bluuebunny/crossref_metadata_2025 huggingface dataset:
∆SCF and Transition Operator (TO) Calculations in the Theoretical Determination of Vertical Ionization Energies in Transition Metal Compounds
Authors: Böhm Michael C.
Published: February 2015

The interrelation between theoretically determined vertical ionization potentials in transition metal compounds based on the ∆SCF approximation (Iv,j
∆SCF) and based on the “transition operator (TO)” method (Iv,j
TO) has been investigated. Numerical results in the outer valence region have been obtained by means of semiempirical INDO calculations. The difference between the calculated ionization energies (Iv,j
∆SCF and Iv,j
TO) is enlarged with increasing atomic numbers of the transition metal center due to noncompensating terms in third order of perturbation. The neces­sary conditions for the imbalance of both theoretical procedures are large two-electron interaction integrals and highly populated transition metal hole-states. Both requirements are enhanced by going from the left side of the 3d series to the extreme right. For d4-d6 complexes a simplified expression for Iv,j
∆SCF has been derived containing only one third order element.
Zur Beschreibung weitreichender Kopplungen mittels der Pars-Orbital-Methode / Long-range Couplings, Methyl-substituted Coumarines and Carbostyriles, Pars-Orbital and Pertur-bational Calculations
Authors: Fabian Walter , Sterk Heinz
Published: February 2015

An attempt has been made to correlate long range couplings in a series of methyl-substituted coumarines and carbostyriles with the character orders of the corresponding propen- and methyl-butadienfragments. In the case that these character orders exceed a threshold value of about 0.700, relatively large long-range couplings are to be expected. In addition calculations of these couplings by the finite perturbation approach have been performed.
Gas-Phase Tautomerism in the Triazoles and Tetrazoles: A Study by Photoelectron Spectroscopy and ab Initio Molecular Orbital Calculations
Authors: Palmer Michael H. , Simpson Isobel , Wheeler J. Ross
Published: February 2015

The photoelectron spectra of the tautomeric 1,2,3,- and 1,2,4-triazole and 1,2,3,4-tetrazole systems have been compared with the corresponding N-methyl derivatives. The dominant tautomers in the gas phase have been identified as 2 H-1,2,3-triazole, 1 H-1,2,4-triazole and 2H-tetrazole.

Full optimisation of the equilibrium geometry by ab initio molecular orbital methods leads to the same conclusions, for relative stability of the tautomers in each of the triazoles, but the calculations wrongly predict the tetrazole tautomerism.
Notizen: Catalytic Silver Reduction in Sulphide Containing Silver Chloride Melts
Authors: Lieser Thomas , Weil Konrad G.
Published: February 2015

In silver chloride melts, containing small mole fractions of silver sulphide (~ 10-2 - 10-3), silver ion reduction takes place when solid silver is present. The rate of reaction is constant with time and proportional to the area of the metal. In the temperature range 780 K< T < 890 an ap­parent energy of activation of 1.3 · 102 kJ mol-1 is ob­tained.
Application of Multichannel Scattering Theory to Pionic Reactions Within the Lee Model
Authors: Sawicki M. , Schütte D.
Published: February 2015

The multichannel scattering theory is applied to the (2,2) sector of the (non-static) Lee model. Rigorous expressions for the transition amplitudes for two-fragments channels are derived. These expressions contain all effects of off-shell renormalization in a complete and consistent way. With suitable identification of the elementary fields of the model the reactions considered correspond to a simplified description of elastic proton-proton and pion-deuteron scattering and to pion absorption on the deuteron. We obtain a two-body equation for the description of the elastic proton-proton scattering and an extension of the two-potential formula for the pion-deuteron scattering, which can be cast into the form of the multiple-scattering series.
Internal Rotation Spectrum in the Ground State of cis Propionyl Fluoride
Authors: Scappini F. , Dreizler H.
Published: February 2015

The microwave ground state spectrum of cis propionyl fluoride has been investigated expanding, with respect to a previous study, the range of the quantum numbers of the transitions, J up to 40 and K up to 18. At low K the spectrum resembles that of an asymmetric rigid rotor, except in a number of cases where the lines are split into A, E doublets. At intermediate and high K the mixing of the if-doublet rigid rotor wave functions makes forbidden transitions appear. The results of the analysis of the methyl top internal rotation ground state splittings are: V3 = 2350 ± 11 cal/mole, ≮ (i, a) = 32.7° ±2.0°, and Iα = 3.18 ± 0.03 uÅ2.
Structure of the Benzene-Argon Complex in the Gas Phase at 3 Kelvin
Authors: Fung K. H. , Selzle H. L. , Schlag E. W.
Published: February 2015

The structure of the benzene-argon complex is determined from a high resolution band contour of the ν6 transition of the complex measured in a hypersonic jet. It is shown that the argon is located on the main symmetry axis of the benzene molecule. The distance from the center of the benzene ring is found to be 3.4 Å.
An INDO MO Study on the Ground State and the Cationic States of Cyclopentadienyl Nickel Nitrosyl
Authors: Böhm Michael C.
Published: February 2015

The electronic structure of cyclopentadienyl nickel nitrosyl (1) in the ground state as well as the cationic states of 1 are investigated by means of a semiempirical INDO Hamiltonian and many body perturbation theory. It is demonstrated that the nature of the NiNO coupling is largely covalent while the interaction between the 3d center and the cyclopentadienyl ligand is predominantly of ionic type. The ground state MO sequence of the Ni 3d orbitals is 4e2(3dx²-y²/3dxy) below 7e1

(3dXz/3dyz) and 15a1(3dz
2). The sequence of the ionization potentials is 8e1 (Cp - π) < 15a1<4e2<7e1. The ionization energies have been determined by means of the Green’s function formalism; the self-energy part has been calculated by a second order and a renormalized approximation. Both procedures predict the correct sequence of ionization events.
Elementare Herleitung der Dirac-Gleichung. V / Elementary Derivation of the Dirac Equation. V
Authors: Sallhofer Hans
Published: February 2015

