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  • Articles  (710)
  • Inorganic Chemistry  (658)
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  • 1985-1989  (710)
  • 1950-1954
  • 1987  (710)
  • 1
    Electronic Resource
    Electronic Resource
    A new method for the prediction of liquid pulsed sieve-tray extractorsLecture at the Annual Meeting of Chemical Engineers, September 19th to 21st 1984 in Munich. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 73-86 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: As a part of a research project on the mass transfer in liquid pulsed sieve-tray extraction columns (PSE), the diameters and hold-ups of the drops were measured: the drop size using a suction technique, with photoelectric detection, which was adapted to the special boundary conditions of the PSE; the integral hold-up by the pressure difference between the lower and upper parts of the column. Since experimental results cannot be described by known calculation formulae for the Sauter mean diameter and the hold-up, a new method of calculation was developed. It is phenomenologically based on high-speed photographs of the drop motion on a sieve tray. The mathematical-physical model allows the prediction of drop size and hold-up within certain limits, while the possible different operating regimes of the PSE, i.e. the mixer-settler and dispersion regimes can also be estimated.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100110
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  • 2
    Electronic Resource
    Electronic Resource
    Distillation columns with vertical partitions (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 92-98 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Distillation columns with vertical partitions can separate a feed mixture into 3 or 4 pure fractions. Compared to other column arrangements, their investment costs and energy consumption are lower. Production columns show good results and are easily controlled. Conventional distillation columns produce only 2 pure product streams at the top and at the bottom of the column. Side products are contaminated by light or heavy components, depending on the location of the side stream in the rectifying or stripping section. This disadvantage is set aside by using a distillation column with a vertical partition. The internal separation wall prevents lateral mixing of liquid and vapour in the central part of the column, forming there separate feed and outlet sections. In the presence of a vertical partition, 3 or 4 pure fractions can be obtained in a single distillation step. This is particularly advantageous when heat sensitive components are to be separated. On account of good thermodynamic properties, the energy consumption is 20 to 35% lower than that of other distillation arrangements. The control behaviour is similar or better than that of conventional distillation columns.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100112
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  • 3
    Electronic Resource
    Electronic Resource
    Fouling of heat transfer surfaces (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 113-125 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fouling and/or scaling of heat transfer surfaces causes serious problems in industry. Prevention of fouling is therefore essential for technical (considerable deterioration of heat transfer) and also economic reasons (increased costs). In order to provide successful countermeasures, it is, however, necessary to obtain more detailed information on the physical, chemical and biological processes which produce fouling. Based on the already known fouling mechanisms, it is shown that a satisfactory prediction of fouling behaviour of heat exchangers is not yet possible. This contribution presents a physical model for the description of fouling, caused by sedimentation and crystallization. It is assumed that, during fouling, deposition and removal processes overlap. In order to verify the theoretical considerations, experiments were carried out on a test rig, which could also be used for field experiments. Aqueous CaSO4 solutions served as experimental liquids. A comparison of experimental and calculated fouling factors shows a satisfactory agreement.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100115
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  • 4
    Electronic Resource
    Electronic Resource
    Calculation of primary bubble volume in gravitational and centrifugal fieldsModified version of a paper presented at the meeting of “GVC Subject group: Mehrphasenströmung”, Kaiserslautern, February 20th, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 99-103 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A one-stage model of the formation of primary bubbles is presented in which the bubble volume is deduced from an equilibrium of buoyancy, viscosity, inertia and surface tension forces. In contrast to the two-stage model, presented by Kumar and Kuloor, it was not assumed that the drag coefficient in bubble expansion can be described by the same constants as in the steady-state bubble ascent. The constants were adapted in such a way that the introduction of an additional bubble volume was not necessary. It was demonstrated that this model describes the bubble formation in gravitational and centrifugal fields equally well and, furthermore, is also applicable to structurally viscous liquids, provided that the effective shear gradient \documentclass{article}\pagestyle{empty}\begin{document}$$ \mathop {\rm \gamma }\limits^. = \frac{1}{6}({\rm \Delta \rho }gzd_{\rm B} /{\rm \eta }) $$\end{document} is calculated from the equilibrium of shearing and buoyancy forces. The model is based on the assumption of a constant volumetric flow rate during bubble formation and, for this reason, a minimum Froude number is necessary in analogy to the weeping limit for sieve plates. The normalized presentation permits simple operation. The possibility of applying the model to drop formation was confirmed by comparison of experimental values with those, predicted by the model.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100113
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  • 5
    Electronic Resource
    Electronic Resource
    Tentative modelling of spray-dry scrubbing of SO2 (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 104-112 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A 0.5 MW spray-dry scrubbing FGD pilot plant was used in the study of spray dryer performance over a wide range of operating conditions. Experimental findings were compared with a spray dryer model. During operation with large excesses of lime, the SO2 absorption was limited by gas phase diffusion. At operation with a shortage of lime, the rate limiting step was the dissolution rate of lime. In addition, the flow regime in a spray dryer can be best described as well mixed. The SO2 level in the flue gas was found to exert no direct effect on the efficiency of SO2 removal. The observed effects are attributed solely to the changes in the drying process, due to the inter-dependence of slurry composition and SO2 concentration.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100114
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  • 6
    Electronic Resource
    Electronic Resource
    Continuous deasphalting of heavy petroleum residues with ethyl acetate (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 125-131 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: When crude oil is vacuum distilled, about 30% of the feed remain as low value residue. Hydrocracking can upgrade this residue into valuable light hydrocarbons. The hydrocracking could be optimized catalytically, if the residue were not to contain the metals vanadium and nickel that poison the catalyst. This contribution shows that continuous extraction of the residue with ethyl acetate yields a fraction with low metal content, while an asphaltene fraction with the remaining metal content is filtered off.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100116
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  • 7
    Electronic Resource
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    New equipment for the determination of virial coefficients of pure substances and binary mixturesDedicated to Professor Dr. Kurt Hedden on the occasion of his sixtieth birthday (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 143-150 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new equipment for the measurement of virial coefficients of pure substances and binary mixtures is described. It consists of an improved modification of the set-up proposed by Eucken and Meyer in 1929. The development is based on a critical review of the existing methods particularly with respect to adsorption effects. In order to reduce the influence of adsorption on the accuracy of virial coefficients, an optimum range for gas density is recommended. The accuracy of the virial coefficients is better than 20 cm3 mol-1. The set-up was employed for the measurement of virial coefficients of acetone and hexane in the range from 352.95 to 393.85 K. The results are in excellent agreement with data published in literature. Furthermore, cross-virial coefficients of the binary system acetone/hexane were measured and interpreted.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100118
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  • 8
    Electronic Resource
    Electronic Resource
    Influence of electrolytes on the absorption of nitrogen oxide components N2O4 and N2O3 in aqueous absorbents (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 131-142 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The influence of electrolytes, which are dissolved in the aqueous absorbent and do not react with nitrogen oxides, on the absorption kinetics of both these components was investigated experimentally. In addition to demineralized water, various salt solutions of different concentrations as well as sodium hydroxide solution were used as absorbents. The term H \documentclass{article}\pagestyle{empty}\begin{document}$ H\sqrt {k_1 D} $\end{document} for N2O4 and N2O3, which is important for the design of industrial absorbers, was determined as a function of composition and concentration of the absorbents. In the case of N2O4, the chosen measuring and evaluation methods permitted a separate determination of the rate constant k of the pseudo first order reaction and of the solubility H. The diffusion coefficient D of the gas in the absorbent can be obtained only by calculation. Experimental results showed that \documentclass{article}\pagestyle{empty}\begin{document}$(H\sqrt {k_1 D} )\,_{{\rm N}_{\rm 2} {\rm O}_{\rm 4} } $\end{document} decreases with increasing ionic strength I, however, without a clear indication of any ion-specific effects. This decrease does not appear to be caused simply by a reduction in solubility (salting out effect), or in diffusion coefficient, but at least, to the same extent, through a decrease of the rate constant k with increasing electrolyte content in the absorbent. The measurements permitted the determination of the gas-based salting out parameter for N2O4. The investigations on the absorption of N2O3 in water and in an Na2SO4 solution showed no experimentally detectable influence of dissolved salts on \documentclass{article}\pagestyle{empty}\begin{document}$(H\sqrt {k_1 D} )\,_{{\rm N}_{\rm 2} {\rm O}_{\rm 3} } $\end{document}. The numerical value of \documentclass{article}\pagestyle{empty}\begin{document}$(H\sqrt {k_1 D} )\,_{{\rm N}_{\rm 2} {\rm O}_{\rm 3} } $\end{document} is six times that of \documentclass{article}\pagestyle{empty}\begin{document}$(H\sqrt {k_1 D} )\,_{{\rm N}_{\rm 2} {\rm O}_{\rm 4} } $\end{document}.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100117
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  • 9
    Electronic Resource
    Electronic Resource
    Simulation of fluid dynamics in a pulsed sieve plate columnLecture at the “Jahrestreffen der Verfahrensingenieure”, 17. to 19. September 1986 in Strasbourg. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 151-157 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The present contribution reports on a new method for the simulation of the dispersed phase behaviour in liquid-liquid extraction columns. The fluid dynamic description is based on a mathematical model which explicitly takes into account drop transport, break-up and coalescence mechanisms, via a drop population balance along the column. Application of the model requires some simple measurements on single drops in order to determine transport and break-up laws, which are required by the model, and possibly also coalescence parameters. In this study the model is applied to pulsed sieve plate columns. The specific example considered here is based on systematic studies on the determination of break-up rates from the corresponding probabilities of break-up and the generated daughter drop size distributions by means of high-speed photography. The validity of the model was subsequently tested by comparison with some experimental results from studies on two different pulsed columns 80 and 225 mm in diameter for the water/toluene system without mass transfer. The satisfactory agreement between the results justifies the use of such a method for the description of the behaviour of liquid-liquid extraction columns in a wide range of operating conditions. Furthermore, application of the model may help to dispense with long and expensive pilot tests.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100119
