bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation of Crystal Structure and Vapor Composition of Metal Dihalides
Authors: Hargittai Magdolna , Jancsó Gábor
Published: February 2015

The presence of dimers in the vapor of metal dihalides, as seen in electron diffraction experiments, is found to be correlated with the crystal structure of the halide and with the difference in the heat of vaporization between monomers and dimers. If the dimeric molecule cannot be recognized as a unit in the crystal, dimers are not detected in the vapor. If dimeric molecules are discernible in the crystal, they will be observed in the vapor if their heat of vaporization is not greater than that of the monomer by more than 10 kcal/mol.
Ionic Diffusion in Cu6PS5Br Studied by 63Cu NMR
Authors: Ohki H. , Harazono K. , Erata T. , Tasaki A. , Ikeda R.
Published: February 2015

Applying 63Cu NMR technique, we observed exchange between the nonequivalent copper sites in crystalline Cu6PS5Br, known as a member of the mineral "argyrodite". Below 200 K, where the motion of the copper (I) ion is slow, we could distinguish several nonequivalent copper sites. On increasing the temperature, the chemical exchange between the nonequivalent cation sites was seen on the 63Cu NMR spectra. We could determine the activation energy for this motion to be 35 kJ mol-1 , in good agreement with the published ionic conductivity.
Perturbation Dynamics of the Infinite Dicke Model
Authors: Honegger Reinhard , Rieckers Alfred , Unnerstall Thomas
Published: February 2015

By means of operator algebraic methods the dynamics of the Dicke model is investigated in the limit where the number of the two-level atoms goes to infinity and the interaction strength remains on a finite level. The infinite atomic system is treated as a mean field quantum lattice system. It is shown that the limiting dynamics is essentially determined by the collective behaviour of the atoms. With Trotter's product formula and perturbation theoretical methods we obtain explicit expressions for the unitary time evolution operators in the uncoupled representation.
Small Angle Neutron Scattering with Hydrogenated Amorphous Cu50 Ti50 and Ni-Ti-Si Alloys
Authors: Lamparter P. , Boucher B.
Published: February 2015

The metallic glasses Cu50Ti50, Ni30Ti60Si10, Ni32Ti52Si16 , Ni16Ti68Si16 and Ti84Si16 were produced by melt spinning. The alloys in the blank state as well as after loading with hydrogen or deuterium were investigated by small angle neutron (SANS) and X-ray (SAXS) scattering. The scattering of the different amorphous alloys exhibited common features. SANS follows a power-law with exponent of the scattering vector between -3 and -4. The melt-spun glasses contain extended structural inhomogeneities which are associated rather with the local composition than with the local density. SAXS measurements did not show effects above the background level.

Loading the alloys with hydrogen or deuterium causes strong effects in the SANS behaviour. From the results it is concluded that the amorphous alloys contain inner surfaces where the hydrogen atoms segregate.
The Microwave Spectrum of 2,6-Lutidine, Analysis of Internal Rotation and 14 N Hyperfine Structure
Authors: Thomsen C. , Dreizler H.
Published: February 2015

The rotational spectrum of 2,6-lutidine, (CH3)2C5H3N, has been recorded between 6 and 26.5 GHz using pulsed molecular beam microwave Fourier transform spectroscopy. The rotational constants are A = 3509.7139(84) MHz, B = 1906.8639(101) MHz, and C = 1254.6215(14) MHz, the barrier to internal rotation of the two methyl groups is V3 = 1.1752 kJ/mol, their moments of inertia were found to be Iα = 3.0808(9) uÅ2 . The nitrogen nuclear quadrupole constants are χaa = +1.600(5) MHz, χbb = -4.572(3) MHz and χcc = +2.972(5) MHz.
The Microwave Spectrum of the Thiophene-Argon van der Waals Complex
Authors: Kretschmer U. , Stahl W. , Dreizler H.
Published: February 2015

The rotational spectra of the 32S-and 34S-thiophene-argon complex have been studied in the microwave region between 6 and 18 GHz using a pulsed molecular beam Fourier transform micro-wave spectrometer. The rotational and centrifugal distortion constants of the 32S-thiophene-argon complex were found to be A = 3280.38865(15) MHz, B = 1203.32018(15) MHz, C = 1123.45120(11) MHz, ΔJ = 3.3311 (33) kHz, ΔJK = 16.9015(31) kHz, ΔK = -18.302(14) kHz, δj = 0.235074(86) kHz, δK = 4.340(33) kHz. For the 34S-isotopomer A = 3231.16878(15) MHz, B = 1194.05602(58) MHz and C = 1109.53497(30) MHz with almost the same centrifugal distortion constants were obtained. The argon atom is placed 3.59 Å above the ring plane.
High Resolution IR-Spectra of Furane and Thiophene
Authors: Pankoke B. , Yamada K. M. T. , Winnewisser G.
Published: February 2015

Åbstract

The spectra of the out-of-plane fundamental band of furane (C4H4O) centered at 744 cm -1 and of thiophene (C4H4S) at 712 cm -1 were measured in Doppler-limited resolution with a diode-laser spectrometer at Köln and with a high-resolution Fourier transform spectrometer at the University of Gießen. An interactive Loomis-Wood program was applied to identify the c-type transitions of furane and thiophene. The molecular parameters were determined from the observed line positions and the available microwave data by least-squares-fits using Watson's A-reduced Hamiltonian. Some relations among parameters appearing in different formulations of the Hamiltonian are represented explicitly in connection with the derivation of the unreduced constants. The unreduced constants were derived for both molecules using the planarity relations. We determined the inertial defects to be ≈ 0.05 amuÅ 2 in the ground state and ≈ -0.2 amuÅ 2 in the excited state for both furane and thiophene.
On the Parameter Plane of Nonlinear Coupled Oscillators
Authors: Metzler Wolfgang , Brelle Achim , Schmidt Klaus-Dieter , Danker Gerrit , Köppe Matthias , Mahrenholz Daniel
Published: February 2015

