bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solution Structure of the Leader Sequence of the Patellamide Precursor Peptide, PatE1–34
Authors: Houssen Wael E. , Wright Stephen H. , Kalverda Arnout P. , Thompson Gary S. , Kelly Sharon M. , Jaspars Marcel 
Published: August 2010

AbstractThe solution structure of the leader sequence of the patellamide precursor peptide was analysed by using CD and determined with NOE‐restrained molecular dynamics calculations. This leader sequence is highly conserved in the precursor peptides of some other cyanobactins harbouring heterocycles, and is assumed to play a role in targeting the precursor peptide to the post‐translational machinery. The sequence was observed to form an α‐helix spanning residues 13–28 with a hydrophobic surface on one side of the helix. This hydrophobic surface is proposed to be the site of the initial binding with modifying enzymes.
Membrane‐Surface Anchoring of Charged Diacylglycerol‐Lactones Correlates with Biological Activities
Authors: Raifman Or , Kolusheva Sofiya , El Kazzouli Said , Sigano Dina M. , Kedei Noemi , Lewin Nancy E. , Lopez‐Nicolas Ruben , Ortiz‐Espin Ana , Gomez‐Fernandez Juan C. , Blumberg Peter M. , Marquez Victor E. , Corbalan‐Garcia Senena , Jelinek Raz 
Published: August 2010

AbstractSynthetic diacylglycerol‐lactones (DAG‐lactones) are effective modulators of critical cellular signaling pathways, downstream of the lipophilic second messenger diacylglycerol, that activate a host of protein kinase C (PKC) isozymes and other nonkinase proteins that share similar C1 membrane‐targeting domains with PKC. A fundamental determinant of the biological activity of these amphiphilic molecules is the nature of their interactions with cellular membranes. This study examines the biological properties of charged DAG‐lactones exhibiting different alkyl groups attached to the heterocyclic nitrogen of an α‐pyridylalkylidene chain, and particularly the relationship between membrane interactions of the substituted DAG‐lactones and their respective biological activities. Our results suggest that bilayer interface localization of the N‐alkyl chain in the R2 position of the DAG‐lactones inhibits translocation of PKC isoenzymes onto the cellular membrane. However, the orientation of a branched alkyl chain at the bilayer surface facilitates PKC binding and translocation. This investigation emphasizes that bilayer localization of the aromatic side residues of positively charged DAG‐lactone derivatives play a central role in determining biological activity, and that this factor contributes to the diversity of biological actions of these synthetic biomimetic ligands.
Highlights of Transition Metal‐Catalyzed Asymmetric Hydrogenation of Imines
Authors: Fleury‐Brégeot Nicolas , de la Fuente Verónica , Castillón Sergio , Claver Carmen 
Published: August 2010

AbstractThis Review deals with the asymmetric hydrogenation and asymmetric transfer hydrogenation of imines and some nitrogen‐containing heteroaromatic compounds to afford amines. Hydrogenation and transfer hydrogenation are covered in separate sections. Particular attention is devoted to the substrates, since this reaction is highly substrate dependent. In this way the general structural trends in imine hydrogenation are presented, highlighting the more challenging substrates. Since hydrogenation of acyclic and cyclic (including heteroaromatic) imines have some different features they are also presented separately. The catalytic systems are classified according to the metal, and focus on the most successful catalytic systems and metal–ligand combinations. The catalytic cycles for these hydrogenation processes are also proposed.
Secondary Phosphane Oxides as Preligands in Rhodium‐Catalyzed Hydroformylation
Authors: Christiansen Andrea , Li Chuanzhao , Garland Marc , Selent Detlef , Ludwig Ralf , Franke Robert , Börner Armin 
Published: August 2010

