Published by De Gruyter

Volume 33 Issue 5

Issue of Zeitschrift für Naturforschung A

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Open Access June 2, 2014

Zur Bestimmung der Beweglichkeit und Gleichgewichtskonstanten komplexierter Ionen mittels Gegenstromionenwanderung / Determination of the Mobilities and Stability Constants of Complex Ions by Means of Counter current Ion Migration

F. Herrmann, B. A. Bilal

Page range: 507-513

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Abstract

In a countercurrent ion migration process the ion of an element (e.g. a metal cation) can form various unstable complexes with the anion of the countercurrent electrolyte. The ion migrates then with an average mobility, which is a function of the mobilities and equilibrium constants of the equilibrated species. In order to hold a constant ionic strength and to establish various metal/ligand-ratios, a background ion must be mixed to the metal ion. In usual "statical" stationary distributions, in which neither the metal ion nor the background ion is transported, the ratio of the two can only be hold constant if their mobilities are very similar. This difficulty can be overcome if the background ion is transported with constant rate through a statical stationary distribution of the metal ion, and vice versa. The solution of the transport equation for such "dynamical" stationary distributions shows that the average mobility of the metal ion can be calculated if its concentrations in locally independent parts of the stationary distribution and in the overflow are measured. The mobilities and the equilibrium constants of the various complex species are then determined by means of known mathematical methods

Open Access June 2, 2014

¹³C- and Proton-ENDOR Studies of ¹³C-labelled Organic Radicals

H.-J. Fey, W. Lubitz, H. Zimmermann, M. Plato, K. Möbius, R. Biehl

Page range: 514-522

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Abstract

As part of a systematic non-proton ENDOR-in-solution study results are reported for 13 C in several isotopically enriched model compounds. Methods for synthesizing these labelled compounds are also presented. The optimum 13 C ENDOR temperatures are found to be considerably higher than for protons on account of the larger hyperfine anisotropy. Cross relaxation effects are used to determine rotational correlation times. The isotropic 13 C hyperfine couplings are in satisfactory agreement with INDO results

Open Access June 2, 2014

Surface Analysis of InSb by X-Ray Photoelectron Spectroscopy (XPS)

R. G. Copperthwaite, O. A. Kunze, J. Lloyd, J. A. Neely, W. Tuma

Page range: 523-527

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Abstract

Surface compositions of single-crystal specimens of InSb have been investigated by XPS. A correlation between the degree of surface oxidation and the type of chemical etchant used has been found. This interpretation is based on chemical-shift data and argon-ion bombardment experiments, together with XPS results obtained on polycrystalline indium and antimony

Open Access June 2, 2014

Über die Gleichgewichtsverteilung von Ionen an Phasengrenzen / About the Distribution of Ions near a Phase-Boundary

Gerhard West

Page range: 528-535

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Abstract

For ideal-diluted electrolytes the concentration and potential profiles are calculated and the consequences of the deviation from the limiting law are discussed

Open Access June 2, 2014

Arachidate Layers on Ag and Au Substrates Detected by the A T R Method

G. Wähling

Page range: 536-539

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Abstract

Monolayers of cadmium arachidate (thickness 26.8 A) are deposited on Ag and Au substrates. They can be detected by the resonance excitation of surface plasmons (ATR method). The number of monolayers is correlated with the displacement of the reflection minimum. The observed values of the position of the minima as well as the shape of the reflection curve are in agreement with the calculated ones, using a refractive index of cadmium arachidate of 1.52 in agreement with other measurements

Open Access June 2, 2014

Collisional Activation Spectra of Quaternary Phosphonium and Tertiary Sulfonium Cations Produced by Field Desorption