Two well-known bifurcation routes to chaos of two-dimensional coupled logistic maps are embedded in a two-parameter plane of a canonical nonlinear oscillator which contains a non-analytic analogon to the Mandelbrot set.
Relaxation in Perturbed Area-Preserving Maps
Authors: Breymann W.
Published: February 2015

By means of the linear response of the cat map to a constant perturbation, it is illustrated how relaxation to equilibrium occurs in chaotic hamiltonian systems.
Three Types of Chaotic Attractors in 3 D Maps
Authors: Klein Michael , Kittel Achim , Baier Gerold
Published: February 2015

Coupling a one-dimensional chaotic forcing to a stable fixed point in the plane may generate different fractal attractors embedded in three dimensions. The system with real eigenvalues of the fixed point gives rise to simple chaotic attractors with three different types of fractal structures. We show that the competition of local exponents provides a generic criterion for the classification of the fractal structures in dynamical systems.
Iterated Differentiable Maps with Nowhere Differentiable Basin Boundaries
Authors: Metzler Wolfgang
Published: February 2015

The fractal basin boundary of a two-dimensional discrete dynamical system modelling a chaotic forcing applied to bistability is shown to be identical to the graph of an infinite series F(x,t)=

of weighted iterates of an ergodic unimodal interval function f. In the special case, when f is the logistic map in "full chaos", i.e. ƒ: x ↦ 4x(1 - x), F is a nowhere differentiable function of x for each t > exp(-λf) (even equal to the Weierstrass function), where λf >0 is denoting the Lyapunov exponent of f. For further chaotic functions f, nowhere-differentiability is shown to be obvious from computer simulations.
High-Resolution Vibrational Spectra of Furazan IV. The Aj Fundamental v2 at ~ 1418 cm-1 from Fourier-Transform Infrared Spectroscopy
Authors: Stiefvater Otto L. , Klee Stefan
Published: February 2015

The band origin of the A1 mode v2 , which represents the symmetrical stretching vibration of the two C = N bonds of furazan, has been determined from the high-resolution FT-IR band as v2
0 = 1418.4724± 0.0001 cm-1. The rotational parameters of this excited state, as determined in a preceding DRM microwave study, have been confirmed and their precision was raised through the combined fit of microwave data and of some 2500 rovibrational transitions.

The use of conjugate low-J Q-branch lines for the determination of the origin of a B-type IR band of an asymmetric rotor is illustrated.
Some Monotonicity and Convexity Results for Integral Means
Authors: Laurence Peter , Lortz Dietrich , Spies Günther , Soria Fernando
Published: February 2015

Analogues and extensions of the classical result on monotonicity of Lp norms and log convexity of pth power of Lp norms are established
Rayleigh-Taylor Instability of a Compressible Plasma with Finite Larmor Radius Effects
Authors: Ariel P. D.
Published: February 2015

The Rayleigh-Taylor instability of a compressible plasma in the presence of a horizontal magnetic field is investigated, taking into account the effects of finite Larmor radius. Only transverse perturbations are considered. The problem is shown to be characterized by a variational principle. Using it, the dispersion relation is obtained for a plasma layer of finite thickness and having an exponentially varying density. It is found that the finite Larmor radius effects can thoroughly stabilize unstable configurations. For configurations which are not completely stabilized, the compressibility stabilizes some of the disturbances which are unstable for an incompressible plasma.
A Simple Deviation from Relativity
Authors: Süssmann Georg
Published: February 2015

A test of special relativity is proposed by conceiving a rather natural generalization of the minkowskian spacetime. This is mathematically similar to generalizing the notion of finite dimensional Banach space of the related Hilbert space concept. A corresponding experiment might be feasible with appropriate quantum optical methods.
Particles and Charges in the Vortex Sponge
Authors: Dmitriyev Valery P.
Published: February 2015

The vortex sponge, which postulates a steady state of vortex turbulence in an ideal fluid, is a substratum invented to explicate parsimoniously "action at a distance" and especially vacuum electromagnetics.

A disturbance of the vortex sponge's structural elements is shown to behave like a Schrödinger quantum particle. Vorticity reversal points model elementary electrical charges.
Molecular Motion in Solid Tetraethyl-and Tetrabutylammonium Perchlorates
Authors: Szafrańska Barbara , Pająk Zdzisław
Published: February 2015

The proton NMR second moment and spin-lattice relaxation time for polycrystalline tetraethyl-and tetrabutylammonium perchlorates have been measured over a wide range of temperatures. Solid-solid phase transitions related to the onset of cation tumbling were found for both compounds and confirmed by DSC. In the low temperature phases methyl-group reorientation was evidenced. For tetrabutylammonium cation a dynamic nonequivalence of one methyl group is found. The geared motion of the alkyl chains related with the onset of successive CH2-group reorientations is suggested.
The Bond N -Cl. A Spectroscopic (35Cl-NQR, IR) Investigation
Authors: Gowda B. Thimme , Weiss Alarich
Published: February 2015

Chlorine bound to nitrogen is an interesting oxidizing agent in aqueous, partial aqueous and non-aqueous media. One can assume that the oxidizing action of the chlorine depends on the polarization of the Cl atom in the bond N -Cl which will depend on the electron distribution in the ligands R and R″ of the configuration R -NCl -CO -R″. 17 compounds were synthesized with R = substituted phenyl radical C6H5-y Xy, X = Cl, NO2, R″ = CH2Cl. The 35Cl NQR frequencies are observed in the range 52 to 54 MHz (T = 77 K) for the Cl(N) 34 to 37 MHz for the phenyl chlorines and the CH2Cl group. Their temperature dependence was followed up to 300 K. Therefrom the assignment of the resonance to certain Cl-atoms in the molecules is possible. Generally, the substitution of a negative substituent X (Cl, NO2) in the phenyl ring raises the resonance frequencies; the influence of the CH2Cl group on the N -Cl bond is weak. Strong is the influence of the carbonyl group on the N -C l bond. The IR group frequencies ν(C = O) are found in the range 1680 ≤ ν (C = O)/ cm−1≤ 1717, shifted up by ≤ 20 cm−1 compared to the corresponding acetamide R ⎯ NH ⎯CO ⎯ R″. Influence of the phenyl ring substitution on ν (C = O) does not follow a simple law of inductive effect. Also a correlation between the vibration frequencies of the N ⎯ Cl group and the phenyl group substitution is not found.
Semiempirische Rechnungen zur Bestimmung der Konformation des 4,5-Dihydro-1,3-dioxepins und seines 2-Methyl-Derivats
Authors: Esser Josef , Fleischhauer Jörg , Frauenrath Herbert , Jansen Christoph , Kramer Bernd , Runsink Jan
Published: February 2015