AbstractFour aryl‐substituted secondary phosphane oxides (SPOs) were tested as preligands in the rhodium catalyzed hydroformylation of cyclohexene and 1‐octene. Three of them form active hydroformylation catalysts through their phosphinous acid tautomers. n‐Regioselectivities of up to 56 % were achieved in the reaction with the linear olefin. The catalytic system with the electron‐poor SPO showed exceptional behavior. In situ high‐pressure IR spectroscopic investigations accompanied by DFT calculations provide an explanation of the observed inhibition of the catalytic reaction. Furthermore, proof is given that noncoordinated SPOs readily react with product aldehydes at room temperature to form α‐hydroxyphosphinic acids. In contrast Rh‐catalyzed hydrophosphination did not take place.
Acceleration of the Rate of the Heck Reaction through UV‐ and Visible‐Light‐Induced Palladium(II) Reduction
Authors: Fredricks Margaret Anne , Drees Markus , Köhler Klaus 
Published: August 2010

AbstractIrradiation with light (UV and visible) increases the rate of the Heck reaction using homogeneous (palladium(II) acetate) and heterogeneous (Pd/Al2O3 and Pd/TiO2) catalysts. The rate of the coupling of bromobenzene, chlorobenzene, and 4‐chloroacetophenone with styrene was increased under light irradiation at temperatures between 90 and 160 °C. Detailed investigations showed that light irradiation accelerates the reduction of the PdII precursor, as confirmed by 31P NMR spectroscopy, in which the in situ reduction of [Pd(OAc)2(PPh3)2] to [Pd(PPh3)n] (n=2–4) in the presence of PPh3 took only minutes under visible light irradiation and several hours in the dark. The role of light is, however, complex since it also influences other PdII reduction steps in conjunction with catalyst deactivation (Pd black formation). 31P NMR spectroscopy showed the same active species, anionic palladium halide complexes, in both irradiated and unirradiated reactions. UV/Vis absorption spectroscopy of Pd(OAc)2 and DFT calculations, theoretical UV/Vis spectra, and orbital calculations of [PdI4]2−, [PdBr4]2−, and [PdCl4]2−, showed that ligand‐to‐metal charge transfer (LMCT) is responsible for the accelerated reduction of PdII to Pd0 under light irradiation.
A Mathematical Model for Predicting Release Rate from Multiple Emulsions and Micro/Nanospheres
Authors: Dluska E. , Markowska‐Radomska A. 
Published: August 2010

AbstractThis paper presents mass transfer models of the release process from hierarchical dispersed systems such as multiple emulsions and micro/nanospheres. The models were validated by experimental data of an active component released from multiple emulsions and microspheres obtained via multiple emulsion thermal cross‐linking. The simulations of release profiles confirmed the importance of the internal structure of multiple emulsions/microspheres, as well as the intensity of external mixing in the modeling of the controlled release process. The models presented allowed the mass released to be determined within satisfactory agreement with experimental data after optimization of parameters that describe internal emulsion/microsphere structure. The model proposed for describing the release process from microspheres can simulate release profiles that exhibit phasic behavior (primary/lag and continuous release). The model simulations were extended to nanoscale particles with satisfactory results.
Expanded Pyridiniums: Bis‐cyclization of Branched Pyridiniums into Their Fused Polycyclic and Positively Charged Derivatives—Assessing the Impact of Pericondensation on Structural, Electrochemical, Electronic, and Photophysical Features
Authors: Fortage Jérôme , Tuyèras Fabien , Ochsenbein Philippe , Puntoriero Fausto , Nastasi Francesco , Campagna Sebastiano , Griveau Sophie , Bedioui Fethi , Ciofini Ilaria , Lainé Philippe P. 
Published: August 2010