The superfluousness of the concept of matter waves is under consideration.
Wavelengths of the M X-Ray Spectra of Uranium, Neptunium, Plutonium, and Americium
Authors: Kleykamp H.
Published: February 2015

The M series of the X-ray spectra of uranium, neptunium, plutonium, and americium have been measured between 250 and 520 pm by means of a linear spectrometer. The relative intensities of the lines have been normalized to the respective Mα1 lines of the actinides.
Investigation of the Nitrogen Hyperfine Structure of Vinylisocyanide by Microwave Fourier Transform Spectroscopy in the X-and Ku-Band
Authors: Bestmann G. , Dreizler H.
Published: February 2015

In memory of W. H. We discuss the features of a microwave Fourier transform spectrometer in the X-and Ku-band as applied to the investigation of the hyperfine structure of rotational transitions. The Nitrogen-hyperfine structure of vinylisocyanide was measured and analysed.
The Concentrational Changes of the Fluorescence Decay Time of Rhodamine B in Ethanol
Authors: Bojarski C. , Żurkowska G. , Tyrzyk J.
Published: February 2015

The photoluminescence decay time τ of neutral solutions of rhodamine B in ethanol was mea-sured for concentrations c from 10-5 mol 1-1 to 10-2 mol 1-1 at 295 K. The τ(C) curve observed is atypical, showing two regions of decreasing r. The drop over the range 4 X 10-4 to 10-3 mol 1-1 was explained by the presence of two ionic forms of rhodamine B, and that at concentrations greater than 4 X 10-3 mol 1-1 - by rhodamine B dimers.
Decay Instability of an Electromagnetic Wave Incident on a Weakly-Inhomogeneous Magnetised Plasma
Authors: Shivamoggi Bhimsen K.
Published: February 2015

This paper considers the parametric decay of an electromagnetic wave incident on a weakly-inhomogeneous magnetised plasma into a Langmuir wave and an ion-acoustic wave. The Vlasov model is used in order to calculate the low-frequency electron-density perturbation produced by the beating of the side-band modes with the pump wave. The results show that the threshold value of the pump wave to undergo a decay instability drops in the presence of an inhomogeneity in the plasma.
Nuclear Quadrupole Perturbations in 51V NMR Spectra of Oxovanadium(+V) Complexes
Authors: Paulsen Kurt , Rehder Dieter
Published: February 2015

Nuclear electric quadrupole coupling constants e2qQ/h have been obtained by evaluation of quadrupole perturbations in 51V NMR spectra of various vanadyl esters and esterchlorides of the general formula VOCl3-n(OR)n (n=0-3; R = Me, Prn , Prn, Bun and Bui). e2qQ/h values have been calculated from (i) 2nd. order quadrupole splittings of the 51V NMR signals in pseudo-polycrastalline samples, (ii) 1st. order quadrupole splittings in nematic liquid crystals and (iii) line widths A ⊿ν1/2 of the 51V and 35Cl NMR signals in the liquid isotropic state and e2qQ/h(35Cl) obtained by pure NQR measurements. The influences of the asymmetry parameter η and the orientation of the crystallites in powder spectra are considered, and temperature and concentration effects upon ⊿ν1/2 and 51V shielding (isotropic phases) and the ordering factor Sa (meso-phases) are discussed.
X-ray Diffraction Study of the Coordination of Fe(III) in a Highly Hydrolyzed Solution of Iron(III) Chloride
Authors: Piccaluga G.
Published: February 2015

A highly hydrolyzed solution of iron(III) chloride is investigated by X-ray diffraction. The occurrence of six O atoms in the first coordination shell of iron(III) is demonstrated. The structural similarity of hydrolyzed solutions of Fe(III) chloride and nitrate is pointed out.
63 Cu NMR Studies of Copper (I) Complexes in Solution: Influence of Anion, Solvent and Temperature on the Linewidth and Chemical Shift of the Copper Resonance
Authors: Kroneck Peter , Kodweiß Jürgen , Lutz Otto , Nolle Alfons , Zepf Daniela
Published: February 2015

The behaviour of the 63Cu nuclear magnetic resonance signals in tetrahedrally coordinated copper(I) complexes has been investigated as a function of temperature, solvent and anion. From the strong dependence of the linewidth and the chemical shift on these parameters, exchange processes with complexes of lower symmetry are concluded.
Influence of pH on the Absorption and Fluorescence Spectra of 6,7-Dihydroxycoumarin in Aqueous Solution
Authors: Grzywacz Jerzy , Taszner Stanisława
Published: February 2015

Absorption and emission spectra of 6,7-dihydroxycoumarin [6,7-DHC] in aqueous solution over a wide pH range are reported. The absorption spectra proved to be strongly sensitive to the pH-value of the solution, whereas the emission spectra change in this range only insignificantly.

An interpretation is attempted on the basis of the differences of the acid-base properties of the 6,7-DHC molecule in its ground and excited singlet state. For this purpose the pKa's and pKa
x's values have been calculated. It has been stated that in the excited state the phototautomer form is very unlikely.
Dielectric Relaxation of Long Molecules in Nematic Host Matrices
Authors: Gerber Paul G.
Published: February 2015

The relaxation times τ of the slowest processes in the parallel dielectric permittivity of various nematic guest-host systems have been measured as a function of temperature. A correlation between τ and its temperature dependence is found, indicating increasing temperature dependence for increasing τ, independent of structural details of the guest molecules or properties of the host matrices which, however, had similar clearing temperatures. Alternations in τ for a homologous series of guest molecules are observed. Increasing host permittivity leads to increased values of τ while the viscous properties of the host show little influence on τ.
Relative Stability of ᗒAl—O—Al ᗕ Linkages in Zeolites. A Nonempirical Molecular Orbital Study
Authors: Sauer Joachim , Engelhardt Günter
Published: February 2015

Nonempirical quantum chemical STO-3G calculations were performed for cluster models of two oxygen-bridged TO4 tetrahedra (T = Si, Al). The models are based on [(HO)3TOT(OH)3]n− structures and, in case of Al-containing models (n = 1,2), their electric neutrality is ensured by adding positive point charges.