Semiempirical Calculations for the Determination of the Conformation of 4,5-dihydro-1,3-dioxepine and its 2-methyl derivative

The possible conformations of the title compounds have been studied with the semiempirical methods MNDO and AM1. In the local minima, the vibration frequencies have been calculated to get the free enthalpy of each conformer and its equilibrium concentration. The energy minimized structures and the calculated thermodynamical values are compared with experimental results. From our investigations we conclude that the chair conformation is preferred. In the case of the methyl derivative, the substituent favours the equatorial position.
Structural Features for Non-Existence of Conjugated Patterns for Carbocyclic and Heterocyclic Compounds
Authors: Morikawa Tetsuo
Published: February 2015

At least one polygonal arc (a′ a a′), where (a′) and (a) denote unconjugated and conjugated vertices (connected with two vertices), respectively, is involved implicitly and/or explicitly in a skeleton of carbocyclic and heterocyclic compounds with no side-chains, if the number of conjugated vertices is even, and if there is no conjugated structure. This case is discussed in detail.
Delayed Feedback Control of Chaos in an Electronic Double-Scroll Oscillator
Authors: Kittel A. , Parisi J. , Pyragas K. , Richter R.
Published: February 2015

We present experimental results on stabilizing unstable periodic orbits of an autonomous chaos oscillator based on a simple electronic circuit. Control is achieved by applying the difference between the actual and a delayed output signal of the oscillator. The quality of chaos control can be measured via the strength of perturbation. The dependence on the delay time shows a characteristic resonance-type behavior.
Nonequilibrium Phase Transition and Current Filaments in Extrinsic Semiconductors
Authors: Christen Thomas
Published: February 2015

A phenomenological model for charge transport in extrinsic semiconductors is presented. For shallow impurities, large saturated impact-ionization coefficient and sufficiently low lattice temper­ature, the current-field characteristic is S-shaped (SNDC) due to the interplay between impact ionization and scattering of carriers from acoustic phonons, ionized and neutral impurities. The present model provides and explanation of the experimentally observed disappearance of SNDC above a critical lattice temperature. In the region of negative differential conductivity where a current-controlled uniform state is unstable, current filaments are calculated numerically.
Automatically Tuned Probe Head System for Pulsed NQR Spectroscopy in Extreme Thermodynamic Conditions
Authors: Ostafin Michał , Maćkowiak Mariusz , Bojarski Marek
Published: February 2015

A complete N Q R probe-head system operating in the frequency ranges 0.5 -150 and 150- 300 MHz is described. The head is particularly suited for NQR experiments carried out at a remote location, for example in a low-temperature cryostat or high-pressure chamber. Moreover, the head system includes a microprocessor-controller for automated tuning of the probe to the operating frequency of the associated NQR spectrometer. The controller can be easily interfaced to a PC via standard serial port.
Quadrupole Coupling in some H-bonded Organic Systems by ab initio Lattice Calculations of Electric Field Gradients
Authors: Palmer Michael H. , Blair-Fish John A.
Published: February 2015

We present ab initio Hartree-Fock lattice calculations performed in the unit cell environment, to compute a wave-function and the derived electric field gradients for the bulk material. These calculations differ from cluster calculations by including the effects of more distant neighbour molecules. Examples considered are ammonia, formamide, oxamide, urea, thiourea, uracil, para-banic acid, alloxan, guanidine bicarbonate and melamine.
The Nuclear Quadrupole Resonance of the 63, 65Cu Nuclei in Copper (I) Complexes
Authors: Lucken Edwin A. C.
Published: February 2015

The 63Cu NQR spectra of Cu(I) complexes are surveyed and discussed in terms of the coordination number of the copper atom , the nature of the ligands and the charge of the complex.
81Br NQR for Uncoordinated Br ions in trans-[CoBr2(en)2][H5O2]Br2 and trans-[CoBr2(en)2] [D5O2]Br2
Authors: Honda H. , Sasane A. , Miyagi K. , Ishikawa A. , Mori Y.
Published: February 2015

The temperature dependence of the 81Br NQR frequencies (vD) for uncoordinated Br- ions in trans-[CoBr2(en)2] [D5O2]Br2(D) has been determined by a continuous-wave spectrometer. vD amounted to 16.200 MHz at 273 K. This is lower by 418 kHz than the 81Br NQR frequency (vH) for trans-[CoBr2 (en2] [H5O2 ]Br2 (H). The frequency difference (Δv = vH -vD) remained almost constant in the temperature range studied. A shortening of the O-H bond length caused by deuteration could explain the magnitude and the sign of Av on the basis of a point charge model calculation. The compounds D and H yielded 81Br NQR lines in the range 110-320 K and 90-343 K, respectively. As to the 59Co NQR frequencies (7/2 - 5/2), the observed isotope frequency shifts (Δv1 = v1H - v1D) between D and H were smaller than 5 kHz. Below 160 K, 59Co resonances were only available by pulsed experiments. 59Co NQR spin-lattice relaxation times T1Q of 0.54 ms at 194 K and 4.8 s at 77 K for H have been observed.
Structural Phase Transition of N,N-Dimethylnitramine as Studied by 14N Nuclear Quadrupole Resonance
Authors: Asaji Tetsuo , Tomizawa Hideshi , Ikeda Ryuichi
Published: February 2015