AbstractThis study evaluates the impact of the extension of the π‐conjugated system of pyridiniums on their various properties. The molecular scaffold of aryl‐substituted expanded pyridiniums (referred to as branched species) can be photochemically bis‐cyclized into the corresponding fused polycyclic derivatives (referred to as pericondensed species). The representative 1,2,4,6‐tetraphenylpyridinium (1H) and 1,2,3,5,6‐pentaphenyl‐4‐(p‐tolyl)pyridinium (2Me) tetra‐ and hexa‐branched pyridiniums are herein compared with their corresponding pericondensed derivatives, the fully fused 9‐phenylbenzo[1,2]quinolizino[3,4,5,6‐def]phenanthridinium (1Hf) and the hitherto unknown hemifused 9‐methyl‐1,2,3‐triphenylbenzo[h]phenanthro[9,10,1‐def]isoquinolinium (2Mef). Combined solid‐state X‐ray crystallography and solution NMR experiments showed that stacking interactions are barely efficient when the pericondensed pyridiniums are not appropriately substituted. The electrochemical study revealed that the first reduction process of all the expanded pyridiniums occurs at around −1 V vs. SCE, which indicates that the lowest unoccupied molecular orbital (LUMO) remains essentially localized on the pyridinium core regardless of pericondensation. In contrast, the electronic and photophysical properties are significantly affected on going from branched to pericondensed pyridiniums. Typically, the number of absorption bands increases with extended activity towards the visible region (down to ca. 450 nm in MeCN), whereas emission quantum yields are increased by three orders of magnitude (at ca. 0.25 on average). A relationship is established between the observed differential impact of the pericondensation and the importance of the localized LUMO on the properties considered: predominant for the first reduction process compared with secondary for the optical and photophysical properties.
Photolysis and Thermolysis of Platinum(IV) 2,2′‐Bipyridine Complexes Lead to Identical Platinum(II)–DNA Adducts
Authors: Loup Christophe , Tesouro Vallina Ana , Coppel Yannick , Létinois Ulla , Nakabayashi Yasuo , Meunier Bernard , Lippert Bernhard , Pratviel Geneviève 
Published: August 2010

AbstractTwo PtIV and two PtII complexes containing a 2,2′‐bipyridine ligand were treated with a short DNA oligonucleotide under light irradiation at 37 °C or in the dark at 37 and 50 °C. Photolysis and thermolysis of the PtIV complexes led to spontaneous reduction of the PtIV to the corresponding PtII complexes and to binding of PtII 2,2′‐bipyridine complexes to N7 of guanine. When the reduction product was [Pt(bpy)Cl2], formation of bis‐oligonucleotide adducts was observed, whereas [Pt(bpy)(MeNH2)Cl]+ gave monoadducts, with chloride ligands substituted in both cases. Neither in the dark nor under light irradiation was the reductive elimination process of these PtIV complexes accompanied by oxidative DNA damage. This work raises the question of the stability of photoactivatable PtIV complexes toward moderate heating conditions.
Trifluoromethyl‐Substituted Conjugated Oligoelectrolytes
Authors: Ren Yan , Bazan Guillermo C. 
Published: August 2010

AbstractConjugated oligoelectrolytes (COEs) are being introduced into a variety of optical and electronic technologies, yet the dependence of their properties as a function of molecular structure remains poorly understood. In response, we designed, synthesized, and examined a new tetracationic COE, namely, 1,4‐bis{9′,9′‐bis[6′′‐(N,N,N‐trimethylammonium)hexyl]‐2′‐fluorenyl}‐2,5‐bis(trifluoromethyl)benzene tetrabromide (FPF‐F6), which contains bulky electron‐withdrawing trifluoromethyl groups, and compared its properties with the unsubstituted counterpart 1,4‐bis{9′,9′‐bis[6′′‐(N,N,N‐trimethylammonium)hexyl]‐2′‐fluorenyl}benzene tetrabromide (FPF). The ground‐state geometry of FPF‐F6 is primarily twisted with little electronic communication between the aromatic units, as confirmed by single‐crystal X‐ray diffraction studies of the neutral precursor. However, absorption and photoluminescence spectroscopies reveal that the excited state of FPF‐F6 displays strong intramolecular charge‐transfer characteristics. Solution AFM in aqueous media shows that introduction of trifluoromethyl groups changes the size and aspect ratio of supramolecular aggregates that are brought together as a result of hydrophobic interactions. Furthermore, addition of ssDNA to FPF‐F6 leads to interoligoelectrolyte complexes wherein the backbone is more planar; the environment the chromophore experiences under these conditions is also considerably less polar. These findings provide considerable insight into the complex photophysics of electronically conjugated materials in aqueous media.
An Atomic‐Level Strategy for Unraveling Gold Nanocatalysis from the Perspective of Aun(SR)m Nanoclusters
Authors: Zhu Yan , Qian Huifeng , Jin Rongchao 
Published: August 2010

