Mean amplitudes of vibration of the ClF6, BrF6 and IF6 anions

Mean amplitudes of vibration for the title hexafluoroanions were calculated on the basis of its vibrational-spectroscopic and structural data in the temperature range between 0 and 1000 K. The results are briefly discussed in comparison with those of other related species.     

Darstellung,kristallographische Daten und IR-Spektrum von Mangan(II)-diarsenat

Mn₂As₂O₇ has been obtained by solid state reaction between As₂O₅ and MnCO₃ at 600 °C and also by thermal decomposition of NH₄MnAsO₄·H₂O. The crystallographic study has shown that the substance crystallizes in the monoclinic thortveitite structure. Its i.r. spectrum was recorded and discussed in relation with their structural properties. The i.r. spectrum of the parent compound NH₄MnAsO₄·H₂O was also briefly discussed.

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Synthesis and conformational stabilities of 11-oxo-9α- and 9β-estradiol 3-benzyl ether

11-Oxo-estradiol was prepared from estradiol in five steps with an overall yield of 50%. From an equilibration study, the 9β epimer was found to be favored over the 9α by 1.47 kcal/mole. Force field calculations were carried out for these epimers out and compared with the experimental data.     

On phases and length of curves in a cyclic quantum evolution

The concept of a curve traced by a state vector in the Hilbert space is introduced into the general context of quantum evolutions and its length defined. Three important curves are identified and their relation to the dynamical phase, the geometric phase and the total phase are studied. These phases are reformulated in terms of the dynamical curve, the geometric curve and the natural curve. For any arbitrary cyclic evolution of a quantum system, it is shown that the dynamical phase, the geometric phase and their sums and/or differences can be expressed as the integral of the contracted length of some suitably-defined curves. With this, the phases of the quantum mechanical wave function attain new meaning. Also, new inequalities concerning the phases are presented.     

Mittlere Schwingungsamplituden von ReOF4 und ReOF5

Mean amplitudes of vibration for ReOF₄ and ReOF₅ have been calculated from spectroscopic data in the temperature range between 0 and 1,000 K. The results are briefly discussed, some comparisons are made with structurally related species and certain aspects of the bond properties are analyzed.     

First principles investigation of19F* nuclear quadrupole interaction in fourth group tetrafluorides

Using the Hartree-Fock-Roothaan procedure the nuclear quadrupole interactions of the¹⁹F (spin 5/2) nucleus in CF₄, SiF₄ and GeF₄ are studied. The theoretical results explain within 10% the observed experimental measurements by the time-differential perturbed angular distribution technique, including the important feature of sharp decrease of the¹⁹F^* nuclear quadrupole coupling constant in going from CF₄ to SiF₄, followed by an increase in going to GeF₄, while a simple consideration of the ionic characters of the C-F, Si-F and Ge-F bonds together with Townes and Dailey theory would lead to a continuous decrease from CF₄ to GeF₄. The dependence of the results on the choice of basis sets and the role of many-body effects is discussed.     

Fourth-order contributions to μμ elastic scattering in the gauge theory of weak interactions

The fourth-order contributions of WW, Z? and ZZ intermediate states to the S-matrix elements of μμ elastic scattering have been calculated by dispersion theoretic techniques in the U-gauge. It is shown that the contributions are finite and very small compared to the low-order contributions. It is also shown that the main part of these finite contributions comes from the WW intermediate state.     

Growth and characterisation of new non linear optical material α-glycine sulpho-nitrate (GLSN) with stable dielectric and light dependent properties

Well defined transparent single crystals of α-glycine-sulpho-nitrate (GLSN) were obtained by slow evaporation of the solvent at room temperature. The new GLSN system crystallises in to orthorhombic symmetry with an indicative change in cell parameters depending upon the composition. CHNS, EDAX and proton NMR and carbon NMR analysis confirm the chemical units in the crystal. Comparative analysis of FTIR and laser Raman Spectra confirm the functional groups in the molecule. The TGA and DTA studies show presence of a transition anomaly at 413 K supported by resistivity and dielectric measurements. UV studies indicate wide transparency window with SWG conversion efficiency of 0.029 times of that of KDP material suggesting its use in optoelectronic devices. The crystal acts as a light sensor and exhibits light dependent nature indicative of conduction due of hydrogen ions with formation of space charge. The GSN crystal acts as a stable dielectric with a safe operating range of 300 volts/cm.