotation as small as 5 kcal mol−1 can be assessed. The 2‐X/2′‐H repulsion increments thus derived are powerful parameters for rationalizing and predicting the conformational behavior of aromatic compounds carrying ortho substituents.
Enantioselective Friedel–Crafts Alkylation of Indoles with Alkylidene Malonates Catalyzed by N,N′‐Dioxide–Scandium(III) Complexes: Asymmetric Synthesis of β‐Carbolines
Authors: Liu Yanling , Shang Deju , Zhou Xin , Liu Xiaohua , Feng Xiaoming 
Published: January 2009

AbstractAn efficient catalytic asymmetric Friedel–Crafts alkylation of indoles with alkylidene malonates has been developed by using a chiral N,N′‐dioxide–Sc(OTf)3 complex as the catalyst (see scheme). Some optically active intermediates containing the indole skeleton have been synthesized, such as indolepropionic acid, tryptamines, and β‐carbolines. The coordination between the scandium atom and the chiral N,N′‐dioxide compound has been revealed by X‐ray structure analysis.magnified image
Organocatalytic Domino Michael–Knoevenagel Condensation Reaction for the Synthesis of Optically Active 3‐Diethoxyphosphoryl‐2‐oxocyclohex‐3‐enecarboxylates
Authors: Albrecht Łukasz , Richter Bo , Vila Carlos , Krawczyk Henryk , Jørgensen Karl Anker 
Published: January 2009

AbstractVersatile dominoes: A novel, organocatalytic, Michael–Knoevenagel condensation domino reaction of ethyl 4‐diethoxyphosphoryl‐3‐oxobutanoate with various aryl‐ and aliphatic‐substituted α,β‐unsaturated aldehydes catalyzed by a chiral diarylprolinol ether has been successfully performed. The reaction proceeds in a highly enantio‐ and diastereoselective manner giving access to optically active 6‐substituted‐3‐diethoxyphosphoryl‐2‐oxocyclohex‐3‐enecarboxylates (see scheme).magnified imageA novel, organocatalytic, highly enantio‐ and diastereoselective synthetic approach towards optically active 6‐substituted‐3‐diethoxyphosphoryl‐2‐oxocyclohex‐3‐enecarboxylates is presented. Our methodology utilizes a Michael–Knoevenagel domino reaction sequence of ethyl 4‐diethoxyphosphoryl‐3‐oxobutanoate and α,β‐unsaturated aldehydes catalyzed by a chiral diarylprolinol ether. The cyclohexenecarboxylates obtained are particularly well suited for the preparation of highly functionalized cyclohexene and cyclohexane derivatives, with up to four chiral centers and high levels of stereocontrol.
Iron‐Catalyzed Ligand‐Free Three‐Component Coupling Reactions of Aldehydes, Terminal Alkynes, and Amines
Authors: Li Pinhua , Zhang Yicheng , Wang Lei 
Published: January 2009

AbstractA tri‐umph in many respects: The iron‐catalyzed ligand‐free, one‐pot three‐component coupling reactions of aldehydes, terminal alkynes, and amines in the presence of 4 A molecular sieves yields the corresponding propargylamines in good to excellent yields, displays a broad substrate scope, and is economical and environmentally friendly (see scheme).magnified image
Cover Picture: The Chemistry of Escapin: Identification and Quantification of the Components in the Complex Mixture Generated by an L‐Amino Acid Oxidase in the Defensive Secretion of the Sea Snail Aplysia californica (Chem. Eur. J. 7/2009)
Authors: Kamio Michiya , Ko Ko‐Chun , Zheng Shilong , Wang Binghe , Collins Stacy L. , Gadda Giovanni , Tai Phang C. , Derby Charles D. 
Published: January 2009

AbstractDefensive chemicals such as the ink secretion of this marine gastropod mollusk—the sea hares Aplysia californica—are released following attacks from predators for protection. One might expect these secretions to be complex mixtures of products, given that they must work against a diversity of predators. In their Full Paper on page 1597 ff., C. D. Derby et al. describe some of the chemical complexity of the ink of sea hares attributable to the enzyme “escapin”. Escapin is an L‐amino acid oxidase that oxidatively deaminates its major substrate, L‐lysine, to produce an equilibrium mixture of the molecules shown in this image. Photograph from Genny Anderson (Santa Barbara City College).magnified imageNo Abstract
Der Beitrag zur Sicherheit verfahrenstechnischer Anlagen des DECHEMA/GVC‐Forschungsausschusses „Sicherheitstechnik in Chemieanlagen”︁
Authors: Pilz V. 
Published: January 2009