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  • 10
    Electronic Resource
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    Computer-aided design of tube-bundle heat exchangers (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 157-164 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Based on a paper by Hein, a dimensioning program for tube-bundle heat exchangers with straight tubes and fixed tube sheets has been developed. The equipment to be dimensioned is tested at 14 critical points, with regard to permissible stresses. The optimum thickness of the tube sheet, the shell and channel are subsequently selected on the basis of economic criteria. Compared to dimensioning according to AD-data sheet, it is possible to save between 10 and 25% of production costs. With the aid of a finite-element (FE) program, complex structures such as heat exchangers can be calculated accurately. Several mesh-generation programs were written for the data input. The structure of a tube-bundle heat exchanger with straight tubes is generated with 3/D elements with only some geometrical data. An FE-calculation of a heat exchanger is explained with the aid of an example and stress analysis is presented.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100120
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  • 11
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    DIVA - a flow-sheet oriented dynamic process simulatorExtended version of a lecture presented by W. Marquardt at Jahrestreffen 1986 der Verfahrensingenieure, Strasbourg, 17. to 19. September 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 164-173 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The detailed dynamic simulation of coupled process units in chemical plants is gaining an increasing importance as a useful tool in plant engineering and operation. The outline of the program package DIVA (Dynamische Simulation verfahrenstechnischer Anlagen) which is currently under development is presented in the following. The dynamic plant equations and the corresponding Jacobian matrix are generated automatically. The full exploitation of sparse matrix techniques in combination with stiff ODE (ordinary differential equation) solvers allows an efficient solution of all the equations simultaneously. The possibilities offered by the simulator are demonstrated by the simulation of two laboratory plants.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100121
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  • 12
    Electronic Resource
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    Fluid dynamics and mass transfer in a bubble column with suspended particlesPaper presented at the Annual Meeting of German Chemical and Process Engineers (GVC, VDI) 1986, September 17 to 19 Strasbourg. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 180-189 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Slurry bubble columns are widely used in biotechnology. Therefore, the effects of solid particles on fluidization characteristics, gas hold-up and volumetric liquid-side mass transfer coefficient were measured in a slurry bubble column (i.d. 0.14 m). The density and diameter of the suspended particles were similar to those applied in biotechnology with immobilized bacteria. Based on models of turbulence and of liquid circulation induced by rising gas bubbles, equations for critical gas velocity, gas hold-up and volumetric liquid-side mass transfer coefficient were obtained by dimensional analysis.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100123
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  • 13
    Electronic Resource
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    Contact-free measurements of oxygen concentration in industrial flames by raman scattering (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 190-203 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Spatially resolved oxygen concentration measurements were performed in premixed hydrocarbon flames by using laser induced spontaneous Raman scattering. The measurements demonstrate the performance of a relatively simple pulsed laser Raman probe for fundamental combustion studies and also for the control of the equivalence ratio in flames (best spatial resolution: 0.2 mm3; theoretical detection limit: 0.8% of O2). Comparison of the results with those obtained by a mechanical suction probe (Magnos 2 T) confirmed a good agreement. At present, control of different stoichiometric conditions is possible at a minimum O2 concentration of 1.3%.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100124
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  • 14
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    Microbial desulphurization of coal - development and application of a slurry reactorPaper presented at the “Jahrestreffen der Verfahrensingenieure”, 17. to 19. September 1986 in Strasbourg (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 173-179 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Microbial desulphurization of coal by pyrite oxidizing enrichment cultures containing predominantly Thiobacillus ferrooxidans was performed in an air-agitated slurry reactor, 20 l in volume. A model of microbiological and chemical reactions, occurring at various points within the coal, was set up taking into account the pore structure of the coal. The influence of parameters relevant to industrial processes, such as superficial gas velocity, particle size, initial pyrite concentration, and slurry density of the coal, on the conversion of pyrite was examined. Variation of the superficial gas velocity in the range of 0.01 to 0.04 m/s confirmed that the reaction is not controlled by oxygen transfer from gaseous to liquid phase. The rate of pyrite oxidation depends mainly on the accessibility of pyrite to micro-organisms which is determined by the particle size of the coal as well as the distribution of pyrite crystals in the coal matrix. The accessibility of pyrite to the micro-organisms is described by the ratio of effective to maximum microbial activity, measured as oxygen consumption. Starting with higher initial concentration of pyrite in the coal increases the oxidation rate, according to first order kinetics. Enhanced slurry densities lead to a decrease of pyrite conversion, in spite of higher pyrite concentration. The maximum pyrite oxidation rate was measured at 15% (v/v) slurry density and 25°C as 1800 mg Spyr/kg coal per day, or 360 mg Spyr/l reactor volume per day.
    Additional Material: 13 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100122
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  • 15
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    Rear surface deposition of fine particles on spheres  -  eddy deposition or electrostatic effects? (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 330-337 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The aim of this investigation is to show the demarcation of two possible mechanisms for surface deposition of fine particles on the rear surface of single spheres. By means of single particle trajectory computation, based on numerically determined flow fields (Remax = 103), it is shown that the mere existence of a wake is not in itself sufficient to produce eddy deposition. In addition, the particle's motion must undergo a lateral transfer promoted by fluid trubulence, in order to effect eddy deposition commencing at a Reynolds number of about 100. On the other hand, rear deposition, influenced by electrostatic forces, especially by the Coulomb force, is possible at any Reynolds number. Consequently, for Reynolds numbers of less than 100, only electrostatic effects can produce rear surface deposition. In the range of high Reynolds numbers, the coexistence of both mechanisms is possible. Very high Reynolds numbers (Re 〉 103) and low Stokes numbers indicated the predominance of the electrostatic effect over eddy deposition, whereas at very high Reynolds numbers and medium to high Stokes numbers the electrostatic effect is only predominant in presence of high electrostatic charges.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100140
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  • 16
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    Kinetic studies on catalytic methanation by means of a concentration-controlled recycle reactor (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 361-367 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The rate behaviour of multi-step reaction systems is difficult to model. Concentration-controlled investigations in a recycle reactor provide new tools for this purpose, e.g. the possibility to decompose a network into single reaction steps. Methanation of carbon monoxide over a supported Ni catalyst could be shown to be accompanied to a considerable extent by the shift reaction, and to a lesser extent by direct hydrogenation of carbon dioxide. Deactivation of the catalyst was measured at definite gas compositions. The two main steps show different responses to deactivation: Separable kinetics was found only for the methanation step. Power law rate equations were fitted to the rate data of the individual reaction steps to represent the main features of their kinetic behaviour. Some aspects of deactivation kinetics are also discussed.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100144
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  • 17
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    Investigation of entrainment in tray columns (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 224-230 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper describes a pilot plant for entrainment measurements on various types of column trays. The data obtained from different trays differ by up to a factor of 10. The measurements were compared with the theoretical model of Stichlmair. The Stichlmair entrainment diagram permits a fairly accurate prediction for most types of trays if the height of the two-phase layer is known. Prediction of the height and relative liquid hold-up in this two-phase system should be modified by a term reflecting the vapour flow profile, which requires further testing. These tests should examine the effect of tray spacing, fractional free area and, in particular, the influence of different media.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100127
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  • 18
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    Pressure drop and flooding in packed columns operating at high pressuresPresented at the joint session of the GVC Subject Group for “Thermal Separation of Gas and Liquid Mixtures” on 9th to 10th May 1985 in Bergheim/Austria. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 231-242 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Correlations for pressure drop and upper capacity limit (flooding) are useful for the design of packed columns. Available correlations are based on the results of measurements made at atmospheric pressure. Extrapolation to higher pressures is not recommended. Therefore, systematic experimental investigations were carried out in a pilot plant at pressures of up to 100 bar. The experimental equipment and techniques, evaluation methods, and some characteristic experimental results are presented.
    Additional Material: 16 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100128
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  • 19
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    Heat transfer in boiling of multicomponent mixturesPaper presented at GVC-Conference bAden-Baden (FRG) 25./26. April 1985. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 242-248 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pool boiling data of multicomponent mixtures show that the heat transfer coefficients can be considerably lower than those of a corresponding pure fluid with the same physical properties as the mixture. The proposed model, which assumes maximum mass transfer resistance in the liquid boundary layer, is confirmed by the comparison between calculated and experimental data. The model allows the prediction of heat transfer coefficients in pool boiling of mixtures using only single component properties and vapour-liquid equilibrium data. Judging by experience with a number of different systems, the method should be sufficiently accurate for most practical applications.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100129
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  • 20
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    Pressure pulsations in the piping of reciprocating pumps (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 262-271 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pressure pulsations in hydraulic systems, generated by reciprocating pumps, can cause serious problems with regard to plant safety and reliability. In particular, fatigue problems arise in high-pressure piping systems. The available knowledge is not sufficient for an accurate computation of pressure peaks in the piping of reciprocating pumps. A number of calculation models are available which, however, neglect both fluid compressibility and friction. This contribution presents a calculation method which allows a precise modelling of various pump installations. Comparison of calculated and experimental data shows a good agreement and provides a validation of the computational model.
