The photoelectron spectra of D2d and C2ν hydrocarbons containing two norbornadiene or quadricylane groups

The photoelectron spectra of the hydrocarbons 1 to 4 have been recorded and interpreted by qualitative correlation with the spectra of their subsystems norbornadiene, quadricyclane, allene and cyclopropane. It has been shown that the interactions of the symmetry adapted orbitals of the subsystems are governed not only by their symmetry behaviour with respect to D_2d in 1 and 2 , or C_2ν in 3 and 4 , but also by the local symmetry at the points of attachment of the subsystems.     

Zweij?hrige Erfahrung in der Routineanalyse mit einem C-N-H-Automaten

Zusammenfassung Unsere Erfahrungen bei der Routineanalyse von festen und flüssigen Verbindungen, die z.B. D, F, Cl, Br, J, S, Se, Cr, W, P, Bi, Si, Sn, Pb, Ti, B, Hg, Na, K, Cu, Ag, Au, Fe oder Ni enthalten, mit einem Automaten, der in einem. 10 min-Cyclus die Prozentgehalte von C, N und H. ausdruckt, werden mitgeteilt.

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Summary This paper communicates our experiences in routine analyses of solid and liquid compounds, containing elements such as D, F, Cl, Br, J, S, Se, Cr, W, P, Bi, Si, Sn, Pb, Ti, B, Hg, Na, K, Cu, Ag, Au, Fe or Ni with an automatic instrument which prints out the percentages of C, N and H within 10 minutes.

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Die angegebenen Werte stellen den Standardfehler dar.     

The 18-electron electrocyclisation of vinylogous fidecene. an unusual sequence of pericyclic processes

Upon thermal activation the vinylogous fidecene $\text{1}$ is isomerised into the pentacyclic indenoid hydrocarbon $\text{13}$ (benzene, t_{$\text{1}\text{2}$} (150°C) ca. 5 min), the formation of which is explained by an initial conrotatory (“symmetry-forbidden”) 18-electron electrocyclisation followed by two fast hydrogen migrations ([1.9], [1.5]) and 14π-electrocyclisation.     

INDICATION OF FAST TRIPLET FORMATION IN BIMOLECULAR QUENCHING OF EXCITED SINGLET STATES STUDIED BY CONVENTIONAL FLASH PHOTOLYSIS

The bimolecular quenching of the first excited singlet state of oxonine by allylthiourea leads to the formation of the triplet state of the dye. This has been proved by comparison with the triplet-triplet absorption spectrum of oxonine obtained by triplet-triplet energy transfer. The conventional flash experiments suggest that the dye triplet state is produced directly rather than by radical recombination.     

Die Kristallstruktur der Verbindung Li3Zn0,5GeO4

The crystal structure of the compound Li₃Zn_0.5GeO₄ has been determined and refined by means of three-dimensionalFourier syntheses and least squares. Li₃Zn_0.5GeO₄ crystallizes orthorhombic with space groupD _2h ¹⁶ -Pmnb (No. 62) and the lattice parametersa=6.29,b=10.74 andc=5.17 Å. The crystal structure consists of isolated [GeO₄] tetrahedra, which are linked together by [(Li,Zn)O₄] tetrahedra analogous to Li₃PO₄(h). An additional eight-fold position is partly occupied by two lithium atoms. The occupancy of this position may vary according to the observed range of composition, which lies between Li_3.8Zn_0.1GeO₄ and Li_2.6Zn_0.7GeO₄.

     

Photoelectron Spectra of Unsaturated Oxides. I. 1,4-Dioxin and related systems

The He (Iα) photoelectron spectra of the four unsaturated oxides 3,4-dihydropyran ( 6 ), γ-pyran ( 7 ), 2, 3-dihydro-1, 4-dioxin ( 9 ) and 1, 4-dioxin ( 10 ) are reported and analysed. Band assignments are based on ab-initio calculations, using the STO-3G basis set. The proposed orbital sequences (with reference to the coordinate systems given in Table 1) are, for the top three orbitals: 6 , π, nσ, nπ; 7 , 3b₁(π), 1a₂(π), 11a₁(σ); 9 , 11b(π), 12a(σ), 11a(π); 10 , 2b_3u(π), 1b_1g(π), 6a_g(σ). Finally the (almost) localized π-orbitals have been computed by the Foster-Boys localization procedure.     

Cardanolides from the Chinese toad venom Ch'an Su

From the toad venom Ch'an Su the cardenolides I, III and V have been isolated. It is the first time that cardenolides and bufadienolides are detected simultaneously in a biological material.     

Die Kristallstruktur eines neuen Alkalidigermanats,Na4K2Ge2O7

Na₄K₂Ge₂O₇ is monoclinic, space group P 2₁ (No. 4),a=6.010 (3),b=6.020 (3),c=29.26 (1) Å, γ=119.9 (1)° andZ=4. Its crystal structure has been determined from 1210 single crystal X-ray reflections and refined toR=0.114. The structure contains two independent Ge₂O₇ groups, the (GeOGe) angles of which are 128 and 132°.     

Controlled immobilization of membrane proteins to surfaces for fourier transform infrared investigations

We show that it is possible to immobilize membrane proteins uniformly and reversibly as self-assembled (sub)monolayers on nitrilotriacetic acid-covered sensor surfaces via hexahistidine sequences present either in the protein or in lipid membranes. Fourier transform infrared spectra of such self-assembled (sub)monolayers deliver important structural information of the membrane proteins and are suited to screen the function of cellular receptors.     

Existence of Mott-Schwinger interaction by means of\vec p - 12C elastic scattering

The aim of this work was the unambiguous proof of the existence of the Mott-Schwinger interaction. The analyzing power of the \(\vec p - \) ¹²C elastic scattering was measured in the energy range from 450 to 600 keV for scattering anglesθ _Lab=90° and 120° with an overall accuracy up toΔA=1·10^?4. The data can be described very well with theR-matrix formalism including Mott-Schwinger interaction. Omitting this interaction large discrepancies occur.