bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formal Total Synthesis of (+)‐Wortmannin Using Catalytic Asymmetric Intramolecular Aldol Condensation Reaction.
Authors: Shigehisa Hiroki , Mizutani Takashi , Tosaki Shin‐ya , Ohshima Takashi , Shibasaki Masakatsu 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Electrical and Photonic Functions Originating from Low‐Dimensional Structures in Wide‐Gap Semiconductors LnCuOCh (Ln: Lanthanide, Ch: Chalcogen): A Review
Authors: Hiramatsu Hidenori , Kamioka Hayato , Ueda Kazushige , Hirano Masahiro , Hosono Hideo 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Insertion Reactions of the Stable Silylene Si[N(CH2tBu)2C6H4‐1,2]
Authors: Antolini Floria , Cai Xiaoping , Gehrhus Barbara , Hitchcock Peter B. , Lappert Michael F. , Parrucci Massimo , Slootweg J. Chris 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Carbon Dioxide, Carbonyl Sulfide, Carbon Disulfide, Isocyanates, Isothiocyanates, Carbodiimides, and Their Selenium, Tellurium, and Phosphorus Analogues
Authors: Braverman S. , Cherkinsky M. , Birsa M. L. 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
The Use of Selective Methods of Heteronuclear NMR Spectroscopy in Studies of Multicomponent Systems
Authors: Chernysh Yu. E. , Volynkin V. A. , Panyushkin V. T. , Kondakov V. I. , Korobov M. S. , Borodkin G. S. 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Was hat Anlagensicherheit mit Terrorismus zu tun?
Authors: Jochum C. 
Published: August 2005

AbstractDer Schutz von Chemieanlagen gegen Eingriffe Unbefugter muss in Anbetracht der neuen Dimension terroristischer Bedrohung neu überdacht und ggf. verstärkt werden. In einem Leitfaden der Störfall‐Kommission wird ein systematisches Vorgehen zur Bewertung der Gefährdung von Chemieanlagen vorgeschlagen. Dabei werden wesentliche Elemente des Sicherheitsberichts nach StörfallV zugrunde gelegt. Auch bei den Sicherheitsmaßnahmen gibt es erhebliche Synergien mit den klassischen Methoden der Anlagensicherheit – wodurch dies auch zu einem Thema für die DECHEMA wird. Ergänzt werden diese Instrumente durch Maßnahmen des Werkschutzes sowie als Ultima Ratio durch Sicherheitsüberprüfung von Mitarbeitern. Kontrovers diskutiert wird, inwieweit sensible Informationen aus der Offenlegungspflicht der Sicherheitsberichte entlassen werden können.
Neue Materialien für die Heterogene Katalyse
Authors: Schüth F. 
Published: August 2005

AbstractDie Katalyse ist eine Schlüsseltechnologie für die chemische Industrie und verwandte Sektoren. Trotz jahrzehntelanger Forschung auf diesem Gebiet werden immer wieder neue Materialien entdeckt, die als Katalysatoren interessant sein können. Dieser Beitrag stellt einige der in den letzten Jahren entdeckten Systeme vor, wobei der Schwerpunkt auf hochporösen Materialien und solchen mit hoher spezifischer Oberfläche liegt. Es ist heute möglich, die Materialeigenschaften während der Synthese so weit zu kontrollieren, dass in vielen Fällen von einem Maßschneidern der Katalysatoren gesprochen werden kann. Fünf stoffliche Systeme werden näher diskutiert, nämlich neue zeolithische Strukturen, geordnete mesoporöse Materialien, poröse Koordinationsverbindungen, Kohle‐templatierte oberflächenreiche Oxide und so genannte MoVTe‐Katalysatoren zur Propanoxidation.
Mikroverfahrenstechnik: Neue Herausforderungen für die Prozessintensivierung
Authors: Matlosz M. 
Published: August 2005