    Additional Material: 18 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100132
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    Scale-up of power consumption in agitated ball millsLecture at the “Jahrestreffen der Verfahrens-Ingenieure”, Strasbourg, September 17 to 19, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 398-404 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Previous investigations have shown that the specific energy input is the overall parameter of influence on product size during communition in agitated ball mills, from laboratory up to industrial scale. The specific energy input is the introduced energy related to the amount of comminuted material. This parameter can be used for mill scale-up. Consequently, a method had to be found of introducing power into the mill so as to obtain a given specific energy input. For this purpose, stirring tests with purely Newtonian liquids were carried out in absence of solids and hence, without comminution. Mathematical models are presented which describe the power consumption in agitated ball mills in absence of grinding beads. In addition, tests with grinding beads filling were also performed, leading to scale-up guidelines with respect to power consumption. Finally, the influence of size and material of grinding beads was investigated.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100149
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    Density of desublimed layers (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 405-410 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Starting from the assumption that the growth of desublimed layers is governed mainly by heat and mass transfer, the authors present a model based on conditions in the diffusion boundary layer and suggest that the “hoarfrost”Hereafter the term frost will be used instead of hoarfrost. density depends on only one parameter. The discussion accounts for the process determining factors, i.e. the growth rate, mass transfer and gas concentration. The theoretical relationship is confirmed by the authors' own experiments on two systems and data from literature. The relationship can be established by a few laboratory experiments and permits the calculation of frost density and of associated variables, thus facilitating the optimization of desublimator design.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100150
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    Theory and application of an alternative correlation flowmeter (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 353-360 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Correlation flowmeters have been used in the scientific field for many years and are actually gaining greater commercial importance due to an increasing number of applications in industrial plants. The importance of the correlation method is based on the fact that essentially no alternatives exist for measuring velocity and mass flow rate in pneumatic conveyors. However, the hitherto employed transit time correlation method leads to results which are clouded by uncertainties. The commonly used theoretical model of the measurement process does not explain these effects satisfactorily. Therefore, the theory of non-intrusive flow sensors is reinvestigated from a physical standpoint. The derived model permits a discussion of the transit time correlation method in some detail. Furthermore, this model leads to an alternative sensor arrangement and signal processing scheme which makes it possible to measure the true mean velocities. Examples of experimental results are given.
    Additional Material: 13 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100143
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    Dynamics of distillation with high product puritiesExtended version of a paper presented by Dr. G. Wozny at the internal group meeting of the GVC Technical Committee on “Mass Transfer Processes” and “High-Pressure Process Engineering”, April 10 to 11, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 338-348 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: For the simulation of steady- and non-steady-state behaiour of separation columns, a simulation program was developed and employed for the calculation and optimization of methanol-water separation. The demand for increasingly higher purities and energy-saving optimization of plants results in complex column configurations and thus in complex control schemes. The number of possible control schemes was reduced on the basis of heuristic rules. By simulating the process, the optimum control and manipulative variables and measuring points were determined from the reduced number of control concepts. A control scheme was introduced. The model was verified by simulation of the dynamic behaviour of the process. The investigation included the effects of computing technique, time interval, model reduction and tray hold-up on the results. Thus, various effects and interactions were verified theoretically with respect to the robustness of the model. This was followed by a simulation of the non-ontrolled and controlled column. By implementing the controllers in the existing column program, the computer can predict the control parameters. These parameters were checked and corrected when the metahnol-ater column was put in operation. In the start-up phase, major problems were caused by the sensitivity and failure rate of density, throughput and pump measuring sensors. Feed impurities were another source of problems. Operation with high product purities is possible, with a side stream to discharge impurities.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100141
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    Bubble flow in pressurized gas/solid fluidized beds (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 368-375 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This contribution presents the measurements of bubble behaviour in presence of A, B and D powders in a semi-industrial scale pressurized fluidized bed. Local measurements were taken at static pressures of 0.2, 1.0 and 2.5 MPa, using capacitance probes. Quartz sand with mean particle diameter of 157 μm was fluidized in small “two-dimensional” transparent equipment with Frigen R 115. In addition, pressure fluctuations in the bulk of the fluidized bed with inner diameter of 0.4 m were studied experimentally.
    Additional Material: 13 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100145
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    Local energy dissipation in agitated turbulent fluids and its significance for the design of stirring equipment (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 56-63 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Ideal flow conditions are generally assumed for the reactor design. If stoichiometry, reaction mechanism and kinetics are known, the balance equations for the ideal flow tube, the ideal steady-state continuous stirred tank reactor or the ideal, completely mixed stirred batch reactor are often applied. In many cases, formal kinetics, which forms the basis of reaction modelling, is so uncertain that the idealization of the flow field can be accepted. In practice, however, deviations from the ideally calculated conversions, yields and product qualities, often occur. In these cases, it is necessary to consider the real flow conditions. In general, a distinction is made between macroand micromixing processes.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100108
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    Reaction models for simulation of the oxidation of carbon monoxide in turbulent diffusion flames (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 43-55 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The oxidation of carbon monoxide by air in a turbulent flow was investigated under experimental conditions where the rates of turbulent mixing and of chemical reaction are comparable. For this purpose, carbon monoxide was admixed into the completely burnt gas of a natural gas flame operated with excess of air. Measurements of mean values of axial velocity, temperature and volume fractions of carbon monoxide and oxygen were compared with computational simulations involving the k - ∊ turbulence model and several turbulent reaction models for the oxidation of carbon monoxide. The comparison of measurements and numerical calculations demonstrated that the k - ∊ turbulence model is suitable for prediction of the turbulent flow field in the flow system investigated. Furthermore, it could be shown that one-variable turbulent reaction models, such as the flamesheet or the eddy-break-up model, cannot explain the measured carbon monoxide volume fraction profiles. Two-variable turbulent reaction models with a probability density function closure of the source term of the transport equation for the mass fraction of the chemical species result in a better agreement between the measured and simulated volume fraction profiles, particularly in predicting the clear influence of the initial temperature on carbon monoxide volume fractions. Weighting of the kinetic rate expression for the oxidation of carbon monoxide with different presumed probability density functions yields slightly different predictions of the carbon monoxide volume fractions, reflecting the assumed different character of turbulent fluctuations.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100107
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    Kinetics of removal of impurities from gases by high pressure adsorption (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 63-72 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Among other processes, adsorption is used for the removal of hydrogen sulphide from natural gases. Hereby, competitive adsorption of the different gas components plays an important role, e.g., that of carbon dioxide. Data of equilibrium loading and adsorption kinetics are required for the design of adsorbers, filled with molecular sieve. In order to obtain these data under the prevailing operating conditions, hydrogen sulphide was removed from gas mixtures H2S/CH4 and H2S/CO2/CH4, in a pilot plant, by adsorption on molecular sieve 5A. The equilibrium loading, the height of transfer zone, and the length of unused bed were determined from the measured breakthrough curves of H2S. With these data, the breakthrough time and the optimum process conditions were calculated for a practical example.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100109
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    Advances in gas permeability measurements (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 86-92 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The Carman-Arnell equation relates the rate of flow of a fluid through a packed bed to the pressure drop across the bed. This equation is the basis for surface area determination by permeametry. It is found that the surface area measured at sub-atmospheric pressure varies with the bed porosity, so a porosity was selected where the rate of change was at a minimum. The study suggests that, at reduced pressures, the gas flow rate is a linear function of the mean pressure.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100111
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    Masthead (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987) 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100101
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    Mass transfer area in different gas-liquid reactors as a function of liquid properties (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 1-15 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Using pilot-scale test plant, the interfacial area per unit volume was investigated in different gasliquid reactors, i.e. packed column, bubble column and free jet reactor. The interfacial area was studied as a function of liquid viscosity and of operating parameters. As a rule, identical test conditions were maintained in all the measurements, in order to obtain comparable results. The interfacial area was determined by chemical means using the sulphite system (a solution of sodium sulphite in water as model liquid and air as gaseous medium). The viscosity of the solution can be increased by adding carboxymethyl cellulose without significantly affecting the reaction kinetics. The addition of a surfactant to the sulphite system allowed comparative measurements at reduced surface tension. Based on a large number of measurements, the correlations of the interfacial area are expressed as power laws. The inclusion of experiments with a jet tube reactor and a stirring vessel allows an extensive comparison of all reactors. All tests were carried out with the same material system and the same method was used to determine the interfacial area per unit volume. Therefore, a comparison with respect to mass transfer is possible.