The calculations suggest the occurrence of ᗒAl - O -Al ᗕpairings provided certain electric fields act at the corresponding sites.
Notizen: Allowance for a Different Pairing of 5-Fluorouracil
Authors: Giambiagi Myriam S. de , Giambiagi Mario , Esquivel Darci M. S.
Published: February 2015

A different pairing of 5-fluorouracil with adenine and guanine is proposed; this pairing may contribute to explain its mutagenic effect. IEHT charges and bond indices support the assumption.
The Influence of Contact Adsorbed Ions on the Photoelectrochemical Behaviour of α-HgS
Authors: Repenning D. , Schumacher R. , Schindler R. N.
Published: February 2015

Results are reported to describe the influence of additives on the photoelectrochemical properties of the liquid junction α-HgS/electrolyte. The semiconductor electrodes were prepared by sublimation of α-HgS on Au substrates. The electrolyte was modified by additives such as Cl-, Br-, J-, and CN- ions. It was found that these anions play an important role in determining the flat band Vfb and the transition potential Vtr. Generally, both the nature and the concentration of the additives affect Vfb and Vtr.The results are interpreted in terms of contact adsorption of the used anions. It is further indicated that the adsorptive properties can be correlated to a possible chemical reaction of mercury cations with halide anions to form insoluble layers at the surface.
Notizen:On the Behaviour of Light in a Spherically Symmetric Aether Field
Authors: Sjödin Torgny
Published: February 2015

The formulae for the bending of light and retardation of light signals near point masses are obtained in a very simple and natural way making use of classical optics. This is accomplished by characterizing the aether density in each point through a refraction index and assuming that the velocity of light is inversely proportional to this index. The results agree with General Relativity and with made experiments.
X-Ray Attenuation Coefficients for Copper in the Energy Range 5 to 50 ke V
Authors: Gerward L.
Published: February 2015

X-ray mass attenuation coefficients for polycrystalline samples of copper have been measured with a high-precision energy-dispersive method. Estimates of the scattering contributions to the attenuation coefficients are made. The photoelectric coefficients deduced from the experimental results are compared with theoretical calculations using screened hydrogen-like eigenfunctions as well as more rigorous relativistic wavefunctions.
On Secondary Extinction
Authors: Kato N.
Published: February 2015

For the purpose of extinction correction in crystal analysis, the secondary extinction factor y is discussed in the light of the new approach developed by the present author. The mosaic crystal model is adopted. A comparison is made between the present theory and the conventional theory (CT) through functional analysis of y in general cases and numerical analysis in the special case of parallel slab crystals. The y values of CT are underestimated by about 4% and 30% at y = 0.5 and 0.15, respectively. For y ≿ 0.7, CT is practically correct.
A Comparative X-Ray Diffraction Study of Aqueous MnSO4 and Crystals of MnSO4·5H2O
Authors: Caminiti R. , Marongiu G. , Paschina G.
Published: February 2015

X-ray single crystal analysis of MnSO4·5H2O shows that the manganese atoms are octahedrally coordinated by oxygen atoms, four of which belong to water molecules and two to sulphate groups.

A model derived from the crystal structure was fitted to the X-ray scattering intensities from aqueous MnSO4. Good agreement with experimental data is achieved using a model in which Mn(H2O)6-z(OSO3)z
+2-2z interacts with about ten water molecules and each sulphate ion with about seven water molecules.
Amorphous Fe72Cr8P13C7 Powder with High Corrosion Resistance
Authors: Cho Kangjo , Hwang Choll-Hong , Pak Chang-Su , Ryeom Yeong-Jo
Published: February 2015

Amorphous Fe72Cr8P13C7 powder has been prepared by the spark erosion technique and its corrosion behavior investigated potentiodynamically. It is concluded that the powder prepared this way possesses a relatively high corrosion resistance, as does amorphous Fe72Cr8P13C7 ribbon prepared by rapid quenching.
Experimental Verification of the Theory on Rotational Motions of Prolate Luminescent Molecules in Solution
Authors: Kawski A. , Kukielski J. , Alicka M. , Kubicki A. , Waśniewski T.
Published: February 2015

Theories I [1] and II [2] on rotational motions of prolate molecules in solvents of different viscosities were verified for a series of luminescent compounds, the transition moments of which lie along their longer axes. Better agreement between the experimental and theoretical results was found with theory I. Effective volumes and moments of inertia were determined for the molecules studied.
Ionization of Organic Molecules by Fast Molecular Ion Bombardment
Authors: Wong S. S. , Stoll R. , Röllgen F. W.
Published: February 2015

The bombardment of organic samples by the ionization products of trimethyl-pentaphenyl trisiloxane was found to have a strong effect on the sputtering yield of molecular parent ions of thermally labile compounds. For the tetra-saccharide stachyose an order of magnitude higher yield was obtained with fast molecular ion than with fast Hg atom bombardment. This difference decreased from tetra to disaceharides and was smallest for arginine.
Alfvén’s Critical Velocity Effect Tested in Space
Authors: Haerendel Gerhard
Published: February 2015

A sounding rocket experiment involving the injection of a barium gas jet in the upper ionosphere provided an opportunity of investigating quantitatively several aspects of the beam-plasma interaction that is the substance of Alfven’s critical velocity effect. Whereas the experimental data are presented elsewhere, this paper contains some theoretical considerations of (1) the limiting neutral density for which the ionization process can operate, (2) the interaction of the freshly injected ions with the background plasma, and (3) the microprocess which leads to collisionless electron tail formation. The observed distribution of injected ions is consistent with the Townsend condition on the beam-plasma discharge. The mass loading on the ambient plasma, although locally high, has a weak effect on the dynamics of the involved flux-tube because of the limited extent of the beam. The most likely process by which energy is transferred from the freshly generated ions to the electrons is an ion beam instability leading to the excitation of lower hybrid waves
Generation of Mean Flows in a Rotating Convection Layer
Authors: Busse F. H.
Published: February 2015