AbstractAuf der Grundlage der Fortschritte auf dem Gebiet der mikrostrukturierten Reaktoren und Prozesskomponenten muss ein neuer Weg zu radikalen Innovationsinitiativen zugunsten einer leistungsfähigen Prozessintensivierung in der chemischen Industrie geöffnet werden. Um das enorme Potenzial dieser neuen Technologien auszuschöpfen, ist es jetzt dringend notwendig, Konzipierungsstrategien zu entwickeln, die nicht nur rein technische sondern auch klare wirtschaftliche Vorteile bieten. Um neue technologische Optionen in eine echte industrielle Realität zu überführen, müssen Methoden und theoretische Werkzeuge vorhanden sein, die in der Lage sind, technische Verbesserungen individueller Einheiten zur globalen Leistungssteigerung eines ganzen Produktionssystems zu nutzen.
A combined implicit–explicit algorithm in time for non‐linear finite element analysis
Authors: Curiel Sosa J. L. , de Souza Neto E. , Owen D. R. J. 
Published: August 2005

AbstractAn algorithm combining the numerical execution in time of implicit and explicit methods of solution is presented in this paper. The algorithm swaps between both methods as required for the analysis. The whole mesh is solved for an unique method at once, i.e. there are no partitions of the mesh for separate implicit or explicit treatment of the solution. The combination is in‐time, in such a manner that if the implicit method starts diverging the explicit one is initiated by appropriate conditions of transition. The formulation is presented first and its implementation is validated by the analysis of a key numerical example. Copyright © 2005 John Wiley & Sons, Ltd.
Ramsey unsaturated and saturated graphs
Authors: Balister P. , Lehel J. , Schelp R.H. 
Published: August 2005

AbstractA graph is Ramsey unsaturated if there exists a proper supergraph of the same order with the same Ramsey number, and Ramsey saturated otherwise. We present some conjectures and results concerning both Ramsey saturated and unsaturated graphs. In particular, we show that cycles Cn and paths Pn on n vertices are Ramsey unsaturated for all n ≥ 5. © 2005 Wiley Periodicals, Inc.
Identification of marker proteins for Bacillus anthracis using MALDI‐TOF MS and ion trap MS/MS after direct extraction or electrophoretic separation
Authors: Stump Michael J. , Black Gavin , Fox Alvin , Fox Karen F. , Turick Charles E. , Matthews Michael 
Published: August 2005

AbstractDirect extraction of bacterial vegetative cells or spores followed by matrix‐assisted laser desorption ionization/time of flight mass spectrometry (MALDI TOF MS) has become popular for bacterial identification, since it is simple to perform and mass spectra are readily interpreted. However, only high‐abundance proteins that are of low mass and ionize readily are observed. In the case of B. anthracis spores, small acid‐soluble spore proteins (SASPs) have been the most widely studied. Additional information can be obtained using tandem mass spectrometry (MS‐MS) to confirm the identity of proteins by sequencing. This is most readily accomplished using ion trap (IT) MS‐MS. However, enzymatic digestion of these proteins is needed to generate peptides that are within the mass range of the ion trap. The use of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE), or other forms of electrophoresis, allows one to focus on specific proteins of interest (e. g. the high mass exosporium glycoproteins BclA and BclB) that provide additional species‐ and strain‐specific discrimination.
Gamma irradiation of high density poly(ethylene)/ethylene‐vinyl acetate/clay nanocomposites: possible mechanism of the influence of clay on irradiated nanocomposites
Authors: Lu Hongdian , Hu Yuan , Kong Qinghong , Chen Zuyao , Fan Weicheng 
Published: August 2005