The 14N nuclear quadrupole relaxation time and resonance frequencies v+, v-, and vd of N,N-dimethylnitramine were measured between 14 and 313 K. The frequency increase of v+ and v- observed below Tc (108 K) is explained by the increase of p π electrons in the amino nitrogen caused by the deformation of the molecular skelton, which is planar above Tc. The sharp T1Q minima for v+ and v- observed at Tc are attributed to the softening of vibration modes on both sides of Tc. The fluctuation o f the nitrogen-hydrogen magnetic dipolar interaction due to CH3 reorientation was detected as a broad T1Q minimum observed around 84 K. A logarithmic divergence of T1Q
-1 observed on the high-temperature side of Tc suggests the presence of a diffusive or overdamped-type soft mode.
Low Temperature Isotope Effect in Ammonium Hexachloroselenate(IV) Studied by 35Cl NQR
Authors: Kume Y. , Asaji T. , Ikeda R.
Published: February 2015

The temperature dependence o f the 35Cl NQR frequency and spin-lattice relaxation time T1Q of (NH4)2SeCl6 and (ND4)2SeCl6 were measured from 400 K to 24.8 and 53.8 K, respectively. The disappearance of NQR signals in the low temperature region of both salts is attributed to phase transitions. We concluded from the temperature behavior of just above the transition point that the operative mechanism o f the transition is different in these salts: The transition of (ND4)2SeCl6 seems to be associated with rotary soft modes, while in the natural salt non-rotary soft modes seem to play an important role at the transition.
Materials Characterisation by Nuclear Quadrupole Interaction
Authors: Bastow T.J.
Published: February 2015

The power of solid state NMR to characterise solids by determining the nuclear quadrupole coupling of the constituent nuclei is demonstrated for a number of com pounds of current interest in a materials science laboratory. Recent results are presented for the nuclei 17O , 23Na, 27Al, 39K, 71Ga, 91Zr, 93Nb, and 139La. These were derived using a variety of FT NMR techniques including static, magic angle spinning and frequency stepped spin echo NMR spectroscopy.
Why is the Cu(2) Asymmetry Parameter of NQR Spectra in HTSC so Small?
Authors: Eremin M. V.
Published: February 2015

An explanation has been proposed for the unusual behaviour of the asymmetry parameter of NQR spectra of Cu(2) in layered cuprates. When holes are introduced into the plane, Zhang-Rice singlets (ZRS) appear which have a strong vibronic coupling to tetragonal and orthorhombic modes. The equation for the adiabatic potential has been derived. It is shown that its minimum, correspond­ ing to orthorhombic distortions of the oxygen plaquette around the Cu(2) ions, changes under doping to tetragonal character due to the singlet exchange coupling between copper and oxygen holes. A strong interaction of ZRS via the phonon field has been found.
Calculated Spin-lattice Relaxation of 103Ru Compared with Low Temperature Quadrupole Orientation Measurements
Authors: Markendorf R.
Published: February 2015

The spin-lattice relaxation time T1 in 103Ru has been determined on the basis of the Dirac theory and strict relativistic band structure calculations. The low temperature relaxation time T(of 103Ru in an axially symmetric quadrupole field and the quadrupole moment Q have been measured by Green and Stone using the technique of low temperature quadrupole orientation. For the usual reference value T1 T, which corresponds to relaxation in a Zeeman spectrum, they obtain 39(6) sK, which exceeds our value by 134%. This large discrepancy is attributed to the fact that the spin relaxation by direct quadrupole scattering of conduction electrons, the so-called Mitchell contribution, is dominant. According to our calculations it amounts to 81% of the total relaxation rate. This contribution could not be included in the evaluation of the experimental data.
Quadrupole Interaction at Surfaces -Nuclear Methods
Authors: Haas H.
Published: February 2015

The measurement of the electric quadrupole interaction with nuclear techniques allows the study of monolayer coverages or even isolated atoms at surfaces and interfaces due to the inherent sensitivity of these methods. Recently electric field gradients at surface atoms have been investigated with Mößbauer Spectroscopy, Polarized Beam NMR , and Perturbed Angular Correlation (PAC).

The highly sensitive PAC technique with 111In and 111mCd sources, in particular, has been applied to several metal and semiconductor surfaces. The use of flat as well as stepped surfaces has allowed the assignment of the measured quadrupole interaction frequencies to specific surface sites. For the Pd(111) surface a particularly complete description is possible, since for five different sites (terrace adatoms, ledge adatoms, kink adatoms, ledge and terrace atoms) the field gradients and their orientation could be determined. They represent a challenging problem for understanding the electronic structure of metallic surfaces. Through the study of the temperature dependence of the different components the diffusion of the radioactive probe atoms can be followed.

The data from 57Fe Mößbauer spectroscopy on iron surfaces with monolayer coverage and NMR surface studies of 7Li and 23Na at high temperatures are reviewed.

An outlook for further developments of the nuclear techniques is presented, particularly in view of the variety of radioactive isotope beams available from on-line isotope separators like the ISOLDE facility at CERN.
Rayleigh-Taylor Instability of Newtonian and Oldroydian Viscoelastic Fluids in Porous Medium
Authors: Sharma R. C. , Bhardwaj V. K.
Published: February 2015

The Rayleigh-Taylor instability of viscous and viscoelastic (Oldroydian) fluids, separately, has been considered in porous medium. Two uniform fluids separated by a horizontal boundary and the case of exponentially varying density have been considered in both viscous and viscoelastic fluids. The effective interfacial tension succeeds in stabilizing perturbations of certain wave numbers (small wavelength perturbations) which were unstable in the absence of effective interfacial tension, for unstable configuration/stratification.
Investigation of the Zero-Field Splitting of d8 Ions in Pseudo-tetragonal Ni(II) Compounds
Authors: Chen Jia-Jun , Du Mao-Lu , Li Zhao-Ming
Published: February 2015