    Additional Material: 21 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100102
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    Use of carbon dioxide in industrial organic syntheses (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 16-27 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Although carbon dixoide is important as an abundant carbonaceous raw material, so far, its utilization in chemical processes has been rather limited. This review covers the reactions of CO2 employed in industry, such as the production of urea, the Kolbe-Schmitt reaction, the synthesis of cyclic organic carbonates and the use of CO2 in methanol synthesis. Interesting recent developments in CO2 chemistry, such as the reactions catalyzed by transition metals, are also described. Apart from the synthesis of polymers and hydrocarbons, the production of oxygen-containing substances appears to be very profitable and attractive for future industrial applications. Not only can derivatives of formic and carbonic acids be produced but also longer-chain carboxylic acids and their derivatives by reactions of carbon dioxide with hydrocarbons such as alkynes, alkenes and 1,3-dienes.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100103
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    A new method for measuring local velocities of the continuous liquid phase in strongly aerated gas-liquid multiphase reactors (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 27-32 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new measurement method for determining the local liquid-phase velocities in multiphase flows is presented. It is based on a tracer technique, using heat introduced into the flow, seemingly at random, instead of a material tracer. The input of heat pulses and measurement of temperature at an adjacent point is performed by small probes. As an intermediate result, the flow time distribution of the heat-labelled fluid elements is calculated on-line as a cross-correlation function between the pseudo-random input and the measured output signals. This calculation and the automatic control of measurements is carried out by a simple microprocessor unit. The device produced excellent results in gas-liquid flows at high gas throughputs and high liquid-phase velocities.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100104
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    Liquid channelling on trays and its effect on plate efficiency (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 33-37 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: All the present experiments confirm that there is some liquid channelling on trays. Liquid channelling is extensive on trays of large diameters. It largely depends on the tilting of the plate, modifications of the inlet weirs and on non-uniform bubble cap spacing. Consequences of liquid channelling for plate efficiency are clear; the higher the degree of liquid channelling the lower the plate efficiency. However, own experimental and theoretical investigations indicate that plate efficiency never falls below the value of point efficiency. Therefore, liquid channelling only affects the crossflow on trays. Liquid channelling reduces the mass transfer performance to a similar extent as does the backmixing of liquid. Consequently, plate efficiency is not very sensitive to liquid channelling. Since the liquid is completely mixed in the downcomer, the effects of liquid channelling are restricted to a single tray. The behaviour of tray columns completely differs from that of packed columns, where the effects of liquid channelling are cumulative over the packed height. Consequently, trays represent a suitable design for columns of large diameters.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100105
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    The separation of lecithin and soya oil in a countercurrent column by near critical fluid extractionLecture at the “Jahrestreffen der Verfahrens-Ingenieure”, Hamburg 25. to 27. Sept. 1985. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 37-42 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The present contribution illustrates a way of developing a continuous separation process for near critical fluid extraction, on the example of separation of soya oil from lecithin. First, a suitable solvent was selected. Phase equilibria were measured in autoclaves. Operating conditions for a pilot plant were derived from the phase equilibrium data. The pilot plant experiments provided the necessary data for designing a production plant. Computer programs for phase equilibrium, stage to stage and mass and heat balance calculations were used in order to minimize the number of experiments. A production plant with a capacity of 500 t/a of raw lecithin was designed on the basis of experimental and computational results. A cost estimation, based on tenders, showed that it is more economical to produce lecithin by near critical fluid extraction than by conventional acetone extraction.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100106
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    Modelling of adsorption in cyclic operation of a PSA plant for H2 recoveryLecture by H. Brüggendick at the “Jahrestreffen der Verfahrensingenieure”, 17. to 19. September 1986 in Strasbourg. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 390-398 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A pressure swing adsorption process for hydrogen recovery from coke oven gases comprises the steps of adsorption at pressures above 6 bar, cocurrent and countercurrent depressurization, purging with hydrogen at ambient pressure and repressurization. The process was investigated in the cyclic mode, on a laboratory scale, using an adsorber filled with 1.3 litres of carbon molecular sieve. Based on the test results of concentrations and pressures within the adsorber during complete cycles, a pseudo-homogeneous model was developed for the adsorption step. Adsorption equilibrium parameters were determined by separate measurements, while the transport parameters were evaluated by fitting the experiments of the fixed bed adsorber. It was possible to consider the residual load, resulting from an incomplete regeneration, by the assumption of a load distribution in the inlet region of the adsorber.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100148
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    Steam reforming of natural gas with intergrated hydrogen separation for hydrogen production (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 248-255 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The development of heat resistant permeation membranes has opened up new possibilities for the conversion of fossil energy resources. In steam reforming of natural gas, such membranes even permit a direct production of hydrogen at high temperatures during the conversion of feed hydrocarbons. Further gas processing, such as required for reformer gas in existing hydrogen production processes, is not necessary. Due to continuous hydrogen discharge directly in the reformer tube, the chemical equilibrium of the occurring reactions becomes displaced towards the products, resulting in more favourable process conditions and, consequently, in improved by 36% utilization of the feed hydrocarbons. At the same time, the hydrogen yield increases by 44%. The heat required, which is provided by a high temperature reactor, is 17% in excess of that in conventional plants. It can be expected that the simplified process design will produce substantial cost advantages over the existing processes for the production of hydrogen.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100130
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    Calculation of reactive extraction in countercurrent columns (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 291-296 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetics of extraction processes with chemical reaction was studied experimentally on the system copper/Acorga PT 5050 and quantified according to meaningful kinetic models. These were coupled with other models describing the behaviour of dispersions in columns in order to permit a computer aided simultation of reactive extraction. Thus, a better prediction of column performance is achieved.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100135
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    Influence of temperature and properties of solids on the size and growth of bubbles in gas fluidized bedsPaper presented at the annual GVC meeting, Spetember 17-19, 1986, Strasbourg/France. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 272-280 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the present paper, models are developed for the description of coalescence and splitting of bubbles in gas fluidized beds. The distinction between slow and fast bubbles, which originates from the Davidson model of gas flow in and around a rising bubble, was found to be decisive for the modelling of coalescence processes. On the basis of the respective models, it is shown that a change in bed temperature does influence the mechanisms of both bubble coalescence and splitting. In cases of both slow and fast bubbles undergoing splitting, the theory predicts a decrease of bubble size with temperature whereas in the case of a non-splitting system with fast bubbles, typically encountered with Geldart type B particles, no significant temperature effect on bubble size is expected. The theoretical predictions are shown to be in agreement with own measurements as well as with the results of other workers.
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    URL: http://dx.doi.org/10.1002/ceat.270100133
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    Particle velocity in a stratified two-phase flow between inclined parallel plates (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 281-289 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fundamental investigations of coalescence processes in settlers with plate packages for the separation of liquid-liquid dispersions prompted an analysis of the drop motion on the interface of a stratified two-phase flow. Therefore, a physical model was developed, which permits the calculation of drop velocity along the interface of an inclined trickling film. Starting from a balance of forces around a single particle, the model provides the equation of motion for a steady motion of single particles in a stratified two-phase flow. Several assumptions and considerations were necessary to solve this equation, such as taking into account the influence of the wall and of flow resistance. The model calculation assumes Newtonian liquids and laminar, smooth trickling films. A comparison with experimental results confirms that the drop motion behaviour is well reproduced.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100134
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    Methyl Shifts in 1,4-Dipoles from Sulfonyl Isocyanates and Ketene O,N-Acetals (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 335-337 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bei niedriger Temperatur reagieren Sulfonylisocyanate 1 und Keten-O,N-acetale 2 zu 1,4-Dipolen 3. Beim Erwärmen lagern sich die Dipole 3 in einer formalen O→N-Methyl-Wanderung zu Malonamiden 4 um. Ausgehend von 2a und 2b mit deuterierter O-Methyl-Gruppe gab ein Kreuzungsversuch halbdeuterierte Produkte und bewies so, daß die Methyl-Verschiebung intermolekular verläuft.
    Notes: At low temperature, sulfonyl isocyanates 1 react with ketene O,N-acetals 2 to give 1,4-dipoles 3. On warming, dipoles 3 rearrange in a formal O→N methyl sift to give malonamides 4. A crossover experiment starting from 2a and 2b with a deuterated O-methyl group gave scrambling of the label and thus confirmed the intermolecular nature of the methyl transfer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19871200314
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    Unsymmetrisch gebaute (Pd - Pd)-Zweikernkomplexe mit CO, CNR, SO2 und C2(CO2Me)2 als Brückenliganden (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 365-372 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The reaction of the cyclopentadienyl- and halide-bridged dinuclear complexes (μ-C5H5)(μ-X)Pd2(PEt3)2 (1a, b) und (μ-C5H5)(μ-X)Pd2(piPr3)2(2a, b) mit CO, CNR (R=CH3, C6H5, p-CH3C6H4), SO2 und C2(CO2Me)2 leads almost quantitatively to the formation of the compounds C5H5(PR3)Pd(μ-E)Pd(PR3)X (3, 4, 6-11), in which the bridging ligand E E [CO, CNR, SO2, C2(CO2Me)2] is unsymmetrically linked to the two electronically different molecular fragments C5H5(PR3)Pd and Pd(PR3)X. The addition of E occurs without cleavage of the metal-metal bond. C5H5(PEt3)Pd(μ-CO)Pd(PEt3)Br (3b) reacts smoothly with SO2 to produce C5H5(PEt3)Pd(μ-SO2)Pd(PEt3)Br (9b); exchange of the bridging ligand in the reverse direction does not occur. The structure of the complexes C5H5(PiPr3)Pd(PiPr3)Cl (4a) und 9b has been determined by X-ray analysis.
    Notes: Die Reaktion der Cyclopentadienyl- und Halogen-verbrückten Zweikernkomplexe (μ-C5H5)(μ-X)Pd2(PEt3)2 (1a, b) und (μ-C5H5)(μ-X)Pd2(piPr3)2(2a, b) mit CO, CNR (R=CH3, C6H5, p-CH3C6H4), SO2 und C2(CO2Me)2 führt nahezu quantitativ zu den Verbindungen C5H5(PR3)Pd(μ-E)Pd(PR3)X (3, 4, 6-11), in denen der Brückenligand E [CO, CNR, SO2, C2(CO2Me)2] unsymmetrisch an die beiden elektronisch ungleichen Molekülfragmente C5H5(PR3)Pd und Pd(PR3)X gebunden ist. Die Addition von E verläuft ohne Spaltung der Metall-Metall-Bindung. C5H5(PEt3)-Pd(μ-CO)Pd(PEt3)Br (3b) reagiert mit SO2 sehr rasch zu C5H5(PEt3)Pd(μ-SO2)Pd(PEt3)Br (9b); ein Brückenaustausch in umgekehrter Richtung ist nicht möglich. Die Struktur der Komplexe C5H5(PiPr3)Pd(PiPr3)Cl (4a) und 9b wird durch Röntgenstrukturanalyse bestimmt.