The instability of convection rolls in a fluid layer heatet from below is studied in the case where the layer rotates about an axis slightly inclined with respect to the vertical. The inclination destroys the horizontal isotropy of the layer, but the instability of rolls found by Küppers and Lortz [1] is little affected as long as the angle of inclination is small. A new effect is the generation of mean Reynolds stresses by rolls not aligned with the horizontal component of the rotation vector. The mean flow exhibits a vorticity of the same sign as the horizontal component of rotation and agrees qualitatively with the mean flow found in the numerical experiments of Hathaway and Somerville [2]
Dynamics of a Resistive Sheet Pinch
Authors: Biskamp D.
Published: February 2015

The dynamic evolution and the saturated state of a long sheet pinch subject to growth of resistive tearing modes was investigated by numerical solution of the 2D MHD equations. Both the compressible and the incompressible equations were used, and the difference is found to be negligible. The necessity of considering a resistive equilibrium is stressed. The paper concentrates on a static equilibrium maintained by an external electric field and requiring a special distribution of the resistivity η. In addition the dynamics of the resistivity plays an important part. Assuming η to be time independent, the sheet pinch develops a number of soliton-like magnetic islands, which coalesce. The final state consists of a single soliton, while the generation of further sol-itons is inhibited by a strong shear flow allong the current sheet. When allowance is made for parallel diffusion of the resistivity such that η is essentially a flux function, the final state is quite different. Here the longest wavelength dominates, leading to a single, large island and completely destroying the original sheet pinch
The Magnetohydrostatic Boundary Value Problem Without Symmetry
Authors: Lortz D.
Published: February 2015

The magnetohydrostatic boundary value problem is investigated for the case where the magnetic field is tangential on an toroidal surface without symmetry. The first part deals wit small deviations from the homogeneous field. If the surface deviation from a cylinder with arbitrary cross-section is small of order ε, it is found that in first order a solution exists if two profile functions are properly prescribed. The solubility condition in the (n + 1)-th order determines the freedom of the n-th order. In the second part general toroidal geometry is considered for the case of a smooth pressure profile. The longitudinal current is determined so that the rotational transform vanishes
Numerical Evaluation of Neoclassical Transport in Stellarators at Arbitrary Collisionality
Authors: Wobig H.
Published: February 2015

The neoclassical diffusion losses of an l = 2 stellarator and an advanced stellarator are analysed with a modified version of the Boozer-Kuo-Petravic Monte-Carlo Code. Particle loss and confinement of a monoenergetic ion distribution are determined at arbitrary collisionality under stationary conditions. Special attention is given to the long mean free path regime. Due to the drift motion of localized particles a depopulation of the distribution function around v∥ = 0 occurs. The confinement time is determined by pitch angle scattering in this case. It is analysed under which conditions the 1/v-scaling of diffusion losses arises. A comparison is made between the loss rate of an advanced stellarator and a classical l = 2-stellarator. Also a tokamak with ripple losses is considered
ZEPHYR, the Concept of a Compact Ignition Experiment
Authors: Andelfinger C. , Kaufmann M. , Köppendörfer W. , Lackner K.
Published: February 2015

The paper describes the physics background and the design of a compact ignition and burn control experiment (ZEPHYR). It was optimized with respect to magnetic field energy and costs on the basis of a cryogenically cooled normal conducting magnet. Ohmic heating, neutral injection and adiabatic compression were chosen to produce the required temperature. Ignition and controlled thermonuclear burn for about ten energy confinement times were foreseen
Miscibility Gaps in Fused Salts. Note XII. Systems Formed with Thallium (I) Halides and Lithium or Sodium Halides: the Ternary Li, Tl/Cl, I
Authors: Flor Giorgio , Margheritis Chiara , Vigano’ Giuseppina Campari , Sinistri Cesare
Published: February 2015

Demixing was investigated in the molten salt families formed with thallium (I) halides and lithium or sodium halides. Measurements were carried out on the twelve stable diagonals of the corresponding reciprocal ternary mixtures. Liquid-liquid equilibria were found in the three systems TlCl+LiF, TlBr+LiF and TlI+LiCl while in the two systems formed with Til and LiF or NaF measurements could not be carried out owing to the thermal instability of Til.

The reciprocal ternary Li, Tl/Cl, I exhibits demixing in a temperature range which is convenient for investigation: therefore the whole composition square was studied. The upper critical solution point of the gap lies along the stable diagonal at 734°C and xLiCl = 0.58. The projection of the stratification lens occupies 38.8% of the composition square. Moreover an “a priori” prediction of the liquid-liquid equilibria was carried out by means of the conformal ionic solutiontheory.
The Extended Korteweg-de Vries Equation
Authors: Hefter E. F.
Published: February 2015

A slight and natural extension of the traditional Korteweg-de Vries equation (KdV) allows all (or groups) of its solitons to have the same velocity thus facilitating the application of the KdV to realistic quantum mechanical problems.
Compton Cross Section of 662 keV Photons from the K-shell of Co, Cu, Ge, Nb, Mo and Ag
Authors: Eichler J. , Barros S. de , Conçalves A. M.
Published: February 2015