AbstractAn atomic‐level strategy is devised to gain insight into the origin of nanogold catalysis by using atomically monodisperse Aun(SR)m nanoclusters as well‐defined catalysts for styrene oxidation. The Aun(SR)m nanoclusters are emerging as a new class of gold nanocatalyst to overcome the polydispersity of conventional nanoparticle catalysts. The unique atom‐packing structure and electronic properties of Aun(SR)m nanoclusters (<2 nm) are rationalized to be responsible for their extraordinary catalytic activity observed in styrene oxidation. An interesting finding is that quantum size effects of Aun(SR)m nanoclusters, rather than the higher specific surface area, play a major role in gold‐catalyzed selective oxidation of styrene. For example, Au25(SR)18 nanoclusters (≈1 nm) are found to be particularly efficient in activating O2, which is a key step in styrene oxidation, and hence, the ultrasmall Au25 catalyst exhibits higher activity than do larger sizes. This atomic‐level strategy has allowed us to obtain an important insight into some fundamental aspects of nanogold catalysis in styrene oxidation. The ultrasmall yet robust Aun(SR)m nanoclusters are particularly promising for studying the mechanistic aspects of nanogold catalysis and for future design of better catalysts with high activity and selectivity for certain chemical processes.
[Pd(Cl)2{P(NC5H10)(C6H11)2}2]—A Highly Effective and Extremely Versatile Palladium‐Based Negishi Catalyst that Efficiently and Reliably Operates at Low Catalyst Loadings
Authors: Bolliger Jeanne L. , Frech Christian M. 
Published: August 2010

Abstract[Pd(Cl)2{P(NC5H10)(C6H11)2}2] (1) has been prepared in quantitative yield by reacting commercially available [Pd(cod)(Cl)2] (cod=cyclooctadiene) with readily prepared 1‐(dicyclohexylphosphanyl)piperidine in toluene under N2 within a few minutes at room temperature. Complex 1 has proved to be an excellent Negishi catalyst, capable of quantitatively coupling a wide variety of electronically activated, non‐activated, deactivated, sterically hindered, heterocyclic, and functionalized aryl bromides with various (also heterocyclic) arylzinc reagents, typically within a few minutes at 100 °C in the presence of just 0.01 mol % of catalyst. Aryl bromides containing nitro, nitrile, ether, ester, hydroxy, carbonyl, and carboxyl groups, as well as acetals, lactones, amides, anilines, alkenes, carboxylic acids, acetic acids, and pyridines and pyrimidines, have been successfully used as coupling partners. Furthermore, electronic and steric variations are tolerated in both reaction partners. Experimental observations strongly indicate that a molecular mechanism is operative.
3,4‐Dithiaphosphole and 3,3′,4,4′‐Tetrathia‐1,1′‐Biphosphole π‐Conjugated Systems: S Makes the Impact
Authors: Fadhel Omrane , Benkö Zoltán , Gras Michael , Deborde Valérie , Joly Damien , Lescop Christophe , Nyulászi László , Hissler Muriel , Réau Régis 
Published: August 2010

