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  • Inorganic Chemistry  (14)
  • 06  (2)
  • Rare earth elements  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 22 (1980), S. 185-187 
    ISSN: 1432-0630
    Keywords: 06 ; 07 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract New methods for thermal-equilibrium investigations of atomic vacancies or of dislocation movements in metals require measurements of minute resistance fluctuations. The accuracy of such measurements is limited by thermal noise from the resistor. The present paper proposes a method for analysing resistance fluctuations independent of voltage noise.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0630
    Keywords: 06 ; 07 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A novel method is presented for measuring the spectral density of resistance fluctuations without the explicit determination of the voltage background noise (Johnson noise, pre-amplifier noise). The output of a standard ac bridge excited by a single-frequency alternating current is demodulated by two phase-sensitive detectors which operate in quadrature. When the phase difference between excitation and detection is properly set, the real part of the cross-spectral density of the two demodulators shows only the spectral density of the resistance fluctuations and not the disturbing background noise. The feasibility of our new method is demonstrated by measurements of 1/f noise of a thin-film A1 sample.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 75 (1989), S. 173-194 
    ISSN: 1432-2234
    Keywords: Pseudopotentials ; Rare earth elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Nonrelativistic and quasirelativistic energy-adjusted pseudopotentials and optimized (7s6p5d)/[5s4p3d]-GTO valence basis sets for use in molecular calculations for fixed f-subconfigurations of the rare earth elements, La through Lu, have been generated. Atomic excitation and ionization energies from numerical HF, as well as SCF pseudopotential calculations using the derived basis sets, differ by less than 0.1 eV from numerical HF all-electron results. Corresponding values obtained from CI(SD), CEPA-1, as well as density functional calculations using the quasirelativistic pseudopotentials, are in reasonable agreement with experimental data.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 75 (1989), S. 369-387 
    ISSN: 1432-2234
    Keywords: Pseudopotentials ; Rare earth elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Nonrelativistic and quasirelativistic energy-adjusted pseudopotentials for fixed 4f subconfigurations of the rare earth elements La through Lu together with corresponding optimized valence basis sets have been used in SCF and CI(SD) calculations to determine the spectroscopic constants for the energetically low lying superconfigurations of the lanthanide monohydrides, monoxides and monofluorides. The experimentally observed trends in dissociation energies, bond lengths and vibrational frequencies for the ground states of the calculated superconfigurations of the monoxides and monofluorides are well reproduced. The results for the monohydrides are mainly predictions.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 406 (1974), S. 307-311 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Vibrational Spectrum of Tetra-thiomethyl-phosphoniuin-hexachloroantimonatePreparation, properties and vibrational spectrum of Tetra-thiomethyl-phosphonium-hexachloroantimonate are reported. The kind of bonding in the ion is brief discussed.
    Notes: Es wird über die Darstellung, Eigenschaften und Schwingungsspektren des Tetra-thiomethyl-phosphonium-hexachloroantimonats berichtet. Die Bindungsverhältnisse werden kurz diskutiert.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 442 (1978), S. 221-224 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: About the Fluorescence Thermochromism of Acetonitrile Copper Iodide with Dibenzo-18-Crown-6Copper iodide reacts in actonitrile solution with dibenzo-18-crown-6 to form a compound,(CuJ)4(CH3CN)4(db-18-c-6), which fluoresces yellow at 298K, but pink at 77 K. It decomposes at 55.3°C. (5 Torr) by lost of acetonitrile and a heterogeneous mixture of copper iodide and polyether results. In absence of dibenzo-18-crown-6, copper iodide forms with acetonitrile a heterogeneous mixture of copper iodide and polyether results. In absence of dibenzo-18-crown-6, copper iodide forms with acetonitrile a solvate CuJ. CH3CN. It also shows fluorescence thermochromism (yellow at 298 K, but green at 77 k) but decomposes at 0°C and 760 Torr.The luminescences pectra of the macrocyclic polyether complex at 298 K is redshifted. This probably results from intersection between the crown and the acetonitrile copper iodide.
    Notes: Kupferjodid bildet in Acetonitril mit Dibenzo-18-Krone-6 eine Verbindung der Zusammensetzung (CuJ)4(CH3CN)4(db-18-c-6), die bei Raumtemperatur gelb, bei 77K rosa fluoresziert. Sie zersetzt sich bei 55,3°C (5 Torr) unter Verlust von Acetonitril zu einem heterogenen Gemenge aus Kronenäther Kupferjodid.In Abwesenheit von Kronenäther bildet Kupferjodid in Acetonitril ein Solvat CuJ · CH3CN. Es ist ebenfalls fluoreszenzthermochrom (gelb bei 298 K, grün bei 77 K) und zersetzt sich allerdings schon bei 0°C( 760 Torr). Das Lumineszenzspektrum des makrocyclischen Polyätherkomplexes ist bei 298 K rotverschoben, was wahrscheinlich auf die Wechselwirkung des Kronenäthers mit dem Acetonitrilo-Kupferjodid zurückzuführen ist.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 389 (1972), S. 269-279 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The vibration spectra (IR and RAMAN) are reported for OPF2(CH3), OPF(CH3)2, SPF2(CH3), SPF(CH3)2 and SPF2(C2H5) and assigned to the normal vibrations. For these compounds all valence force constants are calculated by a simplified valence force field. Substitution of fluorine atoms by the methyl group causes a diminuation of all force constants. There is a clear difference between Δf P—CH3 (- 18%) and Δf X =P and Δf P—F (-30%). The P—CH3 bond is incapable to form dπ—pπ-bonds. Therefore the diminuation of f P—CH3 is caused only by the inductive effect.
