- Electrochemically prepared precursors for the formation of non-oxides
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Various metals, such as Ca, Mg, Al, Ti, Cr, Y, Zr, and Ta were anodically dissolved in an organic electrolyte composed of propylamine, acetonitrile, and tetrabutylammonium bromide. The electrode reactions were completely irreversible. At the cathode, the
- Russel,Zahneisen
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- Calcium carbodiimide compounds revisited - Syntheses, single crystal structure determination and vibrational spectra of Ca11N 6[CN2]2, Ca4N2[CN 2] and Ca[CN2]
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Single crystals of Ca11N6[CN2]2 (dark red needles, tetragonal, P42/mnm (no. 136), a = 1456.22(5), and c = 361.86(2) pm, Z = 2), Ca4N2[CN2] (transparent yellow needles, orthorhombic, Pnma (no. 62), a = 1146.51(11), b = 358.33(4), and c = 1385.77(13) pm, Z = 4) and Ca[CN2] (transparent, colorless, triangular plates, rhombohedral, R3?m (no. 166), a = 369.00(3), and c = 1477.5(3) pm, Z = 3) were obtained by the reaction of Na 2[CN2], CaCl2 and Ca3N2 (if demanded by stoichiometry) in arc-welded Ta ampoules at temperatures between 1200-1400 K. Their crystal structures were re-determined by means of single crystal X-ray structure analyses. Additionally, the Raman spectra were recorded on these same single crystals, whereas the IR spectra were obtained with the KBr pellet technique. The title compounds exhibit characteristic features for carbodiimide units with D∞h symmetry (d(C-N) = 121.7-123.8 pm and ≮(N-C-N) = 180°). The vibrational frequencies of these units are in the expected range (Ca11N6[CN2]2: vs = 1230, vs = 2008; δ = 673/645/624 cm -1; Ca4N2[CN2]: vs = 1230, vs = 1986; δ = 672/647 cm-1; Ca[CN 2]: vs = 1274, vs = 2031, δ = 668 cm -1). The structural results are more precise than the previously reported data, and with the newly attained Raman spectrum of Ca 11N6[CN2]2 we correct data reported earlier.
- Reckeweg, Olaf,DiSalvo, Francis J.
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- Solid state metathesis reactions as a conceptual tool in the synthesis of new materials
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Solid state metathesis reactions can be used in the syntheses of inorganic solids and for strategic design of novel, eventually thermally labile materials. An explorative study of solid state metathesis reactions is presented for a number of examples, including syntheses of nitridoborates, carbodiimides, tetracyanoborates, tetracyanamidosilicates, carbon-nitride materials, and a number of other exciting compounds. This unique type of reaction is very efficient because it uses the intrinsic energy of reaction partners being involved. Desired compositions are achieved by appropriate starting materials and their relative amounts being combined into a solid state metathesis reaction. Reactions can be controlled through the heating-up procedure and by using a reactive flux, which may lower the ignition temperature of a reaction mixture and promote crystal growth of products.
- Meyer, H.-Juergen
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p. 5973 - 5982
(2010/08/06)
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- Synthesis and characterization of carbon- and nitrogen-centered (Z) trigonal prismatic tungsten clusters of the formula type A[W6ZCl 18]
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Solid state reactions of tungsten(IV) chloride and carbodiimides (cyanamides) of lithium, sodium, calcium and silver yielded black crystalline powders of centered (Z) trigonal-prismatic tungsten cluster compounds having the general formula A[W6ZCl18] with A = Li, Na, Ca, Ag and Z = C, N. Crystal structures of the corresponding compounds were investigated by powder and single-crystal X-ray diffraction. The nature of the central atom was studied by mass spectrometry and nuclear magnetic resonance spectrometry. It turned out that the central atom can be C (in the case of the lithium and sodium compound) or N (in the case of the sodium and calcium compound).
- Weisser, Martina,Burgert, Ralf,Schnoeckel, Hansgeorg,Meyer, H.-Juergen
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p. 633 - 640
(2009/04/13)
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- 5,6-Dihydro-1,2,4,6-thiatriazin-5-one-1,1-dioxides
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5,6-Dihydro-1,2,4,6-thiatriazin-5-one-1,1-dioxides of the formula STR1 where R1 is hydrogen, a metal atom or an unsubstituted or substituted ammonium radical, R2 is a saturated or unsaturated straight-chain aliphatic radical of up to 10 carbon atoms, a cycloaliphatic radical or 3 to 7 carbon atoms, a branched saturated or unsaturated aliphatic radical of 3 to 10 carbon atoms, a halogen-, alkoxy- or alkylmercapto-substituted aliphatic radical of 2 to 10 carbon atoms tetrahydrofuryl substituted methyl, a cycloalkoxy-substituted aliphatic radical of 4 to 10 carbon atoms, unsubstituted or halogen-substituted benzyl or phenyl, halophenyl, or alkylphenyl of a total of up to 10 carbon atoms, R3 is hydrogen, a straight-chain aliphatic radical of up to 10 carbon atoms, a cycloaliphatic radical of 3 to 7 carbon atoms, a branched aliphatic radical of 3 to 10 carbon atoms, haloalkyl, or alkoxyalkyl of 2 to 10 carbon atoms and X is oxygen and may also be sulfur if R2 is unsubstituted or halogen-substituted benzyl, processes for their preparation, and herbicides containing the above compounds.
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- 1,2,3-Thiadiazole-3-in-5-ylidene-urea derivatives, process for making the same and compositions containing the same having growth regulating activity for plants
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1,2,3-Thiadiazole-3-in-5-ylidene-urea derivative of the formula STR1 in which R1 is hydrogen or alkyl which may be substituted in one or several places by oxygen or sulfur and wherein R2 and R3 have the meaning as given in the attached specification and wherein X is oxygen or sulfur. The compounds have properties suited for controlling the natural growth and natural development of plants and in addition have a superior defoliating property without accompanying unpleasant odors.
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- 1,2,3-Thiadiazole-2-id derivatives, process for making the same and composition containing the same having a growth regulating activity for plants
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1,2,3-Thiadiazole-2-id-derivative of the formula STR1 in which R1 is hydrogen or alkyl which may be substituted in one or several places by oxygen or sulfur and wherein R1 has the meaning as given in the attached specification and wherein X is oxygen or sulfur and B is a univalent metal atom. The compounds have properties suited for controlling the natural growth and natural development of plants and in addition have a superior defoliating property.
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