Richtlinien für die Präsentation der Methoden bei der Publikation von Rechenergebnissen – Teil A: Ab‐initio‐Berechnung der elektronischen Struktur von Molekülen

Die Übersetzung basiert auf den „Guidelines for Presentation of Methodological Choices in the Publication of Computational Results. B. Semiempirical Electronic Structure Calculations“ des Subcommittee on Theoretical Chemistry der Commission on Molecular Structure and Spectroscopy der Physical Chemistry Division der International Union of Pure and Applied Chemistry, veröffentlicht in Pure Appl. Chem. 2000 , 72, 1149–1452. Das Original wurde von James J. P. Stewart (Stewart Computational Chemistry, Colorado Springs, USA) für die Veröffentlichung vorbereitet.     

Über die Kristallstruktur von In3Mo11O17 sowie über physikalische Eigenschaften oligomerer Oxomolybdate

On the Crystal Structure of In₃Mo₁₁O₁₇ and the Physical Properties of Oligomeric Oxomolybdates In₃Mo₁₁O₁₇ is characterized by its molybdate framework Mo₂₂O₃₄^8? belonging to the general series Mo_4n+2O_6n+4^x? (with n = 5). The phase grows in star-like aggregates and crystallizes within the orthorhombic system (a = 988.0(2) pm, b = 951.2(2) pm, c = 3 176.7(4) pm). There are oligomeric clusters built from five trans edge-sharing Mo₆ octahedra, surrounded by O atoms over all empty edges according to the Aufbau principle Mo₂₂OOO. In the remaining structural channel one finds an In₆⁸⁺ polycation which is geometrically equivalent with the one of In₁₁Mo₄₀O₆₂. The Mo—O and Mo—Mo distances within the cluster are the same like in In₁₁Mo₄₀O₆₂, too, but there are shorter inter cluster distances (306 pm) in In₃Mo₁₁O₁₇. Disorder in the structure may be understood in terms of the presence of constitutional isomers. While the electrical resistivity of PbMo₅O₈ resembles the one of a strongly disturbed metal (with a local minimum around 120 K), the temperature characteristic of Tl_0.8Sn_0.6Mo₇O₁₁ is typical for a semiconductor. Oxomolybdates with even longer oligomers like In₁₁Mo₄₀O₆₂ and In₃Mo₁₁O₁₇ show metallic conductivity. This course corresponds with the sizes of the clusters and their electronic intercoupling which can be estimated from the specific lengths of the inter cluster distances. The effective magnetic moment grows with increasing cluster length from 0.97 μ_B (PbMo₅O₈) to 1.40 μ_B (In₁₁Mo₄₀O₆₂) per cluster (exception: In₃Mo₁₁O₁₂), and so does the contribution of the temperature-independent paramagnetism (from 890 to 2191 × 10^?6$ \frac{{{\rm emu}}}{{{\rm mol}}} $ per cluster). Thus, a single condensed octahedron carries roughly 440 × 10^?6$ \frac{{{\rm emu}}}{{{\rm mol}}} $ as a temperature-independent paramagnetism, similar to the M₆X₁₇ halide clusters. In₁₁Mo₄₀O₆₂ shows an interesting change in the temperature dependence of its magnetic suszeptibility.     

Notiz über die Kernresonanzspektren von trifluormethyl-substituierten Naphthalinderivaten

The proton and fluorine NMR. spectra of 25 trifluoromethyl substituted naphthalene derivatives have been analysed. The proton chemical shifts of the trifluoromethyl naphthylamines and naphthols have been correlated with calculated π-electron charge densities (PPP SCF).