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    Alkyl Shifts in 1,4-Dipoles from Tosyl Iso(thio)cyanate and Imido(thio)carbonates or Isoureas (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 339-344 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Die Dipole 3, 13 aus Tosylisocyanat (2a) und Imido(thio)kohlensäureestern 1 (12) geben O → N-Alkyl-Verschiebungen zu (Thio)Allophansäureestern 5 (14). ähnlich führt die Addition von Tosylisothiocyanat (2b) an den Isoharnstoff 24a zum Produkt 28 einer O→S-Methyl-Verschiebung. Ausgehend von 2a und den Imidothiokohlensäureestern 12b,c ergab ein Kreuzungsversuch die vier Produkte 14a-d und bewies so den intermolekularen Verlauf der Umlagerung. Beim Zusammengeben des Isothiocyanats 2b und der Imido(thio)kohlensäureester 1 (12) oder von 2a und der Isoharnstoffe 24a,b bleibt die Reaktion jedoch auf der Stufe der Dipole 8, 19, 25a, b stehen.
    Notes: O→N alkyl shifts are observed in the dipoles 3, 13 from tosyl isocyanate (2a) and imido(thio)carbonates 1 (12) to give (thio)allophanates 5 (14). Similarly, addition of tosyl isothiocyanate (2b) to isourea 24a leads to the product 28 of an O → S methyl shift. A cross-over experiment involving 2a and imidothiocarbonates 12b,c gives the four products 14a-d proving the intermolecular nature of the rearrangement. However, on mixing 2a and isoureas 24a,b or 2b and imido(thio)carbonates 1 (12), the reaction stops at the stage of dipoles 8, 19, 25a,b.
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    Beiträge zur Chemie des Bors, 182 Versuche zur Darstellung von Methylenboranen: Untersuchungen zur Dehydrohalogenierung sterisch anspruchsvoller Amino-organylborhalogenide (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 345-350 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: LiCMe3 reacts with tmpB(Hal)CHMe2 with substitution to give tmpB(CMe3)CHMe2 (tmp=2,2,6,6-tetramethylpiperidino) but not by dehydrohalogenation. In the presence of Me2NCH2-CH2NMe2 the aminoborane tmpB(NMe2)CHMe2 is also formed. Using Litmp in toluene the benzyl- and tolyboranes tmpB(R)CHMe2 are obtained. The (diphenylmethyl)boranes tmpB(Hal)CHPh2 react with Na(HBEt3) to produce tmpB(H)CHPh2, and substitution is also achieved with LiCMe3. While the 9-fluorenylboron fluoride tmpB(F)C13H9 is converted into tmpB(H)C13H9 by Na(HBEt3) the deep red tmpB(CMe3)C13H8Li (15) is formed in a 1:2 reaction with LiCMe3. 15 was characterized by its reaction products 13, 14 formed with HCl and CH3I, respectively. The formation of 15 is explained by a methyleneborane intermediate 2, resulting from dehydrofluorination of 11.
    Notes: Anstelle einer Dehydrohalogenierung erfolgt bei der Einwirkung von LiCMe3 auf tmpB(Hal)CHMe2 eine Substitution zu tmpB(CMe3)CHMe2 (tmp=2,2,6,6-Tetramethylpiperidino); in Gegenwart von Me2NCH2CH2NMe2 wird auch tmpB(NMe2)CHMe2 erhalten. Litmp in Toluol reagiert mit 3 zum Benzyl- bzw. Tolylboran tmpB(R)CHMe2. Die (Diphenylmethyl)borane tmpB(Hal)-CHPh2 setzen sich mit Na(HBEt3) zum Hydridoboran tmp B(H)CHPh2 um; mit LiCMe3 erfolgt ebenfalls Substitution. Das 9-Fluorenylborfluorid tmpB(F)C13H9 (11) wird von Na(HBEt3) nicht dehydrohalogeniert; man erhält das Hydrid 12. Mit LiCMe3 entsteht tiefrotes tmpB(CMe3)C13H8Li (15), das in die Derivate tmpB(CMe3)C13H9 (13) bzw. tmpB(CMe3)C13H8Me (14) überführbar ist. Die Bildung der Lithium-Verbindung wird über eine Methylenboran-Zwischenstufe 2 erklärt, die durch Dehydrofluorierung von 11 entsteht.
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    Enolether, XVIII Eine einfache Synthese von Cumarinen (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 373-378 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: In boiling 1,2-dichloroethane 3-ethoxyacryloyl chloride (1) reacts with phenols 2 to yield 3-ethoxyacrylates 3, which by treatment with conc. sulfuric acid/10% SO3 cyclize to give coumarins 9 in good yields. The methoxy-substituted compounds 3d and 3k do not react to coumarins 9 with H2SO4/SO3 but with POCl3/H2O at room temperature.
    Notes: Aus 3-Ethoxyacryloylchlorid (1) und Phenolen 2 entstehen in siedendem 1,2-Dichlorethan 3-Ethoxyacrylsäure-arylester 3, die sich mit konz. H2SO4/10% SO3 bei 0°C in guten Ausbeuten zu Cumarinen 9 cyclisieren lassen. Die 3-Ethoxyacrylsäure-methoxy-phenylester 3d und 3k cyclisieren unter diesen Bedingungen nicht, lassen sich jedoch mit POCl3/H2O bei Raumtemperatur ebenfalls in guten Ausbeuten in die entsprechenden Cumarine 9d und 9k überführen.
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    URL: http://dx.doi.org/10.1002/cber.19871200320
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    Halogen(halogenvinyl)carbene durch α-Eliminierung aus Oligohalogenpropenen und ihr intermolekularer Abfang: Ein neuer Weg zu (Halogenvinyl)cyclopropanen (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 395-400 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkyl- and alkoxy-substituted 1-fluoro-1-(trichlorovinyl)cyclo-propanes 6 were prepared by α-dehydrohalogenation of 1,1,2-trichloro-3,3-difluoro-1-propene (4) with lithium 2,2,6,6-tetramethylpiperidide (LiTMP) in the presence of olefins. 1,1,3,3-Tetrachloro-1-propene (7) reacts with lithium hexamethyldisilazide (LiHMDS) and olefins to give 1-chloro-1-(2,2-dichlorovinyl)cyclopropanes 8 with modest to good yields. The ethoxy-substituted vinylcyclopropane 8g is obtained by this method in 20-g amounts. The treatment of (E/Z)-1,2,3,3-tetrachloro-1-propene (10) with LiHMDS in 2,3-dimethyl-2-butene gives 1-chloro-1-[(Z)-1,2-dichlorovinyl]cyclopropane 11, and (dichloroethenylidene)cyclopropane 9 as a by-product.
    Notes: Durch α-Dehydrohalogenierung von 1,1,2-Trichlor-3,3-difluor-1-propen (4) mit Lithium-2,2,6,6-tetramethylpiperidid (LiTMP) in Gegenwart von Olefinen wurden mit Ausbeuten von 2-20% alkyl- und alkoxysubstituierte 1-Fluor-1-(trichlorvinyl)cyclopropane 6 dargestellt. 1,1,3,3-Tetrachlor-1-propen (7) reagiert mit Lithium-hexamethyldisilazid (LiHMDS) und Olefinen in mäßigen bis guten Ausbeuten zu 1-Chlor-1-(2,2-dichlorvinyl)cyclopropanen des Typs 8. Das ethoxysubstituierte Vinylcyclopropan 8g ist auf diese Weise im 20-g-Maßstab zugänglich. Die Behandlung von (E/Z)-1,2,3,3-Tetrachlor-1-propen (10) mit LiHMDS in 2,3-Dimethyl-2-buten liefert 1-Chlor-1-[(Z)-1,2-dichlorvinyl]cyclopropan 11 und (Dichlorethenyliden)cyclopropan 9 als Nebenprodukt.
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    Cycloadditionsreaktionen von Heterocumulenen, XXVIII Ein durch “no-bond”-Resonanz stabilisierter 1,6-Dipol. - Molekülstruktur und Reaktionsverhalten (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 405-410 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The X-ray structural investigation of the 1,6-dipole 1 reveals an intramolecular S-N contact of 236 pm, which indicates stabilization by no-bond resonance. In reactions with the heterocumulenes 2-5, the thiazoline ring of 1 is opened to give the heterocycles 7a-f, 8e. The reaction of bis(trimethylsilyl)thioketene (6) takes a deviating pathway: the primary adduct 15 gives a sigmatropic 1,3 shift of the dimethylamino group to yield product 16b. This constitution is derived from an X-ray structural study of the degradation product 17.
    Notes: Die Röntgenstrukturanalyse des 1,6-Dipols 1 zeigt einen intramolekularen S-N-Kontakt von 236 pm, der auf Stabilisierung durch „no-bond‘-Resonanz weist. In Umsetzungen mit den Heterocumulenen 2-5 wird der Thiazolin-Ring von 1 geöffnet; es resultieren die Heterocyclen 7a-f, 8e. Abweichend reagiert Bis-(trimethylsilyl)thioketen (6): das Primäraddukt 15 ergibt über eine 1,3-Verschiebung der Dimethylamino-Gruppe das Produkt 16b. Dessen Konstitution folgt aus der Röntgenstrukturanalyse des Abbauprodukts 17.
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    URL: http://dx.doi.org/10.1002/cber.19871200325
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    Zur Lewis-Acidität von Nickel(0), VI Dimethylmethylenoxosulfuran-Komplexe von Nickel(0) (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 425-427 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tris(ethene)nickel(0) reacts with dimethylmethyleneoxosulfurane, Me2(O)SCH2, in ether below 0°C to yield {Me2(O)SCH2}-Ni(C2H4)2 (1). At 0°C 1 decomposes violently to liberate ethene, cyclopropane, and methane. The reaction of 1 with CO at -78°C. The methylenesulfurane complexes are characterized by their IR and NMR spectra.