AbstractA further study on mechanical properties and morphology evolution of high density poly (ethylene)/ethylene‐vinyl acetate/and organically‐modified montmorillonite (HDPE/EVA/OMT) nanocomposites exposed to gamma‐rays (0–200 kGy) has been achieved. The results showed that nanocomposites have superior irradiation‐resistant properties to HDPE/EVA blend in mechanical properties. A transmission electron microscope study verified that a face‐face ordered nanostructure had been induced by gamma‐rays. The aim of this paper is to provide a possible mechanism on how the OMT influences the general properties of irradiated nanocomposites, based on the results of thermal, flammability and mechanical behavior. Three facts are postulated to be responsible for the mechanism. The first is the segregation of nano‐dispersed clay layers not only reduces polymer oxidation but prevents crosslinking reactions. The second is the nanostructure evolution induced by gamma‐rays, which may impart nanocomposites improved elasticity. The last is due to the Hofmann degradation, whose degraded products have opposite roles, accelerating polymer oxidation or promoting crosslinking reactions. These facts interact as well as compete with others. The properties of the nanocomposites strongly depended on the prevalent effects developing with increasing irradiation doses. Copyright © 2005 John Wiley & Sons, Ltd.
Optically high transparency and light color of organosoluble polyamides containing trifluoromethyl and kink diphenylmethylene linkage
Authors: Liaw Der‐Jang 
Published: August 2005

AbstractNew polyamides were prepared directly from a diamine, bis[4‐(2‐trifluoromethyl 4‐aminophenoxy)phenyl] diphenylmethane, containing an electron‐withdrawing trifluoromethyl group and a kink diphenylmethylene linkage with various aromatic dicarboxylic acids having inherent viscosities ranging from 0.66 to 0.83 dL g−1. All the polyamides showed outstanding solubility and could be easily dissolved in amide‐type polar aprotic solvents (e.g., N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, and N,N‐dimethylformamide) and even dissolved in less polar solvents (e.g., pyridine, cyclohexanone, and tetrahydrofuran). The dielectric constants of the polyamide films were 3.37–3.87 (100 KHz) and decreased with an increase in the frequency, which ranged from 1 Hz to 100 KHz. A low coefficient of thermal expansion for the polyamides was observed in the range of 54–78 ppm/°C (by thermomechanical analysis). These polyamides showed excellent thermal stability, and the 10% weight loss temperatures were in the range of 484–507 °C in an atmosphere of nitrogen. The polymers had an initial modulus of 1.8–2.2 GPa. The polyamides with kink and electron‐withdrawing trifluoromethyl units afforded light‐color polymer films with high transmittance in the visible region (400–700 nm), and their cutoff wavelength was lower than 362 nm. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4559–4569, 2005
Aromatic polyesters from naturally occurring monosaccharides: Poly(ethylene terephthalate) and poly(ethylene isophthalate) analogs derived from D‐mannitol and galactitol
Authors: Zamora Francisca , Hakkou Khalid , Alla Abdelilah , Rivas Manuel , Roffé Isaac , Mancera Manuel , Muñoz‐Guerra Sebastián , Galbis Juan A. 
Published: August 2005

AbstractThe synthesis and characterization of a new series of aromatic polyesters based on D‐mannitol and galactitol are described. These polyesters were obtained by polycondensation reaction of the terephthaloyl chloride or isophthaloyl chloride and 2,3,4,5‐tetra‐O‐methyl‐D‐mannitol or 2,3,4,5‐tetra‐O‐methyl‐galactitol in o‐dichlorobenzene. All the new polyesters were characterized by elemental analyses, GPC, IR, and NMR. They were soluble in chloroform, but insoluble in water and other polar oxygenated solvents. They showed a notable hygroscopicity, lower for those containing isophthalic units. DSC and X‐ray diffraction studies showed that D‐mannitol‐based polyesters were stiffer and less crystalline than those derived from galactitol, which presented a noticeably lower thermal stability. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4570–4577, 2005
Effective fixation of carbon dioxide into poly(glycidyl methacrylate) in the presence of pyrrolidone polymers
Authors: Yamamoto Shin‐Ichi , Kawabata Katsuyuki , Moriya Osamu , Endo Takeshi 
Published: August 2005