From the intensity of K x-rays produced by 662 keV photons the sum of the total cross sections of the photoelectric and Compton effects on this shell is obtained for the atoms with Z = 27, 29, 32, 41, 42 and 47. The contribution of the photoeffect is about 15% for Co(Z = 27), 50% for Mo (Z = 42) and 70% for Ag(Z = 47). Using theoretical cross section for the photoeffect the total Compton cross section on the K-shell is evaluated. The results agree with the free electron value.
Notizen: Solitary Front-like Wave Solutions of the Korteweg-de Vries-Burgers′ Equation
Authors: Lakshmanan M. , Ganesan S.
Published: February 2015

Existence of a class of well-behaved solitary front-like wave solutions having arbitrary velocities for the Kortewegde Vries-Burgers′ equation is pointed out. These solutions are analogous to the solitary wave solutions occurring in other well known nonlinear diffusive systems.
X-Ray Diffraction Study on Hydration and Ion-Pairing in Aqueous ZnSO4 Solution
Authors: Radnai T. , Pálinkás G. , Caminiti R.
Published: February 2015

An X-ray diffraction experiment on a 2.98 molar ZnSO4 aqueous solution has been interpreted in terms of coordination models. The best agreement between model and experimental structure functions was reached when the Zn2+ ion is hydrated in octahedral form, with twelve water molecules in a second hydration shell, bonded by shortened H-bonds to the first hydration shell. The sulfate group is loosely coordinated by 8.2 water molecules. Besides the dominating Zn(H2O)2+
6 complexes, about 40% [Zn(H2O)5SO4] inner complexes were found to be consistent with the X-ray data. Alternative models of cationic hydration are critically examined and for the sulfate group the independent atom approximation is compared with a spherical molecular description.
Phase Transition Studies in Polymesomorphic Compounds II. Ultrasonic Velocity Studies in N(p-n-Heptyloxy Benzylidene)p-n-Butyl Aniline
Authors: Pisipati V. G. K. M. , Rao N. V. S.
Published: February 2015

The variation of ultrasonic velocity in N (p-n-heptyloxy benzylidene)p-n-butyl aniline, (HyBBA) with temperature in isotropic, nematic, smectic-A, smectic-C and smectic-G phases is measured. All the phase transitions I-N, N-SA, SA-SC and SC-SG are found to be of first order. The adiabatic compressibility βad, molar sound velocity or Rao number Rn, and molar compressibility or Wada constant AW are computed. Rn and AW of HyBBA are compared with theoretical values and found to be in good agreement with the theory.
Harmonic Force Field and Mean Amplitudes for C4Cl4 and C4F4 Compounds
Authors: Díaz G.
Published: February 2015

Normal coordinate treatment of C4F4 and C4Cl4 in the GVFF was performed using published vibrational frequencies. The vibrational assignment for these molecules is discussed. Calculated mean amplitudes for both molecules are reported.
Electrical Resistivity of Metals at Low Temperatures
Authors: Bohn H.-J. , Simon G.
Published: February 2015

For the system of the coupled Boltzmann transport equations for electrons, phonons and impurities in metals the influence of the crosscoupling terms is investigated. It is shown that this results at low temperatures in a contribution to the electrical resistivity proportional to 1/√T. This is due to the fact that by phonon-impurity scattering the phonon-drag contribution is influenced by the presence of the impurities. A comparison with recently published experimental work is made.
Frequencies and Normal Modes of Vibration of Benz[a]anthracene Radical Ions
Authors: Kubba Rehab M. , Al-ani Raghida I. , Shanshal Muthana
Published: February 2015

MINDO/3-FORCES calculations were carried out for the radical ions of benz[a]anthracene. Both ions exhibit Cs symmetry with C-C bond alternation in all four rings. The obtained equilibrium geometry was applied for the calculation of all 3N − 6 vibration frequencies of each ion, and for the analysis of their normal coordinates. The so calculated frequencies of the radical cation were close to the experimental frequencies and those of the ab initio calculations. They fall in the ranges νCHstr. (3034 - 3087 cm−1), νCCstr. (1237 - 1609 cm−1), δCH (1142 - 1216 cm−1). Interesting correlations could be obtained for the frequencies of similar vibrations, e. g. νsymCHstr. >νasymCHstr. Exception is the frequency of vibration of CHα in ring A for the radical cation and the same bond in ring D for the radical anion. The vibration frequencies for the CH bonds depend on the σ -electron densities of the corresponding carbon atoms, i. e. νCH.+str. >νCHstr. >νCH.−str., where σ −ρĊ
+ >σ −ρC >σ −ρĊ
− . For the C-C stretching vibrations the relation ν(C-C)str. >ν(C-C).−str. >ν(C-C).+str. holds, with the exception of the Cβ -Cβ bond, for which the relation ν(C-C)str. >ν(C-C).+str. >ν(C-C).−str. is found. As for the in-plane and out of-plane deformations, the following general correlations δ (CH) >δ (CH).− >δ (CH).+ and γ (CC) >γ (CC).− >γ (CC).+.
Investigations Of The Epr G Factors Of Nacrs2 And Nacrse2
Authors: Wu Xiao-Xuan , Zheng Wen-Chen , Zhou Qing , Mei Yang
Published: February 2015

The EPR g factors of Cr3+ in NaCrS2 and NaCrSe2 crystals are calculated from the high-order perturbation formulas based on the one-spin-orbit (SO)-coupling-parameter (i. e., the SO-couplingparameter of the central 3dn ion) as well as the two-SO-coupling-parameter (i. e., the SO-couplingparameter of the 3dn ion and that of ligands) models for 3dn ions in cubic octahedral sites. The calculated results (in particular for NaCrSe2) based on the two-SO-coupling-parameter model are closer to the observed values than those based on the one-SO-coupling-parameter model, suggesting that for calculations of the g factor of 3dn ions in covalent crystals the two-SO-coupling-parameter model is preferable to the one-SO-coupling-parameter model. The reasonableness of the calculated results from the two-SO-coupling-parameter model is discussed.
IR Spectroscopic Study of M(Benzoic Acid)2Ni(CN)4·(1,4-Dioxane) Clathrate (M = Ni, Cd and Co)
Authors: Kartal Zeki
Published: February 2015