AbstractDer DECHEMA/GVC‐Forschungsausschuss Sicherheitstechnik in Chemieanlagen war in den vergangenen 30 Jahren seit seiner Gründung an nahezu allen sicherheitstechnischen Entwicklungen beteiligt. Die Fachgemeinschaft hat die erforderliche Forschung gefördert, das Wissen unter Fachleuten verbreitet sowie politischen Gremien zugearbeitet. Heutzutage ist die Sicherheit verfahrenstechnischer Anlagen wesentlich transparenter und das Sicherheitsmanagement erheblich systematischer. Jetzt liegt der Fokus der Weiterentwicklung daher eher auf der Nutzung von interdisziplinärem Wissen zur Entwicklung neuer Sicherheitskonzepte, um eine Optimierung von Produktivität und Sicherheit gleichermaßen zu erreichen. Der Forschungsausschuss wird auch zukünftig dafür Sorge tragen, dass sich die Sicherheit von Chemieanlagen ständig weiter entwickelt.
Europäisches Recht in der physikalisch‐chemischen Sicherheitstechnik: Beispiele in Verordnungen, Richtlinien und Normen
Authors: Bothe rer. nat. H. , Schendler T. 
Published: January 2009

AbstractGrundlegende Anforderungen des Brand‐ und Explosionsschutzes im weitesten Sinn und entsprechende sicherheitstechnische Standards werden in europäischen Richtlinien und Normen beschrieben. Der Beitrag skizziert beispielhaft aktuelle Entwicklungen und in einigen Fällen deren Auswirkungen auf das entsprechende nationale Regelwerk.
Sicherheit in der Mikroreaktionstechnik
Authors: Gödde Markus , Liebner Christian , Hieronymus Hartmut 
Published: January 2009

AbstractDie Mikroverfahrenstechnik beschäftigt sich mit Apparaten, deren innere Abmessungen kleiner als ein Millimeter sind. Mikroreaktoren sind zurzeit Gegenstand intensiver Forschungsarbeit. Aus Sicht der chemischen Sicherheitstechnik besteht eines von mehreren Zielen bei der Entwicklung von Mikroreaktoren darin, schwer beherrschbare Reaktionen bei Reaktionsbedingungen zu realisieren, die in konventionellen Chemieanlagen wegen ihrer besonderen Gefährlichkeit nicht mehr beherrscht werden können. Der große spezifische Wärmeaustausch kann das thermische Durchgehen der Reaktion verhindern, die engen Abmessungen können die Ausbreitung von Explosionen unterdrücken. Bei mehrstufigen Synthesen kann die Lagerung giftiger oder zersetzungsfähiger Zwischenprodukte durch unverzügliche weitere Umsetzung in einem folgenden Reaktionsschritt vermieden werden. Der vorliegende Beitrag widmet sich sicherheitstechnischen Aspekten der Mikroverfahrenstechnik.
Temperaturen und Funkenentstehung bei Trockenreibung zwischen metallischen Reibpartnern
Authors: Ott T. , Welzel F. , Beyer M. , Klages C.‐P. 
Published: January 2009

AbstractBei Fehlfunktionen von explosionsgeschützten mechanischen Geräten kann eine reibende Berührung von sich gegeneinander bewegenden Teilen nicht ausgeschlossen werden. Erreicht die Kontaktzone eine hinreichend hohe Temperatur, können die abgetragenen Partikel mit dem Luftsauerstoff verbrennen. Sowohl die hohen Oberflächentemperaturen als auch die mechanischen Funken sind dabei mögliche potenzielle Zündquelle für explosionsfähige Atmosphären.
Neural organization of first optic neuropils in the littoral crab Hemigrapsus oregonensis and the semiterrestrial species Chasmagnathus granulatus
Authors: Sztarker Julieta , Strausfeld Nicholas , Andrew David , Tomsic Daniel 
Published: January 2009