    Notes: Aus Tris(ethen)nickel(0) und Dimethylmethylenoxosulfuran, Me2-(O)SCH2, entsteht in Ether unterhalb 0°C {Me2(O)SCH2}-Ni(C2H4)2 (1). Bei 0°C zersetzt sich 1 explosionsartig unter Freisetzung von Ethen, Cyclopropan und Methan. Umsetzung von 1 mit CO bei -78°C führt zu {Me2(O)SCH2}Ni(CO)3 (2), das bis 20°C stabil ist. Die Methylensulfuran-Komplexe wurden durch ihre IR- und NMR-Spektren charakterisiert.
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    URL: http://dx.doi.org/10.1002/cber.19871200328
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    Beiträge zur Chemie des Phosphors, 173 Synthese und Eigenschaften der Diphosphiranimine (tBuP)2C=NR (R=2,4-tBu2C6H3, 2-tBuC6H4 (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 421-424 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The reaction of K(tBu)P-P(tBu)K with isocyanide dichlorides yields the first diphosphiranimines (tBuP)2C=NR. Besides, the cyclophosphanes (tBuP)n (n=3,4) and the two configurational isomers of the corresponding 1,3-diphosphetane-2,4-diimines are formed. N-Aryl-substituted diphosphiranimines with one bulky substituent in ortho-position to the imino function, such as (tBuP)2C=N(2,4-tBu2C6H3) (1) and (tBuP)2C=N(2-tBuC6H4) (2), are stable at room temperature and could be isolated in the pure state. The preparation of the isocyanide dichlorides 2,4-tBu2C6H3N=CCl2 and 2-tBuC6H4N=CCl2 is described.
    Notes: Die Reaktion von K(tBu)P-P(tBu)K mit Isocyanid-dichloriden führt zu den ersten Diphosphiraniminen (tBuP)2C=NR. Daneben entstehen die Cyclophosphane (tBuP)n (n=3,4) und die entsprechenden zwei konfigurationsisomeren 1,3-Diphosphetan-2,4-diimine. N-Arylsubstituierte Diphosphiranimine mit einem voluminösen Substituenten in ortho-Position zur Iminofunktion, wie (tBuP)2C=N(2,4-tBu2C6H3) (1) und (tBuP)2C=N(2-tBuC6H4) (2), sind bei Raumtemperatur beständig und konnten in reiner Form isoliert werden. Die Darstellung der Isocyanid-dichloride 2,4-tBu2C6H3N=CCl2 und 2-tBuC6H4N=CCl2 wird beschrieben.
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    Thiocarbonylfluoride im Solvenssystem Fluorwasserstoff: Generierung und Reaktionen von halogenierten Thiocarbenium-Ionen (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 429-433 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Solvolysis of thiocarbonyl fluorides 1b,c in HF/SbF5 or FSO3H/SbF5 yields dithietan-2-ylium ions 2b,c, respectively. Reactions of 2b,c with the base F⊖ in the solvent system HF give the dithietanes 3b,c. The acidity dependance of the formation of 2b,c is demonstrated by gradation of the acidic strength with NbF5 and F⊖. The existence of thioacylium ions 5b,c in solutions of extremely high acidity is concluded from NMR spectroscopic data. The results of the solvolysis reactions are confirmed by thioacylation of the aromatic compounds 6a-d in the HF system leading to trifluoromethyl dithiobenzoates 7a-d. Among the corresponding carbonyl fluorides only 4 exhibits comparable basic properties in superacids.
    Notes: Die Solvolyse der Thiocarbonylfluoride 1b,c in HF/SbF5 bzw. FSO3H/SbF5 führt zu den Dithietan-2-ylium-Ionen 2b,c. Umsetzungen von 2b,c mit der Base F⊖ im Solvenssystem HF liefern die Dithietane 3b,c. Die Aciditätsabhängigkeit der Bildung von 2b,c wird bei der Abstufung der Säurestärke mit NbF5 und F⊖ deutlich. NMR-Spektroskopische Daten lassen auf die Existenz der Thioacylium-Ionen 5b,c in Lösungen mit extrem hoher Acidität schließen. Thioacylierungen an den Aromaten 6a-d im HF-System bestätigen die Ergebnisse der Solvolysereaktionen und führen zur Darstellung der Dithiobenzoesäure-trifluormethylester 7a-d. Von den entsprechenden Carbonylfluoriden zeigt nur 4 ein vergleichbar basisches Verhalten in Supersäuren.
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    Hydrogenolyse kleiner Kohlenstoffringe, XVI Selektive katalytische Hydrierung von Dispiro[cyclopropan-1,3′-tricyclo[5.2.1.02,6]deca-4,8-dien-10′, 1″-cyclopropan] (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 439-441 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: In the title compound 7, obtainable by Diels-Alder dimerisation of spiro[2.4]hepta-4,6-diene (1), the conjugated cyclopropane ring is opened to form an ethyl substituent on hydrogenation with Pd/C. The second cyclopropane ring provides the geminal methyl groups in the exo-endo-product mixture 11. With other catalysts (Pd/C) substantial amounts of compound 13 are obtained, the double bonds of 7 being hydrogenated only. With PtO2 in acetic acid 13 gives rise to the tetramethyl derivative 16.
    Notes: Bei der Hydrierung der durch Diels-Alder-Dimerisierung von Spiro[2.4]hepta-4,6-dien (1) zugänglichen Titelverbindung 7 über Pd/C wird der konjugierte Dreiring zur Ethylgruppe geöffnet, und der andere liefert die geminalen Dimethylgruppen in exo-endo-Produktgemisch 11. Mit anderen Katalysatoren (Pt/C) gelingt es, daneben erhebliche Mengen des nur an den Doppelbindungen hydrierten Produktes 13 abzufangen und daraus mit PtO2 in Eisessig die Tetramethylverbindung 16 zu erhalten.
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    Selektivitätsstudien bei Festkörperphotolysen von 2,5-Bis(methylen)cyclopentanonen (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 387-393 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: While the photolysis of crystalline trans,trans-2,5-dibenzylidenecyclopentanone (1, Ar=C6H5) yields three dimers in a latticecontrolled manner, the crystals of its symmetric derivatives 1 are photostable. The 2-alkylidene-5-arylidenecyclopentanones 4 and 5 yield selectively 6 or 8 (centrosymmetric) and oligomers. 4b gives 6 and 7. The 4-nitrophenyl and 4-pyridinyl substituents prove to be particularly effective in terms of the socalled crystal engineering due to their electrostatic effects. The occurance of oligomers shows that the unsymmetric derivatives 4 and 5 do not always react in a single topochemical way.
    Notes: Während die Kristallphotolyse von trans-2,5-Dibenzyliden-cyclopentanon (1, Ar=C6H5) gitterkontrolliert drei Dimere liefert, sind dessen kristalline symmetrische Derivate 1 photostabil. Die 2-Alkyliden-5-arylidencyclopentanone 4, 5 liefern neben Oligomeren selektiv 6 oder 8 (zentrosymmetrisch). Aus 4b entsteht neben 6 auch 7. 4-Nitrophenyl- und 4-Pyridinylgruppen erweisen sich wegen ihrer elektrostatischen Effekte als besonders wirksam im Hinblick auf die gezielte Kristallgestaltung. Die Oligomerenbildung zeigt, daß nicht alle unsymmetrischen Derivate 4, 5 topochemisch einheitlich reagieren.
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    Diagnostic OH 1H-NMR shift differences in syn and anti ß-Hydroxy Ethers (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 331-333 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Die relative chemische Verschiebung des OH-Protonen-Signals in den 1H-NMR-Spektren eines Paares diastereomerer ß-Hydroxyether erlaubt eine syn/anti-Zuordnung der relativen Konfiguration. Dies basiert vermutlich auf der Bildung von Strukturen mit intramolekularer Wasserstoff-Brücke. Insofern ist diese Regel auf solche ß-Hydroxyether beschränkt, bei denen nur dieser Typ von intramolekularer H-Brücke ausgebildet werden kann.
    Notes: In a pair of diastereomeric ß-hydroxy ethers the relative 1H-NMR chemical shift of the OH proton is diagnostic for the syn or anti stereostructure. This is probably based on the presence of internally hydrogen-bonded structures. The rule is therefore restricted to those compounds for which only this type of internal hydrogen bonding is accessible.
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    Das Hydrolyseverhalten zwei- und dreifach mesylierter Hydroxylamine und ihrer Derivate (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 351-354 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The mesylhydroxylamines (CH3SO2)2NOH, (CH3SO2)2NOCH3, CH3SO2N(H)OSO2CH3, CH3SO2N(CH3)OSO2CH3 (1-4) and (CH3SO2)2NOSO2CH3 (5) were treated with basic, neutral, and acidic aqueous solutions. The reaction products were identified. Possible decomposition mechanisms were discussed.