In this study, clathrate of benzoic acid-tetracyanonickel, given by the formula M(benzoic acid)2Ni(CN)4・(1,4-dioxane) (M = Ni, Cd and Co), is obtained for the first time through chemical methods. The similarities of the observed spectra indicate that the obtained clathrate of benzoic acidtetracyanonickel is a new example of Hofmann-type clathrates. - PACS numbers: 33.20.Ea, 33.20.Tp
Electron Momentum Density In Europium Using A 137Cs Compton Spectrometer
Authors: Ahuja Babu Lal , Malhotra Harsh , Mathur Sonal
Published: February 2015

The isotropic Compton profile of europium, the most reactive lanthanide, has been measured at a resolution of 0.40 a.u. using 661.65 keV gamma-rays. In the absence of a band structure-based Compton profile, the experimental data are compared with renormalised-free-atom (RFA) and free electron models. It is seen that the RFA model with e−-e− correlation agrees better with the experiment than the free electron models. The first derivatives of the Compton profiles show the hybridization effects of s-, p-, d-, f-electrons. From our RFA data we have also computed the cohesive energy of europium. PACS: 13.60.F, 71.15.Nc, 78.70. -g, 78.70.Ck
Preparation and Study of Heterojunctions Based on Chalcogenide Glassy Semiconductors
Authors: Kornev Konstantin P. , Korneva Irina P.
Published: February 2015

Four types of heterojunctions were prepared: SnO2-As2(Se0.9Te0.1)3, SnO2-(As0.67Sb0.33)2Se3, n-GaAs-As2Se3 and n-GaAs-As2S3. For all samples I-V characteristics and photosensitivity spectra were obtained. These heterostructures can be used for manufacturing rectifying devices and photoreceivers.
EPR of Gamma-irradiated L-Glutamine Hydrochloride and N-Carbamoyl-L-glutamic Acid
Authors: Osmanoğlua Şemsettin , Aydın Murat , Başkana M. Halim
Published: February 2015

The electron paramagnetic resonance spectra of γ -irradiated L-glutamine hydrochloride and N-carbamoyl- L-glutamic acid single crystals have been investigated at room temperature. Radiation damage centres are attributed to ĊH, ṄH2 and CH2Ċ(NH2)COOH radicals.
Bäcklund Transformations for Fifth-order Painlevé Equations
Authors: Sakka Ayman Hashem
Published: February 2015

In this article we study Bäcklund transformations of the fifth-order Painlevé equations Fif-I, Fif-II, Fif-III and Fif-IV. We derive Bäcklund transformations between these equations and new fifth-order Painlevé equations. The method of derivation is based on the idea of seeking transformations that preserve the Painlevé property. Moreover we give first integrals for the new equations. - MSC2000 classification scheme numbers: 34M55, 35Q51, 37K35
EPR Parameters of the Trigonal Fe+
Ga-SP Pair Defect in n-Type GaP Codoped with Iron and Sulphur
Authors: Wu Xiao-Xuan , Zheng Wen-Chen , Zhou Qing , Mei Yang
Published: February 2015

The EPR parameters (g factors gII, g⊥, and zero-field splitting D) of a trigonal Fe+ center (which is assigned to a donor-acceptor pair defect Fe+
Ga-SP caused by S2− at a nearest-neighbor P3− site of an Fe+
Ga impurity) in n-type GaP codoped with iron and sulphur are calculated from high-order perturbation formulas based on the two spin-orbit coupling parameter model for the EPR parameters of a 3d7 ion in trigonal symmetry. The calculated results agree well with the observed values, suggesting that the assignment is suitable
(Tnmethylphosphine)(triphenylsilyl)gold(I) and Related Compounds
Authors: Oroz Miguel Monge , Schier Annette , Schmidbaur Hubert
Published: February 2015

Mononuclear coordination compounds of the type (R3P)AuSiR′3 with R = R’ = Ph and R = Me, R′ = Ph have been obtained from reactions of the corresponding halide complexes (R3P)AuCl with the silyllithium reagent LiSiPh3. The fully phenylated species undergoes ligand redistribution in solution to give homoleptic ionic species. (Me3P)AuSiPh3 is less susceptible to this process and crystallizes from solutions as the heteroleptic complex. The crystal structure of this compound has been determined by X-ray diffraction. In the crystal lattice the molecules are not associated.
Diphenyl(2-hydroxy-phenyl)phosphine and its Trimethylsilyl Ether as Ligands for Gold(I) Complexes
Authors: Hollatz Christian , Schier Annette , Schmidbaur Hubert
Published: February 2015

Diphenyl(2-hydroxy-phenyl)phosphine was introduced as a ligand for gold(I) halides and pentafluorophenyl gold(I) in order to probe the interplay of intra- and intermolecular interactions based on aurophilic (Au· · ·Au) and hydrogen bonding. 1:1 complexes of the type Ph2(2-HO-C6H4)P-Au-X with X = Cl, Br, C6F5 have been prepared and characterized by analytical and spectroscopic data. The crystal structure of the chloro complex (1) has been determined. In the lattice the molecules form dimers through O-H· · ·Cl hydrogen bonds. Au· · ·Au contacts are ruled out by steric congestion. Reaction of 1 with triethylamine yields a 1:1 adduct with O-H· · ·NEt3 hydrogen bonding. The trimethylsilyl ether of the title ligand also forms 1:1 complexes with AuCl, AuBr, Aul, and AuC6F5. The crystal structures of the chloro (5) and iodo (7) compound have been determined. In both cases the lattices are built from monomers which show only minor differences in their conformations. The silylether groups are not acting as intra- or intermolecular donor functions to the gold atoms.
Oligonuclear Tricarbonylchromium- and Tricarbonyltungsten Derivatives of Tris(1-cyclohepta-2,4,6-trienyl)phosphane, P(C7H7)3, and Related Ligands
Authors: Herberhold Max , Bauer Kurt , Milius Wolfgang
Published: February 2015