AbstractThe homopolymer (PGMA) of glycidyl methacrylate (GMA) and the copolymer of GMA with N‐vinyl‐2‐pyrrolidone were prepared under radical conditions and employed for the fixation of CO2 with LiBr as a catalyst, in which the oxirane groups were transformed into five‐membered cyclic carbonate groups. For the fixation of CO2 into the oxirane groups on PGMA, poly(N‐vinyl‐2‐pyrrolidone), in which the catalyst was impregnated before the reaction, was found to be an effective additive. This was exploited for the reaction using the copolymer containing both the oxirane and pyrrolidone moieties. The oxirane groups on the copolymer were also converted readily to the cyclic carbonates through the fixation of CO2. In such use of the pyrrolidone structures on the polymers, the fixation of CO2 could be carried out effectively in a diluted chlorobenzene solution and also under solvent‐free conditions. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4578–4585, 2005
Synthesis and characterization of poly(2‐ethylhexyl methacrylate) copolymers containing pendant, self‐complementary multiple‐hydrogen‐bonding sites
Authors: Elkins Casey L. , Park Taigyoo , McKee Matthew G. , Long Timothy E. 
Published: August 2005

AbstractThe synthesis and characterization of copolymers containing 2‐ethylhexyl methacrylate and a quadruple‐hydrogen‐bonding site, 2‐ureido‐4[1H]‐pyrimidone methacrylate (UPyMA), are described. An analogous dimeric hydrogen‐bond‐containing copolymer based on 2‐ethylhexyl methacrylate and methacrylic acid (PEHMA‐co‐MAA) was also synthesized for comparative purposes. The glass‐transition temperatures of the poly(2‐ethylhexyl methacrylate‐co‐2‐ureido‐4[1H]‐pyrimidone methacrylate) (PEHMA‐co‐UPyMA) series increased linearly with increasing UPyMA content. Creep compliance measurements as a function of temperature indicated a decrease in the creep compliance with increasing UPyMA content over the range of 1–10 mol % UPyMA. Melt rheological analysis also showed an increase and lengthening of the plateau modulus as a function of frequency with increasing UPyMA content, as well as increasing complex viscosity as a function of temperature. The analogous PEHMA‐co‐MAA copolymer, which contained 11 mol % methacrylic acid, showed, in the melt rheological analysis, behavior similar to that of the PEHMA‐co‐UPyMA copolymer containing only 1 mol % UPyMA units. The multiple‐hydrogen‐bond‐containing copolymers were successfully analyzed with time–temperature superposition for the construction of master curves. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4618–4631, 2005
Infrared‐to‐visible upconversion luminescence in neodymium‐doped bismuth–borate glass
Authors: Oprea Isabella‐Ioana , Hesse Hartmut , Betzler Klaus 
Published: August 2005

AbstractThe upconversion luminescence in Nd3+‐doped bismuth–borate glass, excited by 0.8 µm light, was studied in the visible spectral region. Four distinct emission bands were found. From their kinetics, two mechanisms can be shown to be responsible for all four lines: energy‐transfer upconversion, slightly dominating, and excited state absorption. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and Crystal Structure of a [Mo8O26]4–Cluster Derivative with 4‐MePyH+. First β‐Octamolybdate Derivative with π–π Stacking
Authors: Aguado R. , Pedrosa M. R. , Arnáiz F. J. 
Published: August 2005

AbstractDioxobis(pyridine‐2‐thiolate‐N, S)molybdenum(VI) (MoO2(Py‐S)2), reacts with of 4‐methylpyridine (4‐MePy) in acetonitrile, by slow diffusion, to afford the title compound. This has been characterized by elemental analysis, IR and1H NMR spectroscopy. The X‐ray single crystal structure of the complex is described. Structural studies reveal that the molecular structure consists of a β‐Mo8O26polyanion with eight MoO6distorted edge‐shared octahedra with short terminal Mo–O bonds (1.692–1.714 Å), bonds of intermediate length (1.887–1.999 Å) and long bonds (2.150–2.473 Å). Two different types of hydrogen bonds have been found: N–H···O (2.800–3.075 Å) and C–H···O (3.095–3.316 Å). The presence of π–π stacking interactions and strong hydrogen bonds are presumably responsible for the special disposition of the pyridinic rings around the polyanion cluster.
Fixation of Sulphur Dioxide by Manganese(II)‐Schiff Base Complexes: Thermal Stability of these Adducts and the Possible Conversion of the Coordinated SO2 to Sulphate
Authors: Maneiro Marcelino , Fernández Beatriz , Gómez‐Fórneas Esther , Rodríguez M Jesús , Pedrido Rosa , Romero M. José , Bermejo Manuel R. 
Published: August 2005