AbstractCrustaceans are among the most extensively distributed arthropods, occupying many ecologies and manifesting a great variety of compound eye optics; but in comparison with insects, relatively little is known about the organization and neuronal morphologies of their underlying optic neuropils. Most studies, which have been limited to descriptions of the first neuropil—the lamina—suggest that different species have approximately comparable cell types. However, such studies have been limited with regard to the types of neurons they identify and most omit their topographic relationships. It is also uncertain whether similarities, such as they are, are independent of visual ecologies. The present account describes and compares the morphologies and dispositions of monopolar and other efferent neurons as well as the organization of tangential and smaller centrifugal neurons in two grapsoid crabs, one from the South Atlantic, the other from the North Pacific. Because these species occupy significantly disparate ecologies we ask whether this might be reflected in differences of cell arrangements within the most peripheral levels of the visual system. The present study identifies such differences with respect to the organization of centrifugal neurons to the lamina. We also identify in both species neurons in the lamina that have hitherto not been identified in crustaceans and we draw specific comparisons between the layered organization of the grapsoid lamina and layered laminas of insects. J. Comp. Neurol. 513:129–150, 2009. © 2009 Wiley‐Liss, Inc.
Involvement of R‐type Ca2+ channels in neurotransmitter release from spinal dorsolateral funiculus terminals synapsing motoneurons
Authors: Castro Alberto , Andrade Arturo , Vergara Paula , Segovia Jose , Aguilar Justo , Felix Ricardo , Delgado‐Lezama Rodolfo 
Published: January 2009

AbstractMolecular studies have revealed the presence of R‐type voltage‐gated Ca2+ channels at pre‐ and postsynaptic regions; however, no evidence for the participation of these channels in transmitter release has been presented for the spinal cord. Here we characterize the effects of SNX‐482, a selective R channel blocker, on the monosynaptic excitatory postsynaptic potentials (EPSPs) evoked in motoneurons by stimulation of dorsolateral funiculus (DLF) terminals in a slice preparation from the adult turtle spinal cord. SNX‐482 inhibited neurotransmission in a dose‐dependent manner, with an IC50 of ∼9 ± 1 nM. The EPSP time course and membrane time constant of the motoneurons were not altered, suggesting a presynaptic mechanism. The toxin inhibited the residual component of the EPSPs recorded in the presence of N‐ and P/Q‐type Ca2+ channel blockers, strongly suggesting a role for the R channels in neurotransmission at the spinal cord DLF terminals. Consistently with this, RT‐PCR analysis of turtle spinal cord segments revealed the expression of the CaV2.3 pore‐forming (α1E) subunit of R channels, whereas the use of anti‐α1E‐specific antibodies resulted in its localization in the DLF fibers as demonstrated by immunohistochemistry coupled with laser confocal microscopy. J. Comp. Neurol. 513:188–196, 2009. © 2009 Wiley‐Liss, Inc.
Growth and characterization of thiourea mixed cadmium – lead chloride – a nonlinear optical crystal
Authors: Nagarajan K. , Raman S. Kumara , Sundaram R. 
Published: January 2009

AbstractNonlinear optical (NLO) crystal of thiourea mixed cadmium–lead chloride dihydrate Cd[(PbCl3)(NH2CSNH2)].2H2O (TCCPC) have been grown in solution by slow evaporation technique at room temperature. The powder X‐ray diffraction pattern has been recorded and indexed. The UV‐Vis‐NIR transmittance and FT‐IR spectrum have been recorded in the range 200‐1090 nm and 400‐4000 cm‐1, respectively. The lower cut‐off wavelength is 280 nm in the UV region, which is higher than that of pure Cd(PbCl3) (CCPC) crystal. The presence of functional groups has been confirmed by FT‐IR analysis. The TCCPC crystal was characterized by SEM and EDX spectrum. The second harmonic generation (SHG) of the thiourea mixed cadmium–lead chloride (TCCPC) crystal is demonstrated by the Kurtz Perry method using Nd:YAG laser and the results confirm that the grown crystal is roughly three times more efficient than ADP. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal structure and characterization of a novel organic optical crystal: 4‐chloro‐3‐nitrobenzophenone
Authors: Babu G. Anandha , Thirupugalmani K. , Ramasamy P. , Ravikumar K. 
Published: January 2009