    Notes: Die Mesylhydroxylamine (CH3SO2)2NOH, (CH3SO2)2NOCH3, CH3SO2N(H)OSO2CH3, CH3SO2N(CH3)OSO2CH3 (1-4) und (CH3SO2)2NOSO2CH3 (5) wurden in alkalischer, neutraler und saurer Lösung hydrolysiert. Die Zersetzungsprodukte wurden identifiziert und mögliche Reaktionswege ihrer Entstehung diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19871200317
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    Gas/liquid interfacial area per unit volume and volumetric mass transfer coefficient in stirred slurry reactors (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 204-215 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In three-phase systems, where the liquid constitutes the continuous phase, solid is the catalyst and gas represents the dispersed phase, there are decisive criteria which have to be observed in reactor design. These are e.g. the interfacial area per unit volume between gas and liquid, the volumetric mass transfer coefficient and the mass transfer coefficient. The basic aim of the present work was therefore the investigation of these parameters in relation to the main influencing parameters. Process parameters stirrer speed and superficial gas velocity were varied as well as the physical properties such as liquid viscosity, solids concentration, particle diameter and a geometrical parameter, i.e. reactor diameter. The sulphite method was employed for the determination of these values. The test results confirmed the known relationships of power consumption and superficial gas velocity. An increase in the liquid viscosity leads to a decrease in all the tested values. In most cases, suspended solid particles lead to a lowering of the test values. The influence of the tank diameter on the plots of the test values against specific power consumption turned out to be invariant so that a scale-up of geometrically similar systems can be carried out at constant power consumption, superficial gas velocity and liquid viscosity.
    Additional Material: 27 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100125
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    Desorption delay in gas/liquid systems during vessel top ventingLecture at the European Two-Phase Flow Group Meeting, München, June 10 to 13, 1986.Dedicated to Prof. Dr. rer. nat. Heinz Harnisch on occasion of his 60th birthday (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 217-224 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: During the sudden unheated vessel top venting of initially saturated two-component gas/liquid mixtures, in which the gas is also extensively dissolved in the non-evaporating liquid phase, a solubility inequilibrium develops between the phases; re-equilibration can set in only after a so-called desorption delay time. Laboratory measurements of this delay time were under-taken with model mixtures of CO2 and water and viscous aqueous (Newtonian) solutions by high speed cinematography. The parameters of the experiments are relief cross-section, initial liquid level, pressure, temperature, and concentration. The shortest deley time obtained lasts approximately 75 ms. It differs substantially from the minimum boiling delay time previously measured with various refrigerants in the same test facility. The experimental results are correlated by a semi-empirical dimensionless power relationship, which includes all independent primary design variables generally availble in a physically consistent interrelationship. Reasonable extrapolations to other test conditions and aqueous two-component systems with an acceptable accuracy systems can therefore be expected.
    Additional Material: 10 Ill.
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    A differential model for a countercurrent extractor column with non-constant flow rates, interfacial area per unit volume and axial dispersion coefficients (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 375-382 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the extraction literature, no attention has been given so far to differential calculation models for countercurrent extraction columns which take into account the changes in flow rates of the phases as a result of transferred mass, and which also reflect the variations in interfacial area per unit volume and in axial dispersion coefficients since these depend on the flow rates. The present contribution puts forward a formulation of such a model; this results in a set of non-linear differential equations with separated boundary conditions, representing the feeds at either side of the extraction column. This set of differential equations must be solved numerically. The model is illustrated by a sample calculation on the extraction of benzene with furfural. In this (realistic) example, the interfacial area per unit volume varies from bottom to top by a factor of 3. Ignoring this effect would obviously result in serious under- or overdesign.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100146
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    Vapour-liquid and vapour-liquid-liquid equilibria in ternary and quaternary systems of n-hexadecane, benzene, water and hydrogen, at elevated temperatures and pressures (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 382-389 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Phase equilibria in the n-hexadecane-water-hydrogen and n-hexadecane-benzene-water-hydrogen systems were determined experimentally at temperatures between 200 and 350°C and pressures between 100 and 300 bar. At high water concentrations, three-phase equilibria were observed. Two-phase regions could be correlated with a modified Redlich-Kwong equation of state. The influence of interaction parameters on the calculated miscibility gaps was investigated. On application of mean interaction parameters, it is possible to calculate phase equilibria at different pressures or temperatures with the same set of parameters. In the ternary system, the three-phase regions could be calculated from the correlated binodal curves of two-phase regions. In the quaternary system, cross-sections through the vapour-liquid miscibility gap could be successfully correlated.
    Additional Material: 11 Ill.
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    Oxygen and methane enrichment  -  a comprison of module arrangements in gas permeation (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 256-261 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the separation of gaseous mixtures by gas permeation, it is in some cases impossible to achieve the desired product quality in a single stage and, therefore, several stages may be necessary. Multistage processes can be implemented by membrane modules arranged in the form of a cascade or by a membrane column design. On the basis of an economic analysis, this paper discusses different possible module arrangements for 2 cases, i.e. the enrichment of oxygen from air and the separation of methane from biogas. Present calculations indicate that, in the first case, two-stage cascades with or without recycle and, in the second case, one-stage cascade without recycle constitute the optimum module arrangements. However, depending on the selling price of the methane enriched gas, one- or two-stage cascades with recycle have to be considered. Finally, It was shown that, in the permeation of non-ideal gases, the Joule-Thomson effect has to be taken into account.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100131
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    Homogeneous non-equilibrium two-phase critical flow modelPresented by J.J. Schröder at the “Jahrestreffen der Verfahrens-Ingenieure”, Strasbourg, September 17 to 19, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 420-426 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An important aspect of nuclear and chemical reactor safety is the ability to predict the maximum or critical mass flow rate from a break or leak in a pipe system. At the beginning of such a blowdown, if the stagnation condition of the fluid is subcooled or slightly saturated thermodynamic non-equilibrium exists in the downstream, e.g. the fluid becomes superheated to a degree determined by the liquid pressure. A simplified non-equilibrium model, explained in this report, is valid for rapidly decreasing pressure along the flow path. It presumes that fluid has to be superheated by an amount governed by physical principles before it starts to flash into steam. The flow is assumed to be homogeneous, i.e. the steam and liquid velocities are equal. An adiabatic flow calculation mode (Fanno lines) is employed to evaluate the critical flow rate for long pipes. The model is found to satisfactorily describe critical flow tests. Good agreement is obtained with the large scale Marviken tests as well as with small scale experiments.
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    URL: http://dx.doi.org/10.1002/ceat.270100152
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    Progress in the kinetics of coal and char gasificationDedicated to Professor Dr. Kurt Hedden on the occasion of his sixtieth birthday (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 411-419 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This contribution reviews the work performed mainly at Bergbau-Forschung during the past few years. First, it deals with the quantitative description of gasification kinetics, taking into account the pressure of the gasifying agent and partial pressures of product gases. Thereby, a method and quantitative data are provided for the calculation of reaction rates for uncatalyzed and potassium-catalyzed gasification, on the example of chars from high volatile bituminous coals. In addition, a method for characterization of internal surface area by oxygen chemisorption with respect to char reactivity has been improved. Progress has also been achieved in the assessment of the impact of pyrolysis conditions, especially the time-temperature profile during char formation, on its chemical activity during subsequent use.
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    URL: http://dx.doi.org/10.1002/ceat.270100151
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    Chemical technology of natural gas - its present state and prospects (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 297-305 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Against the background of long-term availability of natural gas, its present technology and future prospects are described. Particular emphasis is put on the oxidative coupling of methane to C2+ hydrocarbons: (1) Catalyst development, activity, selectivity and deactivation as well as reactor operation are discussed; (2) a tentative process scheme is put forward and its economics evaluated with respect to ethylene production.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100136
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    Conversion of organic oxygen compounds and their mixtures on H-ZSM-5 (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 323-329 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The conversion of a number of alcohols, ethers, ketones, aldehydes, carboxylic acids, esters, and cyclic compounds and their mixtures on H-ZSM-5 at 673 K was investigated. These compounds can be easily converted to aromatic hydrocarbons if the C/H ratio of the molecule fragment, remaining after elimination of oxygen as water, is less than 0.62. At higher C/H ratios, coking of the catalyst increases, thus reducing its lifetime, a difficulty which can be overcome by hydrogenation of these compounds prior to their conversion over H-ZSM-5. A procedure is proposed for converting at least a part of organic waste chemicals to valuable products instead of burning them.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100139
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    Flow-induced vibrations of tube arrays in cross-flow (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 312-322 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Existing heat exchanger design criteria do not satisfy the continually increasing requirements for greater efficiency or mass flux and energy throughput. Occasionally, failures appear even after only a few hours of operation, as shown in section 3. A long series of experiments, often carried out on original scale, did lead to the derivation of a large number of empirical expressions; however, physical explanations of the complex tube-failure interactions could not as yet be found. In contrast, experiments with a well defined simple model, whereby the tube deflections were recorded digitally and, at the same time, tube-fluid interactions were registered on a high-speed film, show that elementary “fluid transport mechanisms” control the stability behaviour of the heat exchanger tubes. Vibration excitation mechanisms such as “galloping”, “jet switching” and “whirling” (fluid elastic coupling) proved, with their characteristics, as typical for the vibration behaviour of single rows within the tube array, but not for the vibration phenomena of tube bundles.
    Additional Material: 17 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100138
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    Rheology and flow of phosphate slurries (mine tailings) in pipesPresented by O. Scrivener at the “Jahrestreffen der Verfahrens-Ingenieure”, Strasbourg, September 17 to 19, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 305-311 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An experimental study of the flow of phosphate mine tailings was carried out in order to characterize these suspensions of fine particles for pipeline transport. Rheological measurements with a rotating cylinder viscometer indicate a viscoplastic behaviour which can be represented by a Herschell-Bulkley or by a Casson model. The variation of the parameters of these models with solids concentration reveals a change in the behaviour at a concentration of 10 to 15%. The pressure drops were measured during flow in capillary tubes, in both laminar and turbulent regimes. The variation of the pressure drop coefficient (Fanning friction factor) as a function of the generalized Reynolds number confirms the validity of the employed rheological models. The results are in good agreement with measurements made in pipes of industrial size. The velocity profiles measured with a novel ultrasonic velocimeter demonstrate the influence of the rheological behaviour on the yield and wall stresses.