This paper presents a cluster approach to the zero-field splitting (ZFS) of the ground state 3A2(F) of d8 ions with tetragonal symmetry, in which not only the spin-orbit coupling of the central transition-metal-ion but also that of ligands contributes. For some pseudo-tetragonal Ni(II) com­ pounds the calculated values of the ZFS parameter follow the order Cl-> Br-> I-. This agrees with the experimental finding, while the pure crystal field approach considering only the coupling of central metal ion yields the opposite trend.
14N Quadrupole Relaxation of DMF and DMF-d7 in DMSO at Infinite Dilution
Authors: Mao Xi-an , Holz Manfred
Published: February 2015

The 14N quadrupole relaxation time in pure DMF is by 9% longer than in pure DMF-d7, showing the dependence of the reorientational molecular motion on the square root of the moment of inertia. But for traces of DMF and DMF-d7 in DMSO, the 14N quadrupole relaxation time tends to obey the "square-root-of-the-reduced-mass law", as expected from the kinetic theory of dense fluids. The vanishing of the moment-of-inertia effect on the intramolecular nuclear quadrupole relaxation is discussed in terms of molecular translation-rotation coupling.
Reanalysis of the Nuclear Quadrupole Coupling in the Rotational Spectrum of N-Methylpyrrole
Authors: Huber S. R. , Bauder A.
Published: February 2015

The rotational spectrum of N-methylpyrrole has been measured with pulsed nozzle Fourier transform microwave spectrometers between 6 and 38 GHz. The quadrupole hyperfine structure due to 14N has been reanalyzed in the A (m = 0) state o f the methyl internal rotation. Improved rotational constants, centrifugal distortion constants, and quadrupole coupling constants have been simultaneously determined from the measured transition frequencies in an iterative least-squares fit.
The Bond N-Cl. Crystal Structures and 35Cl NQR of N-Chloro-N-Phenyl-2-chloroacetamide, N-Chloro-N-phenyl-2,2-dichloroacetamide, N-Chloro-N-phenyl-2,2,2-trichloroacetamide, and N-Phenyl-2,2,2-trichloroacetamide
Authors: Dou Shi-qi , Gowda B. Thimme , Paulus Helmut , Weiss Alarich
Published: February 2015

The crystal structures of C6H5NClCOCH2Cl (1), C6H5NClCOCHCl2 (2), C6H5NClCOCCl3 (3),

and C6H5NHCOCCl3 (4) have been determined at room temperature (lattice constants, d in pm).(1): P21 /c, Z = 4, a = 738, b = 645, c = 1891, β = 90.41°, d (N -C l) = 171, d (C = O ) = 121; (2): P21 /c, Z = 4, a = 820, b = 1495, c = 905, β = 114.78°, d (N -Cl) = 171, d (C = O ) = 120; (3): P 21/c, Z = 4,

a = 819, b = 1853, c = 718, β = 103.64°, d (N -Cl) = 172, d (C = O ) = 120; (4): P21/c, Z = 4, a = 551, b = 1704, c = 1035, β = 93.08°, d (C = O) = 121.

For (2), (3), and (4) the 35Cl NQR frequencies have been determined in the range 77 ≤ T /K ≤ 300. At 77 K (γ in MHz): (2): γ(w,1) = 37.600, γ(w,2) = 38.188, γ(N) = 51.858; (3): γ(w,1) = 39.944, γ(w,2) = 40.512, γ(w,3) = 40.739, γ(N) = 52.791; (4): γ(w,1) = 39.428, γ(w,2) = 39.452, γ(w,3) = 39.986. For the compound C6H5NHCOCHCl2 (5) the 35Cl NQ R measured at 77 K is: γ(w,1) = 37.195 MHz, γ(w,2) = 37.596 MHz. The relation, γ(35Cl) = d (N -Cl) is discussed.
A Generalized Kac Model as a Dynamical System
Authors: Péntek Á . , Toroczkai Z. , Mayer D. H. , Tél T.
Published: February 2015

Ising chains characterized by smoothly varying two-body potentials, including a generalized version of the Kac model, are studied. As a novel aspect we show that one-dimensional maps associated with such chains in the spirit of the thermodynamical formalism possess fractal deriva­tives. We discuss how long-range potentials lead to intermittent-like behavior in the associated one-dimensional map.
Phase Transitions in MIITiF6 · 6H2O (M = Cd, Zn, Co): An EPR Study
Authors: Jayaram Geetha
Published: February 2015

Paramagnetic Mn2+ ions have been incorporated into CdTiF6 · 6H2O, ZnTiF6 · 6H2O and CoTiF6 · 6H2O single crystals, and EPR spectra have been utilized to investigate the structural phase transitions in these crystals. They are first order in nature with a marked hysteresis in the case of CoTiF6 · 6H2O and are attributed to hindering of rotation of the [M(H2O)6] as well as (TiF6) groups.
On the Validity of Additivity Rules for the Molecular Magnetizability Tensor and the Molecular g-Tensor in van der Waals Complexes. A Rotational Zeeman Effect Study o f 1,1-Dideutero-Cyclopropane
Authors: Böttcher O. , Meyer V. , Sutter D. H.
Published: February 2015

The molecular g-tensor and the magnetic susceptibility anisotropy of cyclopropane were deter­ mined by a microwave Fourier transform study of the rotational Zeeman effect of its 1,1-dideuterated isotopomer. The results g⊥ = 0.02675(23), g∥ = 0.06998(23), and ξ⊥ - ξ ∥ = 8.80(31) · 10-6 erg G-2 mol-2 are in agreement with values determinea indirectly from van der Waals complexes. This finding provides experimental evidence that in van der Waals molecules additivity rules might hold to a high degree of approximation for both types of tensors. Rotational Zeeman effect studies of van der Waals complexes may thus provide valuable extra information on their structures.
An Effect of Urea on Association and Solvation of Ions in Aqueous Solutions of Alcohols
Authors: Hawlicka Ewa , Lis Tomasz
Published: February 2015