AbstractSingle crystals of a novel organic material, 4‐Chloro‐3‐Nitrobenzophenone (4C3N) were grown from acetone solution employing the technique of controlled evaporation. 4C3N belongs to the Orthorhombic system, with a = 12.9665(11) Å, b = 7.4388(6) Å, c = 24.336(2) Å, α = β = γ = 90°. FT‐IR study has been performed to identify the functional groups. The transmittance of 4C3N has been used to calculate the refractive index n; the extinction coefficient K and both the real εr and imaginary εi components of the dielectric constant as functions of photon energy. The optical band gap of 4C3N is 2.7 eV. Thermo gravimetric analysis and differential thermal analysis have also been carried out, and the thermal behavior of 4C3N crystal has been studied. The mechanical properties have been investigated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Conversion from ZnO nanospindles into ZnO/ZnS core/shell composites and ZnS microspindles
Authors: Li Fei , Liu Xueqin , Kong Tao , Li Zhen , Huang Xintang 
Published: January 2009

AbstractThe formation process of ZnO/ZnS core/shell microcomposites and ZnS microspindles prepared by the reaction of ZnO colloids and thioacetamide under hydrothermal conditions was investigated in detail by X‐ray powder diffraction, field emission scanning electron microscopy, transmission electron microscopy and selected‐area electron diffraction techniques. The precursors of spindlelike ZnO colloids were prepared by a hydrothermal method with the help of a surfactant. A growth mechanism was proposed to account for the formation of ZnO/ZnS core/shell microcomposites and ZnS microspindles. Luminescence measurement revealed that ZnO/ZnS core/shell microcomposites integrated the luminescence effect of ZnO and ZnS. The blue and green emissions were dramatically enhanced, while the orange emission disappeared. The results provide a good approach to tune the visible emission of the ZnO nanostructures by ZnS coating. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Factors affecting the formation of misoriented domains in 6H‐SiC single crystals grown by PVT method
Authors: Peng T. H. , Yang H. , Jian J. K. , Wang W. J. , Wang W. Y. , Chen X. L. 
Published: January 2009

AbstractMisoriented domains (MDs) are common defects in 6H‐SiC single crystals. We performed an experimental study on the formation of MDs in 2‐inch 6H‐SiC single crystals. Micro‐Raman spectroscopy revealed that the polytype of MDs was mainly 4H‐SiC. By changing growth conditions, it was found that the MDs' formation was closely related to growth rate and the position of highest temperature relative to growth interface. When the growth rate of ingots was relatively high the MDs were more likely to form. Furthermore, the nearer growth interface the position of highest temperature was, the larger the size of the MDs. Based on our experimental findings we suggested that the MDs' formation and the polytype switching from 6H‐ to 4H‐SiC were due to too large axial and/or radial temperature gradients.The results would be helpful to improve the quality of SiC single crystals grown by PVT technique. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energetic Salts of Low‐Symmetry Methylated 5‐Aminotetrazoles
Authors: Klapötke Thomas M. , Miró Sabaté Carles , Penger Alexander , Rusan Magdalena , Welch Jan M. 
Published: January 2009

AbstractIonic salts containing the novel 5‐amino‐2‐methyl‐ and 5‐amino‐1,3‐dimethyltetrazolium cations with energetic anions (perchlorate, nitrate, azide and dinitramide) have been synthesized in high yields and purities and fully characterized. A full structural description by spectroscopic methods (vibrational and 15N NMR spectroscopy) and X‐ray analysis is given. Unexpectedly, salts based on the asymmetric 5‐amino‐1,3‐dimethyltetrazolium cation have higher densities than analogue compounds containing the isomeric 5‐amino‐1,4‐dimethyltetrazolium cation, regardless of the lower symmetry of the former. This can be attributed to secondary interactions between the cation and anion and is reflected in the higher detonation parameters of the new compounds, which represent a new class of nitrogen‐rich, high‐performing materials with low sensitivity and good potential for energetic applications. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Elimination of an Alkyl Group from Imidazolium Salts: Imidazole‐Coordinated Dinuclear Monodentate NHC–Palladium Complexes Driven by Self‐Assembly and Their Application in the Heck Reaction
Authors: Liu Lian‐jun , Wang Feijun , Shi Min 
Published: January 2009