R. Weber, F. Borchers, K. Levsen, F. W. Röllgen

Page range: 540-548

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Abstract

The collisional activation spectra of a variety of tetraalkyl phosphonium and trialkyl sulfonium ions generated by field desorption are reported. The fragmentation behaviour of the onium ions is compared with that of ammonium ions, reported earlier [4] and the corresponding open shell amine, phosphine and sulfide molecular ions. Cleavage of the heteroatom -carbon bond, with or without hydrogen rearrangement (i.e. alkyl and alkane loss) leads to prominent fragment ions in all onium ions. Pronounced heterolytic cleavage of this bond was only observed in sulfonium ions. No direct ɑ-cleavage of the cation is observed, however, ɑ-cleavage can occur in a second step after elimination of a substituent. This process leads to the base peak with ammonium ions, occurs less frequently in sulfonium ions and cannot be observed unequivocally in phosphonium ions. In addition, the collisional activatiou spectra of phenylalkyl phosphonium ions and chlorine containing quaternary phosphonium ions are discussed. It is demonstrated that collisional activation in conjunction with field desorption is a useful technique for the structure elucidation of onium cations

Open Access June 2, 2014

The Microwave Spectrum of Oxazole

II. Dipole Moment and Quadrupole Coupling Constants

Anil Kumar, John Sheridan, Otto L. Stiefvater

Page range: 549-558

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Abstract

The dipole moments and the quadrupole coupling constants of the normal and the three mono-deuterated species of oxazole have been measured. The dipole moment of 1.50 ± 0.03 D is found to deviate by 10.8° from the external bisector of the CNC angle towards the C(2) carbon atom. The principal values of the quadrupole coupling tensor are determined as X zz = -4.04 ± 0.02 MHz and X xx - 1-66 ± 0.02 MHz along the axes in the molecular plane, so that the gradient perpendicular to this plane is X yy = 2.38 MHz. The direction of the largest gradient deviates by 5.7° from the external bisector of the CNC angle towards the carbon atom C(4). An attempt is made to correlate these results and the geometry of oxazole with the electron distribution in this molecule

Open Access June 2, 2014

Riemannian Curvature and the Petrov Classification

G. S. Hall

Page range: 559-562

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Abstract

A connection is shown between the Riemannian Curvatures of the wave surfaces of a null vector I at a point p in space-time and the Petrov type of the space-time at p. Some other results on Riemannian Curvature are discussed

Open Access June 2, 2014

A Method for the Study of Correlated Events in Time-of-Flight Mass-Spectrometry and its Application to Fission-Fragment Induced Desorption

Norbert Fürstenau

Page range: 563-570

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Abstract

For experiments on fission-fragment induced desorption the detection of significant correlations between desorbed ions has been reported [1]. In this paper the method for the detection and quantitative description of these correlations will be described. The statistics of the desorption-process leads to equations for mass-line intensities of ion spectra. Using a time-to-amplitude-converter for flight-time measurements these intensities depend on interdependences of different ions desorbed by the same fission-fragment. The equations allow the computation of correlationcoefficients whose interdependence with desorption probabilities of the respective ions can be shown in Venn-diagrams. Results are given and an interpretation is suggested for fission-fragment desorbed thiamine molecular and fragment ions

Open Access June 2, 2014

Mikrowellenspektren schwingungsangeregter Zustände und allgemeines Valenzkraftfeld von ¹²C³²SF³⁵Cl / Microwave Spectra of Some Vibrational Excited States of ¹²C³²SF³⁵Cl

R. Hamm

Page range: 571-580

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Abstract

The microwave spectra of some vibrational excited states of CSFC1 were measured with a conventional stark modulation spectrometer. As the spectra of the upper two stretching vibrations could not be found for lack of intensity, the equilibrium structure which had been estimated using Kuchitsu's procedure could not yet be determined. Nevertheless a general internal force field of CSFC1 was obtained, using the inertial defects of the measured excited states in the fit program NCA in addition to vibration frequencies and centrifugal distortion constants. Moreover, from the determined anharmonic part of the rotation vibration interaction constants, linear relations between some cubic force constants were established

Open Access June 2, 2014

Microwave Spectrum of Cyclopentene-3,5-dione

P. J. Mjöberg, S. O. Ljunggren, J. E. Bäckvall

Page range: 581-587

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Abstract

The microwave spectra of cyclopentene-3,5-dione in the ground state and the first four excited states of the ring bending vibration have been studied in the frequency region 26.5 to 40.0 GHz and the corresponding rotational constants have been determined. The ground state spectrum of one isotopically substituted species, 4-deuteriocyclopentene-3,5-dione, has also been assigned. The following values of the ground state rotational constants (MHz) were obtained from the spectra: From intensity and inertial-defect considerations the ring configuration was shown to be planar in the ground state. In addition, the nearly straight-line behaviour of the rotational constants as functions of the ring-puckering vibrational quantum number indicates that the ring-puckering vibration is nearly harmonic with a fundamental frequency of approximately 90 cm -1 . The electric dipole moment for the unsubstituted species in the vibrational ground state was found to be 1.680 ± 0.009 Debye units