The conductivity of NaI in ternary solvents consisting of water, alcohol and urea has been determined at 25 °C in its dependence on the alcohol concentration. Viscosities and static dielectric constants of these ternary solvents have also been measured. It has been found that in all studied solvents the limiting equivalent conductivities λ0 are smaller than those in binary solvents despite of the lower viscosities. The observed effect indicates that urea prevents the dehydration of ions and also hinders the ionic association. These phenomena have led to the conclusion that urea molecules are able to solvate alcohol clusters similar to what has been observed for micelles.
35Cl and 79Br NQR Spectra in Cp2M Hal2
Authors: Kuznetsov S. I. , Bryukhova E. V. , Khotsyanova T. L. , Semin G. K.
Published: February 2015

The 35Cl and 79,81Br NQR spectra of (C5H5)2M Hal2 (M = Ti, Mo, W, Zr, Hf; Hal = Cl, Br) are similar. They are quadruplets with splittings ranging from 2 to 7%. The averaged frequencies of chlorine and bromine are related by a linear dependence. The temperature dependence of 81Br in Cp2HfBr2 (in the range of 77 ≑ 224 K.) is of conventional character with frequencies slowly changing with temperature; phase transitions have not been observed.
On the Microscopic Stress Tensor for Anisotropic Molecules in Homogeneous Systems
Authors: Chrzanowska A. , Sokalski K.
Published: February 2015

The flowing nematic liquid crystal is considered in the small velocity gradient approximation. The molecular expression for the stress tensor is improved by use of the procedure of Doi. The symmetric and antisymmetric parts of the microscopic stress tensor are shown to differ by the formfactor in comparison to forms which have been used so far. The consequences for the molecular hydrodynamic theories are considered.
Isonumeric Compounds: Derivative Enumeration
Authors: Novak Igor
Published: February 2015

The basic expressions governing derivative enumeration are given and a sufficient condition proposed which applies to isonumeric compounds.
The G-Band Systematics of Vibrational and Transitional Nuclei with A = 150 to 166
Authors: El-Zaiki M. I. , Abdel-Baeth H. E.
Published: February 2015

The vibrational and rotational characteristics of the ground bands of even-even nuclei with 150 ≤ A ≤ 166 (2 < R4< 3) are studied. The spectra of these nuclei (with band crossing angular momentum IC ≥ 12) are analyzed with a cubic polynomial in I. The considered nuclei (150Sm, 152Gd, 154-156Dy, 156Er, 158-160-162Yb and 162,164, 166Hf) lie in the central region between the Z = 50 and Z = 82 major shell closures and span the spherical to the well deformed region. The gradual shape transition from a soft spherical vibrator to a deformed rotor from 150Sm to 166Hf is thus made explicitly apparent from the g-band spectrum analysis in terms of the vibrational, rotational and softness coefficients.

The transition at N = 88-90 for the vibrational-rotational ratios and for the kinematic moments of inertia are reproduced.
X-Ray Diffraction Study on the Local Structure of Molten ErCl3
Authors: Iwadate Yasuhiko , Iida Takuma , Fukushima Kazuko , Mochinaga Junichi , Gaune-Escard Marcelle
Published: February 2015

The short range structure of molten ErCl3 at 1053 K was investigated by X-ray diffraction. The nearest neighbour distance of Er3+-Cl- and the coordination number of Cl- around Er3+ were estimated to be 2.63 Å and 5.8 Å, respectively, and the Er3+-Er3+ and Cl--Cl- distances 4.05 Å and 3.75 Å, respectively. The ratio of the anion-anion pair distance to the cation-anion pair distance (r--/r+-) was, therefore, 1.43, being close to 1.41, characteristic of octahedral geometry. These results indicate that ErCl6
3--octahedra exist in molten ErCl3. Probably Er2Clio and a small amount of Er2Cl11
5- ions are formed according to the geometrical calculations of bond lengths and bond angles.
The Dependence of Vicinal Proton-Proton Coupling Constants on Molecular Structure
Authors: Marković Zoran , Konstantinović Stanimir , Gutman Ivan
Published: February 2015

A modification of the Karplus equation is put forward, containing for mutually independent structural terms and four adjustable parameters. Among the new factors introduced in this modifi­cation are the distance between protons and Muallay's group electronegativity, used in the evalua­tion of the α-substituent effect. The new equation reproduces experimental NMR vicinal coupling constants with a standard deviation of about 0.6 Hz.
Notiz: A very Simple Mass Formula for the Masses of Pseudoscalar Mesons
Authors: Otte Hubert
Published: February 2015

The masses of pseudoscalar mesons are approximately proportional to quadratic powers of integers.
Reflection of Cluster Beams on Metal Surfaces: Momentum and Heat Transfer
Authors: Mayer H.
Published: February 2015

Beams of clusters, the latter containing about 106 nitrogen molecules, were reflected by polished metal surfaces, and the direction, the velocity and the composition of the reflected beams were studied as functions of the direction of the incident beam. It turned out that the clusters leave the reflector surface almost tangentially, with reduced velocity, and that besides the clusters the beams contain gaseous nitrogen formed during the impact.
FT-IR Study of the Perpendicular Bands of 1,3,5-Triazine I:* The v7 and v9 Bands of 12C3
14N3H3 , 13C3
14N3H3, 12C3
15N3H3 and the Difference Band v9-v14 of 12C3
14N3H3
Authors: Pfeffer M. , Bodenmüller W. , Ruoff A.
Published: February 2015

The analysis of the high resolution FT-IR spectra of the perpendicular bands v7 (E') at about 1550 cm -1 and V9 (E') at about 1170 cm -1 of the isotopomers 12C3
14N3H3 , 13C3 14N3H3 , and l2C3
I5N3H3 is given. Both bands proved to be free from accidental resonances. The molecular constants of the state v7 = 1 and v9 = 1 of the isotopomers under consideration are listed. The weak difference band v9-vl4 (E" → E') of 12C3
14N3H3 was recorded and analyzed, using the molecular constants of v9 = 1 [this work] and V14 = 1 [of 1995], This analysis proves the quality of the molecular constants of the fundamental v14 which is IR-inactive.
Dielectric Behaviour of Some Pure Normal Alcohols and their Binary Mixtures
Authors: Eid M. A. M. , Hakim I. K. , Abd-El-Nour K. N. , Saad A. L. G. , Stockhausen M.
Published: February 2015

