Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Photodissociation of rovibrationally excited C2H2: Observation of two pathways (1997)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 107 (1997), S. 385-391 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: C2H2 is prepared in the 2030000 (five quanta of C–H stretch) vibrational state and photodissociated by 243.135 nm photons that also probe the H photofragments via (2+1) resonance-enhanced multiphoton ionization (REMPI) in a time-of-flight mass spectrometer. The production of H atoms is greatly enhanced upon rovibrational excitation. The REMPI action spectrum shows the characteristic features of a Σu+–Σg+ band and mimics the absorption spectrum, except that the R(13) line intensity is an order of magnitude higher than that expected for a Boltzmann distribution. The maximum translational energy of the H atoms obtained from dissociation of the regularly distributed rotational states is 0.67±0.10, whereas for R(13) it is 1.34±0.10 eV. The observed intensities and linewidths indicate the existence of two photodissociation pathways following the preparation of C2H2, where the C2H fragment is produced in two different states. In the R(13) pathway an additional bent state is prepared, or an accidental coincidence resonance is involved. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.474399
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The substitution chemistry of RuCp* (temeda)Cl (1997)
    Springer
    Monatshefte für Chemie 128 (1997), S. 1189-1199 
    Details
    ISSN: 1434-4475
    Keywords: Ruthenium half-sandwich complexes ; Tetramethylethylenediamine ; Ruthenacycles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Chloridabspaltung von RuCp*(tmeda)Cl (1,tmeda=Me2NCH2CH2NMe2) mittels NaBPh4 in CH2Cl2 führt zur Bildung des Halbsandwich-Komplexes RuCp*(η6-C6H5BPh3) (2), während in Gegenwart von CH3CN oder CO die beiden kationischen Verbindungen [RuCp*(tmeda)(CH3CN)]+ (3) und [RuCp*(tmeda)(CO)]+ (5) entstehen. In CH3CN als Lösungsmittel wird sogartmeda unter Bildung von [RuCp*(CH3CN)3]+ (4) verdrängt. Komplex1 reagiert sehr leicht mit terminalen Alkinen HC≡CR, wobei die Produkte stark von der Natur des SubstituentenR (Ph, SiMe3,n-Bu, COOEt) abhängen. Im Fall vonR=Ph entsteht der Ruthenacyclopentatrien-Komplex RuCp*(σσ′-C4Ph2H2)Cl (6), mitR=SiMe3 der Cyclobutadien-Komplex Ru(Cp*)(η4-C4H2(1,2-SiMe3)2)Cl (7), und im Fall vonR=n-Bu und COOEt bilden sich die binuklearen Komplexe (Cp*)RuCl2(η2:η4-μ2-C4H2(1,3-R)2)Ru(Cp*) (8,9). Überdies reagiert1 mit Maleinsäurediethylester in Gegenwart von LiCl zum neuen anionischen Komplex Li[Ru(Cp*) (η2-C2H2(COOEt)2)Cl2] (10). Von2,3,4,7 und10 wurden die Kristallstrukturen bestimmt.