AbstractA series of manganese(II) complexes of general formula MnLn(H2O)m (where H2Ln are substituted N,N′‐bis(salicylidene)‐1,2‐diimino‐2,2‐dimethylethane) have been prepared by electrochemical synthesis and characterized by analytical and spectroscopic techniques, magnetism and by studying their redox reversibility character by cyclic and normal pulse voltammetry. The reactivity of these complexes with sulphur dioxide has been investigated in the solid state and in toluene slurries at room temperature. The studies of the reversibility of the reaction (desorption studies) by thermogravimetrical analysis (TGD) have shown a different behaviour among the SO2‐adducts (from irreversible to totally reversible fixing), pointing to different SO2 binding modes. Thus, adducts 10, 12 and 14, kept the SO2 after TGD, signifying S–bridged SO2 binding mode, while TGD for 8, 9 and 13 revealed the lability of their SO2, attributable to ligand bound SO2 coordination. The manganese(II) precursor 4 is that one which has the ability of reversily fixing a major quantity of SO2 and undergoes the sulphato reaction to form 11 also.
Hydrothermal Synthesis, Crystal Structures and Effect of Non Bonding Interactions in Crystal Packing of Two Mixed‐Ligand Metal Complexes with Glycolato and 2,2′‐Dipiridylamine and with Benzilato and Imidazole
Authors: Carballo Rosa , Covelo Berta , Vázquez‐López Ezequiel M. , García‐Martínez Emilia , Castiñeiras Alfonso , Janiak Christoph 
Published: August 2005

AbstractTwo new mixed‐ligand complexes [Fe(HG)2(dipyam)] (1) (HG = glycolato and dipyam = 2,2′‐dipyridylamine) and [Cu(HB)2(im)2]·2H2O (2) (HB = benzilato and im = imidazole) have been hydrothermally synthesized and structurally characterised by X‐ray diffraction. In both cases the metallic centre is in an octahedral environment, strongly distorted in 2 (4+2 coordination). The α‐hydroxycarboxylato ligands (glycolato or benzilato) present different coordinative behaviour, bidentade chelate through the hydroxyl oxygen and one carboxy oxygen in 1 and through the two oxygen atoms of the carboxylate group in 2. The complexes are extended into 2D frameworks through hydrogen bonding and π···π or C‐H···π interactions. The complexes were also characterized by elemental analysis, FT‐IR and UV‐vis spectroscopy and room temperature magnetic measurements.
Protein Unfolding: 1H‐NMR Studies of Paramagnetic Ferricytochrome c‐550 from Horse Heart
Authors: Jiménez Hermas R. , Ruiz de Sola Esther , Moratal José M. , Arbona Maria 
Published: August 2005

AbstractElectronic transfer protein cytochrome c‐550 from horse heart is studied in the unfolded state by means of paramagnetic 1H NMR. The protein contains 104 aminoacid residues and a heme group with low spin FeIII ion in the oxidized form of protein. The global secondary structure is of the α‐helix type as occurs in the case of very other cytochromes c investigated such as cyt c‐550 from Thiobacillus versutus or cyt c‐551 from Pseudomonas aeruginosa. We have studied the coordination characteristic and electronic properties of heme iron horse heart ferricytochrome c‐550 at increasing denaturing conditions (up to 3.1 M GuHCl and 288‐323 K). The 1H T1 values of the signals were measured and some resonance assignments made based on EXSY experiments. The electronic structure of the iron(III) is discussed on the basis of the temperature dependence of the isotropic shifts and relaxation times. These results show that it is produced a change of spin, from low‐spin iron(III) (2T2, S=1/2) in the folded state to high‐spin iron(III) (6A1, S=5/2) in the unfolded state. It seems to be possible that in the opened structure the ferricyt c‐550 loses one axial ligand (His/‐) appearing the spin transition.
Hydrothermal Synthesis, Crystal Structure, Spectroscopic and Magnetic Properties of (C3H12N2)0.75[FeII1.5FeIII1.5(AsO4)F6]
Authors: Bazan B. , Mesa J. L. , Pizarro J. L. , Peña A. , Arriortua M. I. , Rojo T. 
Published: August 2005