The pure 1-alkanols C4 to C12 and seven of their short/long chain binary equimolar mixtures are in-vestigated by static and dynamic dielectric measurements up to 36 GHz at 20, 30 and 40 °C. The apparent dipole moment and the relaxation parameters from a three Debye term analysis of the spectra are discussed. The mixtures are found to behave like a one component alcohol of mean chain length. An odd-even effect is revealed by comparison of mixtures containing C11 with those containing C12 as long chain mixture component.
An Investigation of the Structure of Amorphous Co-P Alloys. 1: X-ray and Neutron Diffraction
Authors: Nuding Mi. , Lamparter P. , Steeb S.
Published: February 2015

Amorphous Co-P alloys with different phosphorous concentrations were produced by meltspinning, sputtering, and electrodeposition. From the combination of X-ray and neutron diffraction the atomic distances and coordination numbers for the Co-Co- and the Co-P correlations were determined. The short range structure, in dependence of the P-concentration, 9 at% P ≤ cp ≤ 26 at% P, exhibits rather abrupt changes at the eutectic composition, cpe = 19.9 at% P. It is suggested that at P-contents above cp,e the short range order is more pronounced than at lower P-contents. The coordination of nine Co atoms around P, as established previously for many transition metal-metalloid glasses, is found only at the eutectic composition. There is almost no dependence of the structure of the amorphous alloys on the specific production method. It is indicated that the melt-spun and the sputtered glasses are in a slightly more relaxed state than the electrodeposited glasses.
Applications of Nuclear Quadrupole Interactions in Materials Research
Authors: Shengyun Zhu
Published: February 2015

The principle of the time differential perturbed angular correlation and distribution technique which measures the nuclear quadrupole interaction is briefly described. Some examples are given to show the possibilities of this technique in microscopic studies of materials.
Electric Quadrupole Interaction at 181Ta in Isostructural Orthorhombic Cu8Hf3 and Cu8Zr3 Compounds
Authors: Wodniecki P. , Wodniecka B. , Kulińska A. , Hrynkiewicz A. Z.
Published: February 2015

The quadrupole interaction of 181Ta probes in isostructural Cu8Hf3 and Cu8Zr3 intermetallic compounds was studied in the temperature range 24 K -1100 K with the time-differential perturbed angular correlation technique. Two nonaxial electric field gradients corresponding to two nonequiv-alent hafnium or zirconium sites in the investigated structure were found. A linear decrease in the quadrupole interaction frequency with increase of temperature for the 8(d) sites was evidenced, while the vQ(T) dependence for the 4(c) sites is weaker and has a T3/2 character.
NMR · NQR and DTA · DSC Studies of Phase Transitions in Pyridinium Tetrachloropalladate(II) and Pyridinium Tetrachloroplatinate(II)
Authors: Asaji Tetsuo , Horiuchi Keizo , Chiba Takehiko , Shimizu Takashige , Ikeda Ryuichi
Published: February 2015

From the measurements of DTA • DSC and the temperature dependences of 35Cl NQR frequencies, phase transitions were detected at 150 K, 168 K, and 172 K for (pyH)2 [PtCl4], and at 241 K for (PyH)2 [PdCl4]. In order to elucidate the motional state of the constituent ions in the crystals in connection with the structural phase transitions, the 35Cl NQR and 1H NMR spin-lattice relaxation times and the second moment of the 1H NMR line were measured as functions of temperature. For both compounds, the potential wells for the cationic reorientation are suggested to be highly nonequivalent at low temperatures. Above 168 K, the pyridinium ions in (pyH)2[PtCl4] are expected to reorient between almost equivalent potential wells. As for (pyH)2[PdCl4], it is expected that the orientational order of the cation still remains even above the second order transition at 241 K. A change of the potential curve from two-unequal to three-unequal wells is proposed as a possible mechanism of the second order transition. The activation energies for the cationic motion in the respective model potential are derived for both compounds at high and low temperatures.
Studies of Successive Phase Transitions and Molecular Motions in [Mg(H2O)6][SiF6] by 1,2H and 19F NMR
Authors: Kimura Junko , Fukase Takeshi , Mizuno Motohiro , Suhara Masahiko
Published: February 2015

The successive phase transitions of [Mg(H2O)6][SiF6] were studied by measuring 2H NMR spectra. The quadrupole coupling constant e2Qq/h and asymmetry parameter η changed drastically at each transition temperature. 1,2H and 19F NMR Tl were measured for this compound to study the relation between the molecular motions and the successive phase transitions. The activation energy Ea and the pre-exponential factor τ0 for the reorientation of [SiF6]2- were estimated as 28 kJmol-1 and 6.0 x 10-14 s, and those of the 180° flip of H2O as 33 kJmol-1 and 4.0x 10-14 s. These two motions occur rapidly even in phase V. For the reorientation of [Mg(H2O)6]2+ , Ea = 62 kJmol-1 and τ0 = 1.1 x 10-16 s were obtained from the simulation of 2H NMR spectra. The jump rate of this motion is of the order of 104 -106 s-1 in phase II. These results suggest that the successive phase transitions are closely related to the motion of [Mg(H2O)6]2+ .
FT-NMR Detection of 45Sc, 49Ti and 93Nb in TiO2 Single Crystal
Authors: Sato K. , Takeda S. , Fukuda S. , Minamisono T. , Tanigaki M. , Miyake T. , Maruyama Y. , Matsuta K. , Fukuda M. , Nojiri Y.
Published: February 2015