    Notes: Von OPF2(CH3), OPF(CH3)2, SPF2(CH3), SPF(CH3)2 und SPF2(C2H5) werden die Schwingungsspektren (meistens IR und RAMAN) mitgeteilt und den Grundschwingungen zugeordnet. Gemeinsam mit den Endgliedern XPF3 und XP(CH3)3 (X = O, S) werden die Valenzkraftkonstanten nach einem Näherungsverfahren berechnet. Sämtliche Kraftkonstanten nehmen beim Ersatz von Fluor durch die Methylgruppe stark ab. Für f P—CH3 (-18%) ergibt sich gegenüber f P = X und f P—F (-30%) ein deutlicher Unterschied, bedingt durch die Unfähigkeit der CH3-Gruppe zur Ausbildung von dπ—pπ-Bindungen. Die Abnahme für f P—CH3 wird auf den induktiven Effekt allein zurückgeführt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The vibrational spectra (IR and RAMAN) from XP(N(CH3)2)2Cl and XP(N(CH3)2)Cl2 (X = O, S) are reported. The spectra are discussed and assigned to the normal vibrations in connection with the spectra of XP(N(CH3)2)3 and XPCl3. The valence force constants are calculated by a simplified valence force field. f P-NR2 and f P-Cl decrease slightly on substitution of the NR2 group by chlorine; f P-X, on the contrary, increases very distinctly. This is caused by the change from an element of the second period to an element of the third one.
    Notes: Es werden die Schwingungsspektren (IR und RAMAN) von XP(N(CH3)2)2Cl und XP(N(CH3)2)Cl2 mitgeteilt und in Zusammenhang mit den Spektren der Randglieder dieser Reihe XP(N(CH3)2)3 und XPCl3 (X = O, S) diskutiert und zugeordnet. Auf dieser Grundlage wurden nach einem Näherungsverfahren die Valenzkraftkonstanten ermittelt. Während f P-NR2 und f P-Cl beim Ersatz der NR2-Gruppen durch Chlor leicht abnehmen. zeigen beide f P-X eine starke Zunahme. Da beide Bindungspartner (NR2 und Cl) ungefähr gleiche Elektronegativität besitzen, so muß die starke Zunahme von f P-X auf die Zugehörigkeit der beiden Bindungspartner zu verschiedenen Perioden des Systems zurückgeführt werden.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vibrational Spectra and Force Constants of the Series OPF3—OP(OCH3)3 and SPF3—SP(OCH3)3The vibrational spectra (IR and RAMAN) for OPF2(OCH3), OPF(OCH3)2, SPF2(OCH3) and SPF(OCH3)2 are reported and assigned to the normal vibrations. The valence force constants are calculated by a simplified valence force field. The changes of the bonds are discussed.
    Notes: Es werden die Schwingungsspektren (IR und RAMAN) von OPF2(OCH3), OPF(OCH3)2, SPF2(OCH3) und SPF(OCH3)2 mitgeteilt und die Zuordnung zu den Grundschwingungen vorgenommen. Nach einem Näherungsverfahren werden die Valenzkraftkonstanten berechnet und die Bindungsverhältnisse diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 480 (1981), S. 199-204 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Effect of Substituents and Anions on the Fluorescence Properties of Mixed-Ligand (Amine-triphenylphosphane) Copper(I) HalidesMixed-ligand complexes analyzing CuHal · PΦ3 · Py—R where Hal = Cl-, Br-, I- and where R are various substituents at the pyridine (Py) exhibit an intense solid state fluorescence depending on substituent and anion when excited with uv radiation (365 nm). It will be shown that there is a relation between fluorescence and mesomeric and inductive properties of substituents and anions.
    Notes: Gemischtligandige Komplexe der Zusammensetzung CuHal · PΦ3 · Py—R mit Hal = Cl-, Br-, I- und R = verschiedenen Substituenten am Pyridin (Py) weisen bei UV-Bestrahlung (365 nm) im festen Zustand eine intensive Fluoreszenz auf. Es soll gezeigt werden, daß ein Zusammenhang der Fluoreszenz mit den mesomeren und induktiven Eigenschaften von Substituenten und Anionen besteht.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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