AbstractA new iron(II)‐iron(III) mixed valence fluoro‐arsenate compound templated by propanediammonium cations has been synthesized by using mild hydrothermal conditions. The crystal structure has been solved from single‐crystal x‐ray diffraction data. This phase crystallizes in the Imam space group with the unit‐cell parameters a = 7.566(2), b = 11.034(3) and c = 13.233(5) Å. The compound exhibits a three‐dimensional framework constructed from two kinds of chains which delimit cavities in which the pro pane diammonium cations are located. Mössbauer and diffuse reflectance spectroscopies confirm the presence of Fe(II, III) mixed valence cations and the existence of slightly distorted octahedral environments for the metallic centres. Magnetic measurements indicate the existence a three‐dimensional antiferromagnetic ordering at 6 K. However, at low temperatures, a small hysteresis loop is observed. The values of the remanent magnetization and coercitive field are 400 emu/mol and 1180 G, respectively. These results are in good agreement with the existence of a ferromagnetic component due to a spin descompensation by the mixed valence nature of this phase.
Metal Complexes of New Mixed Oxaaza‐Macrocyclic Ligands. X‐Ray Crystal Structure of L1, L2, [SrL2(H2O)2](ClO4)2 and [BaL2(NCS)2(CH3CN)]·CH3CN
Authors: López‐Deber Montserrat , Bastida Rufina , Fernández‐Fernández Maria del Carmen , Macías Alejandro , Rodríguez Adolfo , Valencia Laura 
Published: August 2005

AbstractA new mixed oxaaza‐macrocyclic ligand, L1, has been obtained by direct synthesis between 1,4‐bis‐(2′‐formylphenyl)‐1,4‐dioxabutane and the diamine 2,2′‐ethylenedioxydiethylamine. The dialkylated ligand L2, bearing two nitrobenzyl pendant groups, has been prepared and transitional, post‐transitional and Ca2+, Sr2+, and Ba2+ metal complexes have been synthesized in order to elucidate the coordination preferences.The crystal structures of the ligands L1 and L2 and the complexes [SrL2(H2O)2](ClO4)2 and [BaL2(NCS)2(CH3CN)]·CH3CN have been determined by single crystal X‐ray diffraction. The structures reveal the presence of mononuclear endomacrocyclic complexes where the pendant arms radiate away from the ligand.
Heteronuclear Nickel‐Iron Complexes and the Crystal Structure of [Fe2(CO)6(μ3‐S)2{Ni(dppe)}]
Authors: Lozano A. Abel , Santana M. Dolores , García Gabriel , Barclay J. Elaine , Davies Siân C. , Evans David J. 
Published: August 2005

AbstractA series of heteronuclear nickel‐iron complexes [Fe2(CO)6(μ‐SH)(μ3‐S){NiCl(PPh3)2}] (1), [Fe2(CO)6(μ‐SH)(μ3‐S){NiCl(dppe)}] (2), [Fe2(CO)6(μ3‐S)2{Ni(PPh3)2}] (3), [Fe2(CO)6(μ3‐S)2{Ni(dppe)}] (4) and [Fe2(CO)6(μ‐SPh)(μ3‐S){NiCl(dppe)}] (5) have been prepared. The structure of 4 has been determined by X‐ray crystallography. The central metal‐sulfur core of 4 has a trigonal bipyramidal shape with a NiFe2 base plane with two axial sulfur atoms. Each iron atom is 5‐coordinate forming a distorted square pyramid; the nickel is square planar coordinated by two sulfur atoms and two phosphorus atoms.