Open Access June 2, 2014

Turbulent Spatio-Temporal Dynamics in Reacting-Diffusing Systems: Results for a Soluble Model

P. Ortoleva, M. DelleDonne

Page range: 588-596

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Abstract

A class of soluble three "species" reaction-diffusion type systems is presented Exact solutions are obtained which show turbulent spatio-temporal evolution All homogeneous evolution tends asymptotically toward an attractor which is shown to be a two layered two dimensional manifold in the three dimensional species space. Sustained aperiodic spatio-temporal solutions are also found. By considering particular model systems we show that turbulent solutions may exit as finite amplitude instabilities or as bifurcations which are aperiodic arbitrarily close to the bifurcation point and hence do not arise as a transition starting out essentially periodically. A perturbation scheme is used to show that d parameter families of spatio-temporal evolution are admitted by more general systems with attracting d dimensional manifolds in the homogeneous chemical kinetics

Open Access June 2, 2014

The Electric Conductivity of the Molten Systems BiBr₃-HgBr₂ and BiBr₃-CdBr₂

Slavko V. Mentus, Milenko V. Šušić

Page range: 597-600

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Abstract

The electric conductivity of the molten binary mixtures BiBr 3 -HgBr 2 and BiBr 3 -CdBr 2 was measured for different molar compositions of the mixtures over the temperature ranges 500-770 K and 720-870 K , respectively. The curves o f the specific conductivity as a function of composition show in the BiBr 3 -HgBr 2 system negative and positive deviations from additivity in the HgBr 2 - rich and BiBr 3 - rich composition regions, respectively. In the BiBr 3 -CdBr 2 system the isotherms o f specific conductivity deviate positively from additivity over the entire composition range

Open Access June 2, 2014

Untersuchung der elektrischen Leitfähigkeit im nematischen und smektischen Phasenbereich von 4-Alkyloxy-4'-cyanobiphenylen / Study of the Electrical Conductivity in the Nematic and Smectic Phases of 4-Alkyloxy-4''-cyanobiphenyls

F. Schneider

Page range: 601-609

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Abstract

The electrical conductivity of tetrabutylammonium picrate is measured in the liquid crystal phases of two 4-alkyloxy-4'-cyanobiphenyls as a function of the temperature and of the electrolyte concentration. The conductivity is corrected for the electrode polarization and the dielectric relaxation which are determined from the frequency dependence of the conductivity. The equivalent conductivity values in the nematic phase of a mixture of 4-pentyloxy-4'- cyanobiphenyl and 4-heptyloxy-4'-cyanobiphenyl are extrapolated to infinite dilution. The electrical conductivity in 4-octyloxy-4'-cyanobiphenyl is measured in the nematic and in the smectic phase. It changes continuously with the temperature in the region of the phase transition. The anisotropy ratio for both liquid crystals under investigation yields a strong dependence upon the concentration of the electrolyte. This behaviour is compared with results obtained for other liquid crystals

Open Access June 2, 2014

The Structure of the Other Rotamer of Formic Acid, cis-HCOOH^1,2

E. Bjarnov, W. H. Hocking

Page range: 610-618

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Abstract

The very weak microwave spectra of six isotopically substituted species of formic acid in the cis rotamer form (i.e. with the two hydrogen atoms cis to each other) have been studied. From the data on HC 18 OOH, HCO 18 OH, H 13 COOH, HCOOD, DCOOH and DCOOD, together with the previously published data for HCOOH, the complete substitution structure of the eis rotamer of formic acid has been derived. The structure is: r s (C-H) = 1.105(4) A, r s (C=O) = 1.195(3) A, r s (C-O) = 1.352(3) Å, r s (O-H) = 0.956(5) Å, ∢(OCO) = 122.1(4)°, ∢(HC-O) = 114.6(6)° and ∢(COH) = 109.7(4)°

About this journal

Objective
A Journal of Physical Sciences: Zeitschrift für Naturforschung A (ZNA) is an international scientific journal which publishes original research papers from all areas of experimental and theoretical physics. Authors are encouraged to pay particular attention to a clear exposition of their respective subject, addressing a wide readership. In accordance with the name of our journal, which means “Journal for Natural Sciences”, manuscripts submitted to ZNA should have a tangible connection to actual physical phenomena. In particular, we welcome experiment-oriented contributions.