A series of trinuclear carbonylmetal complexes of tri(1-cyclohepta-2,4,6-trienyl)phosphane, P(C7H7)3 (1), has been prepared by the reaction of P(SiMe3)3 with η7-tropylium halfsandwich salts, [(η7-C7H7)M(CO)3]BF4, (M = Cr, Mo, W). While phosphorus remains uncoordinated in the chromium complex P[(η6-C7H7)Cr(CO)3]3 (2a), the molybdenum and tungsten analogues,

(M = Mo (2b), W (2c)), contain a coordinated phosphorus atom together with a η4-norcaradienyl substituent. Reaction of 2a with pentacarbonylmetal fragments, [M(CO)5], leads to trinuclear products,

- (CO)4][(η-C7H7)M(CO)3]2 (M = Cr (5a), W (5c)), in which phosphorus is coordinated next to an η2-cycloheptatrienyl substituent. Several alkyl- and arylphosphanes containing [(η6-C7H7)Cr(CO)3] substituents (X), e. g. Ph2P(X) (6a), RP(X)2 (R = Me (7a), CH2Ph (8a), Ph (9a)) and (X)2P(R')P(X)2 (R' = methylene (10a) or ο-phenylene (11a)), have also been synthesized. The chromium complexes 6a - 11a contain an uncoordinated phosphorus center, but in contrast to 9a, the corresponding tungsten compound PhP

(9c) has again a structure similar to 2c. The arsenic complexes, As[(η6-C7H7)M(CO)3]3 (M = Cr (12a), W (12c)) both contain an uncoordinated arsenic center, analogous to 2a. The molecular structures of all new complexes in solution at room temperature were deduced from a consistent set of 1H, 13C and 31P NMR data, and X-ray structure determinations were carried out for 2a and 5c.
Di- bis Pentahydrate von fünf Alkylendiaminen. Eine Fallstudie zu ein- und zweidimensionalen Wasserpolymeren in Festkörpern/Di- to Pentahydrates of Five Alkylenediamines. A Case Study of One- and Two-Dimensional Water Polymers in Solids
Authors: Janeda Stephanie , Mootz Dietrich
Published: February 2015

The crystal structures of five low-melting hydrates of n-alkane-α,ω-diamines, H2N(CH2)nNH2 · x H2O, for short Cn · x W, have been determined. As a common feature, the water molecules are mutually linked by hydrogen bonds O-H· · ·O to form low-dimensional polymers. These are a meandering chain in C2 · 2 W (space group I 2/a, Z = 4 formula units per unit cell), a zig zag chain in C6 · 2 W (P 21/c, Z = 2), a ribbon of consecutively condensed five-membered rings in C3 · 3 W (P 21/c, Z = 4) and a layer of condensed and spiro-linked rings of varying size each in C7 · 3 W (P 1̄, Z = 4) and C4 · 5 W (C 2/c, Z = 4). Further hydrogen bonding, between the water polymers and the bifunctional amine molecules, leads to overall connectivities which are three-dimensional in each structure.
Excitonic Bands in the Optical Absorption Spectra of (Bu4N)CuBr2, (Et4N)2Cu2Br4, (Pr4N)2Cu4Br6, (Bu4N)2Cu2I4, (Me4N)Cu2I3, (Pr4N)4Ag4I8, (Me4N)Ag2I3, (Et4N)Ag2Br3, and Similar Compounds
Authors: Papavassilioua G. C. , Mousdis G. A. , Terzis A. , Raptopoulou C. P.
Published: February 2015

The title compounds (natural low-dimensional semiconductor systems) exhibit strong excitonic optical absorption bands in the UV spectral region, because of the quantum confinement of excitons, as in the cases of bivalent-metal and trivalent-metal halide complexes. The excitonic bands are shifted to longer wavelengths, approaching those of the corresponding bulk materials, as the anion-size or the anion-dimensionality increases.
Notizen: Untersuchungen an Polyhalogeniden, XXXIX. [(H3O)(18-Krone-6)]I7, eine Struktur-Neubestimmung/Studies on Polyhalides, XXXIX. Structure Refinement of [(H3O)(18-crow n-6)]I7
Authors: Khalika Sawsan Abd El , Essawia Mervat El , Dombrowskih Ingo , Tebbeb Karl-Friedrich
Published: February 2015

The structure analysis of the compound [(H3O)(18-Krone-6)]I7 has been repeated. The already known structure could now be described with improved precision. The unique polyiodide chain 1
∞[(I-·2I2)I2] may be derived from the regular three dimensional iodide-iodine lattice 1
∞[I-3I2] by separation.
Die Kristallstruktur von [PhMe3 N]4 [Pb3Br10] / Crystal Structure of [PhMe3N]4[Pb3B r10]
Authors: Wiest Th. , Blachnik R. , Reuter H.
Published: February 2015

[PhMe3N]4[Pb3Br10] crystallizes with monoclinic symmetry in the space group P 2 1/c with lattice parameters of a - 1295.5, b - 951.5, c = 2294.7 pm, ß = 110.24° and Z = 2. The unit cell contains eight cations and two [Pb3Br10]4- anions, each of which shares four vertices with neighbouring anions resulting in a twodimensional anionic partial structure of the Cs4Mg3F10 type.
The Crystal Structure of WC Type ZrTe. Advantages in Chemical Bonding as Contrasted to NiAs Type ZrTe
Authors: Örlygsson Gissur , Harbrecht Bernd
Published: February 2015