AbstractA new family of imidazole‐coordinated monodentate NHC–metal complexes 9 was obtained as well as cis‐chelatedbidentate NHC–metal complexes 10 from novel bis(imidazolium) salts 4 with a biphenyl backbone. The structures of complexes 9a and 10b were determined by X‐ray crystal‐structure diffraction, and their application in the Heck reaction showed good to excellent catalytic activities under very mild conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
1,8‐Bis(dialkylamino)‐4,5‐dinitronaphthalenes and 4,5‐Bis(dimethylamino)naphthalene‐1,8‐dicarbaldehyde as “Push–Pull” Proton Sponges: When and Why Formyl Groups Become Stronger π‐Electron Acceptors than Nitro Groups
Authors: Ozeryanskii Valery A. , Pozharskii Alexander F. , Artaryan Alexander K. , Vistorobskii Nikolai V. , Starikova Zoya A. 
Published: January 2009

AbstractSingle‐crystal X‐ray studies of four representatives of “push–pull” proton sponges, namely 1,8‐bis(dimethylamino)‐, 1,8‐bis(diethylamino)‐, 1,8‐bis(dipropylamino)‐4,5‐dinitronaphthalenes and 4,5‐bis(dimethylamino)naphthalene‐1,8‐dicarbaldehyde have been performed at low and ambient temperatures. The most interesting and unexpected result is that the formyl groups in the peri‐dialdehyde display stronger π‐acceptor effects than the nitro groups. This phenomenon is ascribed to smaller steric demands of the CHO groups, their lower electrostatic repulsion, and specific packing forces. The naphthalene cores of all but one of the molecules are markedly twisted (21–26°) while that of the diethylamino derivative is not (<5°), providing different and somewhat unpredictable ways of resonance stabilization and steric relaxation. The through‐conjugation in the above compounds is also discussed for gas and solution phases on the basis of theoretical calculations, UV/Vis and 1H NMR spectra.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Thermal Rearrangements of Perchlorohexatrienes–Structures and Experimental and Theoretical Evaluation of Pathways to Isomerization and Cyclization
Authors: Detert Heiner , Lenoir Dieter , Zipse Hendrik 
Published: January 2009

AbstractWe have prepared trans‐ (1) and cis‐octachloro‐1,3,5‐hexatriene (2) by known routes and studied their thermal behavior experimentally and theoretically by ab initio calculations. The three double bonds in 1 and 2 are completely decoupled due to steric hindrance by the eight Cls, as indicated by calculations as well as the single‐crystal X‐ray structure of 1. The cis isomer 2 can be isomerized to the trans isomer 1 by heating it to 220–250 °C either neat or dissolved in high‐boiling solvents, leading to a roughly 2:1 mixture of trans and cis isomers. Calculations at several different levels of theory predict 1 and 2 to be isoenergetic within 2 kJ mol–1. Unimolecular cis/trans isomerization is predicted to occur through an unusual vinylcyclobutene intermediate 7, whose formation faces a barrier of more than 150 kJ mol–1, but whose stability is comparable to that of 1 and 2. The isomerization rate is strongly enhanced by the addition of small amounts of Br2 or Cl2 or by 3 and can be explained by a radical‐induced isomerization mechanism. The heating of trienes 1 and 2 to 250 °C leads to cyclization, yielding 71 % of the cyclopentene isomer 3. Compound 3 can be dechlorinated by treatment with copper powder to give fulvene derivative 4. Using flash vacuum pyrolysis, the thermal conversion of trienes 1 and 2 to hexachlorobenzene (5) occurs at higher temperatures between 600–1000 °C, likely via perchlorinated 1,3‐cyclohexadiene (6) as an intermediate. The elimination of molecular Cl2 from 3 and 6 requires very high activitation energies in agreement with calculations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)