AbstractConjugated systems based on phospholes and 1,1′‐biphospholes bearing 3,4‐ethylenedithia bridges have been prepared using the Fagan–Nugent route. The mechanism of this organometallic route leading to intermediate zirconacyclopentadienes has been investigated by using theoretical calculations. This study revealed that the oxidative coupling leading to zirconacyclopentadienes is favored over oxidative addition within the SC≡C bond both thermodynamically and kinetically. The impact of the presence of the S atoms on the optical and electrochemical behavior of the phospholes and 1,1′‐biphospholes has been systematically evaluated both experimentally and theoretically. A comparison with their “all‐carbon” analogues is provided. Of particular interest, this comparative study revealed that the introduction of S atoms has an impact on the electronic properties of phosphole‐based conjugated systems. A decrease of the HOMO–LUMO separation and a stabilization of the LUMO level were observed. These general trends are also observed with 1,1′‐biphospholes exhibiting σ–π conjugation. The P atom of the 3,4‐ethylenedithiaphospholes can be selectively oxidized by S8 or O2. These P modifications result in a lowering of the HOMO–LUMO separation as well as an increase of the reduction and oxidation potentials. The S atoms of the 3,4‐ethylenedithia bridge of the 2,5‐phosphole have been oxidized using m‐chloroperoxybenzoic acid. The resulting 3,4‐ethylenesulfoxide oxophosphole was characterized by an X‐ray diffraction study. Experimental and theoretical studies show that this novel chemical manipulation results in an increase of the HOMO–LUMO separation and an important decrease of the LUMO level. The electropolymerization of 2‐thienyl‐capped 3,4‐ethylenedithiathioxophosphole and 1,1′‐biphosphole is reported. The impact of the S substituents on the polymer properties is discussed.
ChemInform Abstract: Neutron Diffraction Studies of Quadrupled Perovskites Sm2Ba2Cu2Ti1. 5Sn0.5O11, Sm2Ba2Cu2Ti1.55Sn0.2Sc0.25O11, and Gd2Ba2Cu2Ti2O11 and Calcium Doping of Gd2Ba2Cu2Ti2O11.
Authors: GORMEZANO A. , WELLER M. T. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Plasma‐Enhanced Chemical Vapor Deposited Phosphorus Sulfide Films. Characterization by Raman and Solid‐State NMR Spectroscopies and Comparison to Melt‐Quenched Glassy Materials.
Authors: SHIBAO R. K. , XIA Y. , SRDANOV V. I. , ECKERT H. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Effects of Ga Substitution in Y2Fe17 Compounds on the Magnetocrystalline Anisotropy.
Authors: SHEN B. , CHENG Z. , GONG H. , LIANG B. , YAN Q. , WANG F. , ZHANG J. , ZHANG S. , GUO H. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Structures and Magnetic Properties of the Lanthanoid Nickel Antimonides LnNiSb (Ln: La‐Nd, Sm, Gd‐Tm, Lu).
Authors: HARTJES K. , JEITSCHKO W. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Formation, Crystal Chemistry and Magnetism of Compounds RE2TGe6, RE: Rare Earth, T: Pd, Pt, Cu, Ag and Au.
Authors: SOLOGUB O. , HIEBL K. , ROGL P. , BODAK O. I. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Magnetic Hardening of Sm2Fe17‐xGaxC2.5 Compounds.
Authors: SHEN B. , KONG L. , GONG H. , CHENG Z. , LIANG B. , WANG F. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Investigation of the Alkali‐Metal Vanadium Oxide Xerogel Bronzes: AxV2O5×nH2O (A: K and Cs).
Authors: LIU Y.‐J. , COWEN J. A. , KAPLAN T. A. , DEGROOT D. C. , SCHINDLER J. , KANNEWURF C. R. , KANATZIDIS M. G. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Anodic Film Formation on a Sputter‐Deposited Al‐30 at.% Mo Alloy.
Authors: HABAZAKI H. , SKELDON P. , SHIMIZU K. , THOMPSON G. E. , WOOD G. C. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A Comparison Between the Corrosion Behavior of Sintered and Unsintered Porous Titanium.
Authors: SEAH K. H. W. , THAMPURAN R. , CHEN X. , TEOH S. H. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Photoassisted Chemisorption of NO on ZnO.
Authors: KASE K. , YAMAGUCHI M. , SUZUKI T. , KANEKO K. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of New Cesium‐Oxygen Graphite Intercalation Compounds.
Authors: MORDKOVICH V. Z. , BAXENDALE M. , OHKI Y. , YOSHIMURA S. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: PPh+ 4H2P‐ 7 ‐ The First Stable Hydrogen Polyphosphide Salt.
Authors: KORBER N. , VON SCHNERING H. G. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: P3N3F5NPF2NPF2NPF2‐ 5: A Cyclophosphazene with a Phosphazene Side‐ Chain Dianion by F‐‐Induced Ring‐Opening of P3N3F6.
Authors: LORK E. , WATSON P. G. , MEWS R. 
Published: August 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.