Single crystals of WC type ZrTe were prepared from the elements. A single crystal structure determination of this structure type was performed for the first time: ZrTe (WC) crystallizes in the hexagonal space group P6̄m2 (No. 187), hP2, Z - 1, a - 377.06(5), c = 386.05(8) pm; 84 reflections, 5 variables, R(F) = 0.037. The distinctions in bonding for ZrTe (WC) and a hypothetical stoichiometric ZrTe crystallizing in the NiAs type structure were analyzed on the basis of extended Hückel calculations. Heteronuclear interactions contribute most strongly to the stability of both structures. Attractive Zr-Zr interactions energetically favour ZrTe (WC) relative to ZrTe (NiAs). The Fermi level of ZrTe (WC) resides in a local minimum of the DOS, whereas that of ZrTe (NiAs) intersects a local DOS maximum, and is pushed up by about 0.5 eV, expressing the decisive destabilization of NiAs type ZrTe. As a consequence, metal deficiency is observed for ZrTe (NiAs), in contrast to ZrTe (WC).
Reaktionsverhalten von β-Oxo-carbonsäurederivaten der Anthracenreihe bei der Synthese von Pyrazolen / On the Reaction Behavior of ß-Oxo Carbonic Acid Derivatives of the Anthracene Series in Pyrazole Synthesis
Authors: Knieß Astrid , Gruner Margit , Mayer Roland
Published: February 2015

ß-Oxo-1 and 9-anthracenepropionate (6 and 7) reacts with DMF-acetale to enaminones 10 and 11. The reaction of 2-(dimethylamino)methylen-substituted ß-oxo-1 -anthracenepropionate (10) with hydrazines yields 5-(l-anthracenyl)-pyrazol-4-carboxylates (13). In contrast, the cyclocondensation of 3-(9-anthracenyl)-2-(dimethylamino)methylen-3-oxo-propionate (11) with hydrazine hydrochlorides gives 4-(9-anthracenoyl)-5-hydroxy-pyrazoles (14). This is caused by the sterical hindrance of the carbonyl group of the anthracene derivatives in position 9; thus, the cyclocondensation proceeds via reaction of the ester group of the enaminone 11.
Structure and Properties of the Stannide Eu2Au2Sn5, and its Relationship with the Family of BaAl4-Related Structures
Authors: Kußmann Dirk , Pöttgen Rainer , Rodewald Ute Ch. , Rosenhahn Carsten , Mosel Bernd D. , Kotzyba Gunter , Künnen Bernd
Published: February 2015

The stannide Eu2Au2Sn5 was prepared by high-frequency melting of the elements in a sealed tantalum tube. The structure of Eu2Au2Sn5 was refined from single crystal X-ray data: P21/m, a = 928.6(2), b = 465.8(2), c = 1042.9(3) pm, ß = 92.28(2)°, wR2 = 0.0653, 1220 F2 values and 56 variables. The structure of Eu2Au2Sn5 is of a new type, it can be considered as an ordered defect variant of the BaAl4 type. Due to the ordered defects, the coordination number (CN) of the two crystallographically different europium sites is reduced from CN 16 to CN 14. The gold and tin atoms in Eu2Au2Sn5 form a complex three-dimensional [Au2Sn5] polyanion in which the europium atoms are embedded. Within the polyanion short Au-Sn and Sn-Sn distances are indicative of strongly bonding Au-Sn and Sn-Sn interactions. A detailed group-subgroup scheme for various ordered and defect variants of the BaAl4 family is presented. Eu2Au2Sn5 shows Curie-Weiss behavior above 50 K with an experimental magnetic moment of 7.90(5) μB/Eu, indicating divalent europium. Antiferromagnetic ordering is detected at 5.8(5) K at low fields and a metamagnetic transition occurs at a critical field of 1.4(2) T. Eu2Au2Sn5 is a metal with a specific resistivity of 150±20 μfΩcm at room temperature. The results of 151Eu and 119Sn Mössbauer spectroscopic experiments are compatible with divalent europium and show complex hyperfine field splitting with a transferred magnetic hyperfine field at the tin nuclei at low temperature.
Synthesis, Characterization and Crystal Structures of 1,2-Disubstituted Ferrocenyl Stibines
Authors: Pérez Diego , Sharma Pankaj , Ortiz Ana M. , Cabrera Armando , Hernández Simon , Toscano Alfredo , Gutiérrez René
Published: February 2015

New 1,2-disubstituted ferrocenyl stibines containing a -CH2OR pendant arm were synthesized and characterized by various spectral and analytical methods. Nucleophilic substitution of rac-diphenyl[( 2-trimethylammoniomethylferrocen-1-yl)]stibine iodide by methanol produces compound Fc(CH2OMe)SbPh2 (1). The acetylation of diphenyl(2-dimethylaminomethylferrocen-1-yl)stibine by acetic anhydride affords compound Fc(CH2OCOCH3)SbPh2 (2), which on further reaction with sodium hydroxide affords the alcohol Fc(CH2OH)SbPh2 (3). The molecular structures of the stibines 1, 2 and 3 were determined by X-ray crystallography. None of the heterobimetallic compounds containing a -CH2OR arm shows hypervalent interactions in the solid state. By contrast, hypervalent interactions were found in ferrocenyl stibines with a -CH2NR2 pendant arm.
A New Lindqvist Polyanion-based Three-dimensional Network with a NaCl Topology
Authors: Li Shaobin , Pang Haijun , Ma Huiyuan , Wang Kun , Zhu Chuncheng
Published: February 2015

A new compound [Co(bipy)3][Mo6O19]·H2O (1) (bipy = 2,2´ -bipyridine) has been synthesized under hydrothermal conditions and characterized by IR spectroscopy, TG analysis and single-crystal X-ray diffraction. The crystal structure consists of a [Co(bipy)3]2+ cation, an [Mo6O19]2− anion, and a water molecule. In 1 each [Co(bipy)3]2+ cation is surrounded by six [Mo6O19]2− anions and vice versa in a cubic face-centered close packing array, forming a 3D architecture with NaCl topology. Cations and anions are connected via weak hydrogen bonds in which also the water molecule participates. The luminescent and electrochemical properties of the title compound have also been studied.