    Notes: Summary Halide abstraction from RuCp*(tmeda)Cl (1,tmeda=Me2NCH2CH2NMe2) with NaBPh4 in CH2Cl2 leads to the formation of the sandwich complex RuCp*(η6-C6H5BPh3) (2). In the presence of CH3CN (1 equiv.) and CO, however, the cationic complexes [RuCp*(tmeda)(CH3CN)]+ (3) and [RuCp*(temeda)(CO)]+ (5) are obtained. In CH3CN,tmeda is also replaced giving [RuCp*(CH3CN)3]+ (4). Complex1 reacts readily with terminal acetylenes HC≡CR, the products depending on the nature ofR (Ph, SiMe3,n-Bu, COOEt). Thus, withR=Ph the ruthenacyclopentatriene complex RuCp*(σ,σ′-C4Ph2H2)Cl (6), withR=SiMe3 the cyclobutadiene complex Ru(Cp*)(σ4-C4H2(1,2-SiMe3)2)Cl (7), and withR=n-Bu and COOEt the binuclear complexes (Cp*)RuCl2(η2:η4-μ2-C4H2(1,3-R)2)Ru(Cp*) (8,9) are obtained. Furthermore, with diethyl maleate in the presence of 1 equiv. of LiCl,1 transforms into the new anionic complex Li[Ru(Cp*) (η2-C2H2(COOEt)2)Cl2] (10). X-ray structures of2,3,4,7, and10 are included.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00807250
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and X-ray structures of some mono- and binuclear ruthenium complexes with bisphosphine ligands (1997)
    Springer
    Monatshefte für Chemie 128 (1997), S. 533-540 
    Details
    ISSN: 1434-4475
    Keywords: Ruthenium ; Binuclear complexes ; X-Ray analysis ; Oxidation ; Bisphosphines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Komplexe {RuCp*(μ-Cl)}2(μ-dppm) (1) und {RuCp*(μ-Cl2(μ-dppe) (3) wurden durch Umsetzung von [RuCp*(μ3-Cl)]4 mitdppm bzw.dppe dargestellt.1 wird durch AgCF3SO3 zum zweikernigen Komplex [{RuCp*(μ-Cl)}2(μ-dppm)](SO3CF3)2 (2) oxidiert, welcher eine Ru-Ru-Metallbindung aufweist. Unter den gleiche Reaktionsbedingungen zersetzt sich3 zu undefinierten Produkten. Analog zu1 reagiert RuCp* (dmpe)Cl mit AgCF3SO3 zum Ru(III)-Komplex [Ru(Cp*)(dmpe)Cl](SO3CF3) (4) wobei es zu keiner Chloridabspaltung kommt. Von2,3, und4 wurden die Kristallstrukturen bestimmt.
    Notes: Summary The dinuclear complexes {RuCp*(μ-Cl)}2(μ-dppm) (1) and {RuCp*(μ-Cl)}2 (μ-dppe) (3) are obtained by reacting [RuCp*(μ3-Cl)]4 withdppm, anddppe, respectively.1 is readily oxidized with AgCF3SO3, instead of chloride abstraction, to afford the dinuclear complex [{RuCp*(μ-Cl)}2(μ-dppm)](SO3CF3)2 (2) with two metal centers connected by a single Ru-Ru bond. Under the same conditions,3 decomposes to several intractable materials. Similarly to1, RuCp* (dmpe)Cl reacts with AgCF3SO3 to afford the Ru(III) complex [RuCp*(dmpe)Cl](SO3CF3) (4) without no halide abstraction. The crystal structures of2,3, and4 are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00807583
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Kongenitale myotone Dystrophie (1997)
    Springer
    Monatsschrift Kinderheilkunde 145 (1997), S. 588-592 
    Details
    ISSN: 1433-0474
    Keywords: Schlüsselwörter Kongenitale myotone Dystrophie ; Curshmann-Steinert-Batten-Syndrom ; CTG-Trinukleotid-Sequenzwiederholung ; Dystrophia myotonica ; Facies myopathica ; Key words Congenital myotonia dystrophy ; Curshmann-Steinert-Batten-Syndrom ; CTG-Trinukleotid sequence repetition ; Distrophy myotonica ; Facies myopathica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The subject of this report is a newborn female, suffering from hypotonia and breathing difficulties, delivered in the 37 week with the help of forceps. Because of the nature of her symptons and those of the mother, which included Facies myopathica and Myotonia, the possibility of the expansion of a CTG-Trinukleotidsequence in the area of Chromosom 19 was explored. For this purpose a technique, developed in 1992, for the identification of molecular genetic characteristics was used. Instead of the 5 to 27 copies of the CTG sequence normally found in the population, the sick child had 1000 and the mother more than 700. EMG, in which a classical relases of myotones (Fall-Fight-Bomberscream) were found, confirmed the neurological diagnosis. Discussion: In the course of time the newborn child showed the classical problems of hyptotonia, such as respiratory difficulties, eating disorders leading to a loss of weight, meteroism, and after another stay in hospital, symptoms of Ileus.
