In: Chemistry - A European Journal, 2004, vol. 10(19), p. 4839-4845
Der hexadentate und ditopische Ligand 2,5-Bis([2,2']bipyridin-6-yl)pyrazin bildet bei der Selbstorganisationsreaktion mit Fe²⁺-Ionen einen chiralen, quadratförmigen Tetramerkomplex. Das Racemat dieses Komplexes wurde mit Hilfe von Antimonyltartrat in die Enantiomere getrennt. Die Reinheit des Enantiomers wurde durch NMR-Spektroskopie unter Zuhilfenahme eines chiralen, diamagnetischen...
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In: Inorganica Chimica Acta, 2005, vol. 358(1), p. 41-49
A series of ligands, where two pinene-bipyridine moieties are either connected directly, or through a p-xylene bridge are investigated with respect to their complexation behaviour in solution. The bridged [5,6]-CHIRAGEN[p-xyl] ligands, which are substituted in 5' or 6' positions show self-assembly reactions, which lead to similar supramolecular species as the unsubstituted bis-pinene-bipyridines...
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In: Helvetica Chimica Acta, 2004, vol. 87, p. 2245-2265
A short stereospecific synthesis of the carbocyclic 2'-deoxynucleoside analogues 36 and 37 (Schemes 2 and 5) and 45 and 46 (Schemes 2 and 6) starting from optically active 8,9,10-trinorborn-5-en-2-one (1) is described. As two functional groups capable to react with each other are present in the same molecule of the synthetic carbanucleosides, the latter can form polymers similar to...
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In: Chemistry - A European Journal, 2005, vol. 11(4), p. 1294-1304
Radical cations were generated from different phenyl-substituted aziridines by pulse radiolysis in aqueous solution containing TlOH.+, N₃. or SO₄.- as oxidants or in n-butyl chloride, by ⁶⁰Co γ radiolysis in Freon matrices at 77 K, and in some cases by flash photolysis in aqueous solution. Depending on the substitution pattern of the aziridines, two...
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In: Chemical Physics Letters, 2003, vol. 370(1-2), p. 99-105
A derivative version of the well-known direct inversion in the iterative subspace (DIIS) algorithm is presented. The method is used to solve the coupled perturbed Hartree–Fock (CPHF) equation to obtain the first and second derivatives of the density matrix with respect to an external electric field which, in this case, leads to the electric molecular polarizability and hyperpolarizability. Some...
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In: International Journal of Quantum Chemistry, 2003, vol. 91, no. 3, p. 297-302
In this article, we propose a theoretical study of static and dynamic polarizability α, first hyperpolarizability β, and second hyperpolarizability γ of substituted (M)-tetrathia-[7]-helicenes. Both a semiempirical approach, in the case of static and dynamic properties, and density functional theory, in the case of static electric properties, were used. The nonlinear optical (NLO) properties...
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In: International Journal of Quantum Chemistry, 2005, vol. 101, no. 6, p. 753-760
The cubic Prussian blue analogue Mn³[Mn(CN)₆]₂·15H₂O, which has the advantage of being transparent and magnetic (TN = 35 K) at the same time, has been investigated by density functional theory (DFT) calculations. The three-dimensional structure is built of MnII ions linked to MnIII ions by μ-bridging cyanides, to form a crystal structure,...
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In: International Journal of Quantum Chemistry, 2003, vol. 91 (3), p. 418-431
In this article, we present a theoretical investigation about the mechanism of the photochemical formation and deactivation of the metastable states observed in nitroprusside ions. The quantum chemical calculations are based on density functional theory. The peculiar photochemical and photophysical behavior of this molecule has attracted chemists' interest for a while. Due to this interest, many...
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In: International Journal of Quantum Chemistry, 2005, vol. 102, p. 119-131
Spin-orbit coupling has been introduced into our newly developed ligand field density functional theory (LFDFT), using the zero-order regular approximation as implemented into the Amsterdam density functional (ADF) code. Application of the formalism to a series of NiX₄²⁻ (X=F⁻, Cl⁻, Br⁻, I⁻) compounds shows the increasing importance of intra-ligand spin-orbit coupling across the F,...
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In: Physical Chemistry Chemical Physics, 2005, vol. 7(8), p. 1732-1738
In the present work, the ZORA spin–orbit Hamiltonian, in conjunction with the gauge including orbital (GIAO) method based on DFT theory has been used to calculate ¹⁹⁵Pt chemical shift of ¹⁹⁵PtClxBr6–x²⁻ complexes. Excellent agreement with experiments has been obtained for calculations bearing on optimized geometries and all electrons triple zeta +...
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