The correlated ground state of diamond

The many-electron ground state wave function and energy of diamond are calculated. Thereby electron correlations are properly taken into account. This is achieved by applying a recently developed local approach to their computation. The results for the inter- and intra-atomic correlation energies are compared with those for CH₄ and the carbon atom.     

Bestimmung der Wertigkeit von Anionen durch die Isotypie ihrer Tetraphenylarsoniumsalze

Zusammenfassung Auf Grund der Isotypiebeziehungen vieler Tetraphenylarsoniumsalze lassen sich aus Röntgenbeugungsdiagrammen Wertigkeit und Größe von Anionen einfach und schnell bestimmen.

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Determination of the valency of anions by means of the isotypism of their tetraphenylarsonium salts

Based on the isotopy relations of many tetraphenylarsonium salts valency and size of anions can be determined simply and rapidly from x-ray diffraction diagrams.

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Den Herren Prof. Boek und Gattow danken wir für ihre Hilfe. Die Deutsche Forschungsgemeinschaft förderte die Arbeit durch ein Habilitandenstipendium.     

Über Chalkogenolate. 104. Untersuchungen über Halbester der Monothiokohlensäure. 3. Kristallstruktur von Kaliummethyloxoxanthat

On Chalcogenolates. 104. Studies on Hemiesters of Monothiocarbonic Acid. 3. Crystal Structure of Potassium Methyl Oxoxanthate K[SOC? OCH₃] crystallizes with Z = 4 in the monoclinic space group P2₁/n with cell dimensions a = 6.742(5), b = 6.968(5), c = 10.777(6) Å, β = 104.6(6)°. The structure has been determined from single crystal X-ray data by means of Patterson and Fourier synthesis and refined to a final conventional R value of 0.037 using 1292 independent reflexions. The structure is built up of K⁺ and [SOC? OCH₃]^? ions. The potassium ion is bonded to four oxygen and four sulfur atoms from five oxoxanthate ions. The coordination polyhedron consists of two reciprocally penetrated and distorted O₄ and S₄ tetrahedra.     

Diels-alder reactions with 2-(Arylsulfinyl)-1,4-benzoquinones: effect of aryl substitution on reactivity, chemoselectivity, and pi-facial diastereoselectivity

Diels-Alder reactions of (SS)-2-(2'-methoxynaphthylsulfinyl)-1, 4-benzoquinone (1b), 2-(p-methoxyphenylsulfinyl)-1,4-benzoquinone (1c), and 2-(p-nitrophenylsulfinyl)-1,4-benzoquinone (1d) with cyclopentadiene are reported. These cycloadditions allowed the highly chemo- and stereoselective formation of both diastereoisomeric endo-adducts resulting from reaction on the unsubstituted double bond C(5)-C(6) of quinones working under thermal and Eu(fod)(3)- or BF(3).OEt(2)-catalyzed conditions. The synthesis of endo-adduct [4aS,5S,8R,8aR,SS]-9d resulting from cycloaddition on the substituted C(2)-C(3) double bond was achieved in a chemo- and diastereoselective way from quinone 1d in the presence of ZnBr(2). The reactivity and selectivity of the process proved to be dependent on the electron density of the arylsulfinyl group.     

Über Chalkogenolate. 118. Kristall- und Molekülstruktur von Oxovanadin(V)-ethylxanthat

On Chalcogenolates. 118. Crystal and Molecular Structure of Oxovanadium(V) Ethylxanthate VO[S₂C? OC₂H₅]₃ crystallizes with Z = 8 in the monoclinic space group P2₁/n with cell dimensions a = 15.065(7) Å, b = 18.540(48) Å, c = 12.824(7) Å, = 99.31(7)°. The crystal and molecular structure has been determined from single crystal X-ray data at 20°C and refined to a conventional R of 0.045.     

Über Chalkogenolate. 191. Ester der 2-Oxophenyldithioessigsäure 2. Kristall- und Molekülstruktur des Methylesters

On Chalcogenolates. 191. Esters of 2-Oxophenyldithioacetic Acid. 2. Crystal and Molecular Structure of the Methyl Ester The title compound C₆H₅? CO? CS? SCH₃ crystallizes with Z = 2 in the triclinic space group P1 with cell dimensions (?60°C) a = 6.236(4) Å, b = 7.972(2) Å, c = 9.589(4) Å, α = 88.42(3)°, β = 75.39(5)°, γ = 81.54(4)°. The structure has been determined from single crystal X-ray data measured at ?60°C and refined to R = 0.085 and R_w = 0.087 for 2307 independent reflections. With nearly 20° the C?O bond is turned out of the plane of the phenyl ring.     

Kristall- und Molekülstruktur von Tetra-n-butylammonium-N-methyl-N-thioformyldithiocarbamat

Crystal and Molecular Structure of Tetra-n-butylammonium N-Methyl-N-Thioformyl Dithiocarbamate [N(n-C₄H₉)₄][S₂C? N(CH₃)? CS? H] crystallizes in the triclinic space group P1 (Z = 2) with cell dimensions (?45°C) a = 9.185(2) Å, b = 10.263(3) Å, c = 13.301(3) Å, α = 101.73(2)°, ß = 99.59(2)°, γ 100.57(2)°. The crystal structure was solved by means of direct methods and refined to a conventional reliability index R = 0.066 (R_ω = 0.070). 5945 independent intensities being measured.