    Notes: Zusammenfassung Es wird über ein in der 37. SSW durch Forzeps geborenes Mädchen berichtet, das durch Hypotonie und Ateminsuffizienz auffiel. Diese Symptome, ebenso wie die Facies myopathica und die Myotonie der Hand der Mutter bei der Begrüßung, gaben den Hinweis zur Durchführung der seit 1992 möglichen molekulargenetischen Bestimmung der Expansion einer CTG-Trinukleotidsequenz im Bereich des Chromosoms 19. Statt der in der Normalbevölkerung 5–27 Kopien dieser CTG-Sequenz-Wiederholung fanden sich bei dem erkrankten Kind über 1000 und bei der Mutter über 700. Darüber hinaus konnte durch eine neurologische Untersuchung der Mutter die bisher unbekannte Diagnose bestätigt werden, wobei im EMG eine klassische myotone Entladung (Sturz-Kampf-Bomber-Geräusch) gefunden wurde. Diskussion: Beim Neugeborenen traten im weiteren Verlauf die klassischen Folgeprobleme der Hypotonie wie Respiratorbedürftigkeit und Ernährungsprobleme mit relativer Gewichtsabnahme, Meteorismus und bei einer erneuten stationären Aufnahme Ileussymptomatik auf.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001120050156
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Structural and biochemical properties of glycosylated and deglycosylated glucose oxidase from Penicillium amagasakiense (1997)
    Springer
    Applied microbiology and biotechnology 47 (1997), S. 502-507 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Glucose oxidase from Penicillium amagasakiense was purified to homogeneity by ion-exchange chromatography and deglycosylated with endoglycosidase H. On the basis of gas chromatography and sodium dodecyl sulphate/polyacrylamide gel electrophoretic (SDS-PAGE) analyses, the protein-bound high-mannose-type carbohydrate moiety corresponded to 13% of the molecular mass of glycosylated glucose oxidase. A total of six N-glycosylation sites per dimer were determined from the N-acetylglucosamine content. The enzymatically deglycosylated enzyme contained less than 5% of the original carbohydrate moiety. A molecular mass of 130 kDa (gel filtration) and 133 kDa (native PAGE) was determined for the dimer and 67 kDa (SDS-PAGE) for the monomer of the deglycosylated enzyme. The N-terminal sequence, which has not been published for glucose oxidase from P. amagasakiense to date and which showed less than 50% homology to the N terminus of glucose oxidase from Aspergillus niger, and the amino acid composition were not altered by the deglycosylation. Deglycosylation also did not affect the kinetics of glucose oxidation or the pH and temperature optima. It also did not increase the susceptibility of the enzyme to proteolytic degradation. However, deglycosylated glucose oxidase exhibited decreased pH and thermal stability. The thermal stability of both enzymes was shown to be dependent on the buffer concentration and was enhanced by certain additives, particularly 1 M (NH4)2SO4, which stabilised glucose oxidase 100- to 300-fold at 50 °C and pH 7–8, and 2 M KF, which stabilised the enzyme up to 36-fold at 60 °C and pH 6. In sodium acetate buffer, changes in pH (4–6) affected the affinity for glucose but had no effect on the V max of the reaction. In contrast, in TRIS buffer, pH 8, a 10-fold decrease in V max and a 2-fold decrease in K m were observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050963
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Electron Beam Probing—A Solution for MCM Test and Failure Analysis (1997)
    Springer
    Journal of electronic testing 10 (1997), S. 55-63 
    Details
    ISSN: 1573-0727
    Keywords: electron-beam testing ; short ; open ; MCM ; printed circuit board
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Electron beam probing is applied for test and analysis of miniaturisedMCM structures. Wiring structures are tested for shorts and opens while fullyassembled MCMs are analysed in order to identify process or design problems[1, 2]. An electron beam short/open tester for laminated substrates has beendeveloped and installed. It allows the test of substrates up to a size of300 × 300 mm2 with a spot size ofbelow 30 μm without mechanical movement. The system is automated for routineapplication in the fabrication line. Electron beam probe stations are common tools for design verification and debugging ofintegrated circuits. This type of system was adapted to MCMrequirements. The travel range was extended to 80 × 100 mm2 to allow for waveform measurements anddiagnostics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008270430950
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...