Manuscripts considered for publication in A Journal of Physical Sciences: Zeitschrift für Naturforschung A undergo high-level refereeing. Mere formal correctness of a paper is not sufficient for its acceptance. Moreover, articles reporting a merely marginal extension of already existing knowledge are considered unsatisfactory. Instead, the key quality a publication in A Journal of Physical Sciences: Zeitschrift für Naturforschung A should possess is that it makes a genuine contribution to the advancement of its topic.

Topics

Atomic, Molecular & Optical Physics
Chemical Physics
Dynamical Systems & Nonlinear Phenomena
Fundamental Concepts of Physical Sciences
Gravitation & Cosmology
Hydrodynamics & Plasma Physics
Nuclear Physics & Particle Physics
Quantum Field Theory
Solid State Physics & Materials Science
Thermodynamics & Statistical Physics
Article formats
Original research articles, research notes, letters and review articles from all areas of theoretical and experimental physics

Information on submission process

Volume 33 Issue 5

Issue of Zeitschrift für Naturforschung A

Zur Bestimmung der Beweglichkeit und Gleichgewichtskonstanten komplexierter Ionen mittels Gegenstromionenwanderung / Determination of the Mobilities and Stability Constants of Complex Ions by Means of Counter current Ion Migration

Abstract

13C- and Proton-ENDOR Studies of 13C-labelled Organic Radicals

Abstract

Surface Analysis of InSb by X-Ray Photoelectron Spectroscopy (XPS)

Abstract

Über die Gleichgewichtsverteilung von Ionen an Phasengrenzen / About the Distribution of Ions near a Phase-Boundary

Abstract

Arachidate Layers on Ag and Au Substrates Detected by the A T R Method

Abstract

Collisional Activation Spectra of Quaternary Phosphonium and Tertiary Sulfonium Cations Produced by Field Desorption

Abstract

The Microwave Spectrum of Oxazole

II. Dipole Moment and Quadrupole Coupling Constants

Abstract

Riemannian Curvature and the Petrov Classification

Abstract

A Method for the Study of Correlated Events in Time-of-Flight Mass-Spectrometry and its Application to Fission-Fragment Induced Desorption

Abstract

Mikrowellenspektren schwingungsangeregter Zustände und allgemeines Valenzkraftfeld von 12C32SF35Cl / Microwave Spectra of Some Vibrational Excited States of 12C32SF35Cl

Abstract

Microwave Spectrum of Cyclopentene-3,5-dione

Abstract

Turbulent Spatio-Temporal Dynamics in Reacting-Diffusing Systems: Results for a Soluble Model

Abstract

The Electric Conductivity of the Molten Systems BiBr3-HgBr2 and BiBr3-CdBr2

Abstract

Untersuchung der elektrischen Leitfähigkeit im nematischen und smektischen Phasenbereich von 4-Alkyloxy-4'-cyanobiphenylen / Study of the Electrical Conductivity in the Nematic and Smectic Phases of 4-Alkyloxy-4''-cyanobiphenyls

Abstract

The Structure of the Other Rotamer of Formic Acid, cis-HCOOH1,2

Abstract

¹³C- and Proton-ENDOR Studies of ¹³C-labelled Organic Radicals

Mikrowellenspektren schwingungsangeregter Zustände und allgemeines Valenzkraftfeld von ¹²C³²SF³⁵Cl / Microwave Spectra of Some Vibrational Excited States of ¹²C³²SF³⁵Cl

The Electric Conductivity of the Molten Systems BiBr₃-HgBr₂ and BiBr₃-CdBr₂

The Structure of the Other Rotamer of Formic Acid, cis-HCOOH^1,2