In order to determine the electric quadrupole moment of the short-lived β-emitter 41Sc from the quadrupole coupling constant in TiO2 , we measured the field gradient by detecting the Fourier-Transformed-NMR of stable isotope 45Sc doped in TiO2. Also, in order to study the electronic structure of impurities systematically, EFGs were measured for 45Sc, 49Ti and 93Nb in a TiO2 ingle single crystal.
23Na NMR and 14N NQR in Mixed Crystals Na1-xAgxNO2
Authors: Jung J. K. , Seo Y. M. , Choh S. H.
Published: February 2015

The 23Na (I = 3/2) NMR powder pattern for the m = 1/2 ↔ m = -1/2 transition, broadened by the second-order quadrupole interaction, was investigated in mixed crystals Na1-xAgxNO2 (x<̱0.16). From the intensity loss of the 23Na NMR line caused by the Ag+ -impurity, the range of the quadrupole interaction in the 23Na NMR central line was estimated. The range comprises ionic charges approximately up to the first nearest neighbour Na+ site from the 23Na nucleus, showing a large difference compared with that obtained from the 14N NQR investigation in the same system.
The Features of Mössbauer Spectra of Hemoglobin in Relation to the Quadrupole Splitting and Heme Iron Stereochemistry
Authors: Oshtrakh M. I.
Published: February 2015

Mössbauer spectra of various human ferrous hemoglobins in different ligand forms demonstrated some features such as non-Lorentzian line shape for oxyhemoglobins, narrower line width for carbonmonoxide, and variations of quadrupole splitting for different hemoglobins. These features were considered in relation to the variations of quadrupole splitting and heme iron stereochemistry in different hemoglobins as well as in non-equivalent subunits of hemoglobin tetramer.
Das System P4S3–P4Se3 / The P4S3-P4Se3 System
Authors: Blachnik Roger , Wickel Ulrike
Published: February 2015

The system P4S3-P4Se3 was investigated by room temperature and high temperature X-ray techniques, MS- and 31P NMR spectroscopy and differential scanning calorimetry. At room temperature the phase diagram contains three regions of solid solubility, one from P4S3 to ca. 45 mole% P4Se3 with the a-P4S3 structure, the second from ca. 48 to 60 mole% P4Se3 of unknown structure, and the third from ca. 65 mole% P4Se3 to P4Se3 with the β-P4Se3 structure. On heating all these phases transform into a plastic-crystalline modification (ß) with complete solid solubility between P4S3 and P4Se3. For β-P4S3 d-values are determined with Cr-Kɑ1-radiation. At higher temperatures the ß-phase transforms into a γ-phase, which was characterized by high-temperature X-ray methods.

Mass and 31P NMR spectra reveal a multicomponent system consisting of all possible molecules of the type P4SχSe3-χ (χ = 0-3). All samples prepared from the melt are composed of a mixture of all these cage molecules.

For P4S3 a new modification is found by the DSC measurements. It can be shown that the enthalpy of melting consists of the ß-γ transition enthalpy and the real enthalpy of fusion. Metastable γ-P4S3 can be obtained over a broad temperature region (ca. 440-405 K) on cooling of the melt; it is probably isostructural with γ-P4Se3. For the a-ß and ß-γ transitions several kinds of hysteresis effects are described
Austauschreaktionen von Tri-n -butylethinylstannan mit Zinntetrachlorid und Zinntetrabromid - Anwendung der 119Sn-NMR Spektroskopie / Exchange Reactions between Tri-n-butyl Ethynyl Stannane and Tintetrachloride and Tintetrabromide - Application of 119Sn NMR Spectroscopy
Authors: Wrackmeyer Bernd
Published: February 2015

The formation of ethynyl stannanes XnSn(C ≡ C-H)4-n (X = Cl, Br; n - 0-3) via exchange reactions between tri-n-butvl ethynyl stannane and SnX4 is readily monitored by 119Sn NMR spectroscopy. Advantages of 119Sn NMR as compared with 1H or 13C NMR are discussed. The 119Sn and 13C NMR parameters (δ119Sn, δ13C, 1,2J (119Sn13C), 1,2J (13C1H) ) for these reaction mixtures are reported. Tri-n-butyl ethynyl stannane and bis(tri-n-butylstannyl) ethyne are both obtained from the reaction of tri-n-butylstannylchloride with Li2C2 in hexane in the presence of excess ethyne
π-Olefin-Iridium-Komplexe, IX [1] Bis(η4-butadien)-σ-organyl-iridium-Verbindungen / π-Olefin Iridium Complexes, IX [1] Bis(η4-butadiene)-cr-organyl-iridium Compounds
Authors: Müller Jörn , Hähnlein Wolfgang , Passon Barbara
Published: February 2015

Complexes of the type [L2IrR] (L = butadiene, isoprene, piperylene, 1,4- and 2,3- dimethylbutadiene; R = CH3, C6H5) have been synthesized by reactions of [L2IrCl] with LiR in hexane. With L = 2,3-dimethylbutadiene, [L2IrR] compounds with higher alkyl groups R (e.g. η-C3H7, η-C4H9) can be obtained which for steric reasons are inert against β-elimination. The system [L2IrCl]/L/LiAlH4 (L = 2,3-dimethylbutadiene) yields [L2IrR] with R = 2,3-dimethylbutene-2-yl. The complexes were characterized by NMR and mass spectra
Sekundäre Aminodiphosphane - Synthese, Konfiguration und Eigenschaften / Secondary Aminodiphosphanes - Synthesis, Configuration and Properties
Authors: Niecke Edgar , Rüger Reinhold
Published: February 2015

Both stereoisomers of 1-chloro-1,2-bis[bis(trimethylsilyl)-amino]diphosphane (4) are available by reaction of bis(trimethylsilyl)amino-dichlorophosphane with LiAlH4. Cl/Hexchange of (4) with LiAlH4 leads to the meso and racemic form of tetrakis(trimethylsilyl)- diaminodiphosphane (5).

Dynamic NMR data of the compounds 4 and 5 are discussed with respect to the molecular configurations and conformations. Equilibrium data for 5 indicate a gauche effect of about 3.8 kJ/mol