    Additional Material: 10 Ill.
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    Comparison of performance of an industrial VGO-treater with reactor model predictions (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 349-352 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A simplified reactor model can be used for predicting the performance of an industrial VGO-treater. Laboratory-scale experiments performed on the same feed and catalyst as those in the industrial unit lead to a reactor simulation which agrees well with the data from this unit. In the laboratory experiments, it is possible to overcome the specific hydrodynamic problems of tricklebed reactors by appllying the catalyst dilution technique. Results obtained by this technique allowed the development of a reactor model which enables the user to simulate the adiabatic behaviour of the industrial reactor. In this way, the significant gap between the reaction temperature in the isothermal laboratory reactor and the WABT of the industrial adiabatic reactor can be bridged.
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    URL: http://dx.doi.org/10.1002/ceat.270100142
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    Reaktion von Acetamidin mit Kohlenstoffdisulfid 6. Methylierung von N-Acetimidoyldithiocarbamaten (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 125-133 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Chalcogenolates. 177. Reaction of Acetamidine with Carbon Disulfide. 6. Methylation of N-Acetimidoyl DithiocarbamatesN-Acetimidoyl dithiocarbamates react with methyl iodide to produce the hitherto unknown methyl ester of N-acetimidoyl dithiocarbamic acid AIDTC-CH3 in low yield as well as the S,S′-dimethyl ester of trithiocarbonic acid TTK-(CH3)2, the S-methyl ester of dithiocarbamic acid DTC-CH3, and 2-thiomethyl-4, 6-dimethyl-1, 3, 5-triazine TMMT besides other products (formulae see “Inhaltsübersicht”).The compounds have been characterized by means of diverse methods.
    Notes: Die Umsetzung von N-Acetimidoyldithiocarbamaten mit Methyliodid liefert den bisher nicht bekannten N-Acetimidoyldithiocarbamidsäure-S-methylester AIDTC-CH3 in nur geringer Ausbeute und den S,S′-Dimethylester der Trithiokohlensäure TTK-(CH3)2, den S-Methylester der Dithiocarbamidsäure DTC-CH3 sowie 2-Thiomethyl-4, 6-dimethyl-1, 3, 5-triazin TMMT neben anderen Reaktionsprodukten: Die Verbindungen wurden mit verschiedenen Methoden charakterisiert.
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    URL: http://dx.doi.org/10.1002/zaac.19875450214
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    Umsetzungen von Tetrafluor-1,2-ethandisulfenyldichlorid mit Ketonen und Olefinen (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 143-147 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Tetrafluoro-1, 2-ethanedisulfenyldichloride with Ketones and OlefinesThe reaction of ClSCF2CF2SCl 1 with (CH3)3C—C(O)CH3, hexene, diacetyl, cyclobutanone, and H2C=CHC(O)CH3 leads to the cyclic and acyclic products 2-6. They are destillable liquids, which have been characterized on the basis of elemental analysis, mass spectra, 19F-, 13C-, and 1H-n.m.r. spectra. The reaction mechanism will be discussed.
    Notes: Die Reaktion von ClSCF2CF2SCl 1 mit (CH3)3C—C(O)CH3, Hexen, Diacetyl, Cyclobutanon und H2C=CHC(O)CH3 führt zu den cyclischen und acyclischen Substitutionsprodukten 2-6. Es sind destillierbare Flüssigkeiten, die anhand von Elementaranalysen, Massenspektren, 19F-, 13C- und 1H-NMR-Spektren charakterisiert wurden. Der Reaktionsmechanismus wird diskutiert.
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    URL: http://dx.doi.org/10.1002/zaac.19875450216
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    Magnetische Eigenschaften von Ti3-xMxO5-Phasen (M = V3+, Cr3+, Nb4+) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 134-142 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Magnetic Properties of Ti3-xMxO5 Phases (M = V3+, Cr3+, Nb4+)The magnetic properties of Ti3-xVxO5, Ti3-xCrxO5, and Ti3-xNbxO5 phases are reported. In the case of V3+ and Cr3+ the magnetic leaping-temperature decreases, however Nb4+ shift the phase-transition towards higher temperatures. All samples show a “memory-effect” in magnetic properties, i. e. the results of heating- and cooling-cycles are higher susceptibilities of the α-phase of Ti3O5. Endowed Ti3O5 phases show for the α- and β-Ti3-xMxO5 til the leap Curie-Weiss characteristic in 1/X vs. temperature measurements. Exception is β-Ti3-xNbxO5, its susceptibility is independend of the temperature up to x ≤ 0.3.
    Notes: Es wird über die magnetischen Eigenschaften von Ti3-xVxO5, Ti3-xCrxO5 und Ti3-xNbxO5 berichtet. Für V3+ und Cr3+ verschiebt sich die magnetische Sprungtemperatur zu kleineren Werten, Nb4+ dagegen verlagert den Phasenübergang in Richtung höherer Temperaturen. Alle Präparate zeigen einen “Gedächtniseffekt” im magnetischen Verhalten, d.h. Aufheiz- und Abkühlzyklen führen zu höheren Suszeptibilitätswerten der α-Form von Ti3O5. Dotiertes Ti3O5 zeigt für α- und β-Ti3-xMxO5 bis zum Sprung in den 1/X über T-Kurven Curie-Weiss-Verhalten. Ausnahme ist β-Ti3-xNbxO5, dessen Molsuszeptibilität bis x ≤ 0,3 temperaturunabhängig ist.
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    Neue Oxoborate der Alkalimetalle: NaLi2[BO3] [1] (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 157-168 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Borates of the Alkali Metals: NaLi2[BO3]The hitherto unknown NaLi2[BO]3 is prepared in the shape of monoclinic, colourless-transparent and prismatic single crystals [a = 950.7(4) pm, b = 1 203.7(4) pm, c = 493.0(3) pm, β = 104.0(10)°, dx = 2.32 g/cm3, dpyk = 2.28 g/cm3]. The crystal structure has been solved by four-circle-diffractometer [PW 1100, MoKα-, R = 7.52%, Rw = 4.66%].Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated.
    Notes: Neu dargestellt wurde NaLi2[BO3] in Form monokliner, farblos-durchsichtiger, prismatischer Einkristalle. [a = 950, 7(4) pm, b = 1 203, 7(4) pm, c = 493, 0(3) pm, β = 104, 0(10)°, Z = 8, dx = 2, 32 g/cm3, dpyk = 2, 28 g/cm3]. Die Kristallstruktur wurde über Vierkreisdiffraktometerdaten [PW 1100, MoKα-, R = 7, 52%, Rw = 4, 66%, für 1 293 von 1 591 Io(hkl)] aufgeklärt. NaLi2[BO3] ist gegenüber Luftfeuchtigkeit empfindlich.Effektive Koordinationszahlen, ECoN, diese über Mittlere Fiktive Ionenradien, MEFIR, werden berechnet.
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    URL: http://dx.doi.org/10.1002/zaac.19875450218
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    Kristallstrukturen und Phasentransformationen von Caesiumtrihalogenogermanaten(II) CsGeX3 (X = Cl, Br, I) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 148-156 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structures and Phase Transformations of Cesium Trihalogenogermanates CsGeX3(X = Cl, Br, I)The compounds CsGeX3 (X = Cl, Br, I) have been obtained by reactions of Ge(OH)2 with CsX in aquaeous HX solutions. The thermal behavior has been studied by X-ray diffraction. Raman spectroscopy, and DTA/DSC. The compounds are dimorph. The low temperature modifications L-CsGeX3 show a rhomboedric deformed perovskite type structure. The high temperature phases H-CsGeX3 form the cubic perovskite type structure. The reversible phase transitions are interpreted as a result of position changes of the Ge atoms in the H-forms (Order-Disorder transitions). The transition temperatures increase in the sequence CsGeCl3 (155°C), CsGeBr3 (238°C), CsGeI3 (277°C).
    Notes: Das thermische Verhalten der Verbindungen CsGeX3 (X = Cl, Br, I), durch Umsetzungen von Ge(OH)2 mit CsX in wäßrigen HX-Lösungen erhalten, wurde unter Verwendung von Röntgenbeugung, Ramanspektroskopie und DTA/DSC untersucht. Die Verbindungen sind dimorph. Bei den Tieftemperaturmodifikationen L-CsGeX3 werden rhomboedrische Verzerrungsvarianten der Perowskitstruktur (Raumgruppe R3m), bei den Hochtemperaturformen H-CsGeX3 die kubische Perowskitstruktur gefunden. Die reversiblen Phasentransformationen werden als Ordnungs-Unordnungs-Übergänge infolge von Platzwechselvorgängen der Ge-Atome bei den H-Formen gedeutet. Die Umwandlungstemperaturen steigen in der Reihe CsGeCl3 (155°C), CsGeBr3 (238°C), CsGeI3 (277°C) an.
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    URL: http://dx.doi.org/10.1002/zaac.19875450217
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    Darstellung und Kristallstruktur der Calciumnitridhalogenide Ca2NCl und Ca2NBr (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 177-183 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of the Calcium Nitride Halides Ca2NCl and Ca2NBrCa2NCl and Ca2NBr were prepared as well crystalline powders of light-grey colour by reaction of Ca3N2 and CaX2 in a molar ratio 1:1 in steel ampoules under argon (50 h 740°C; 15 h 1 000°C and 40 h 950°C, resp.). Brownish transparent single crystals were obtained by annealing specimens in molybdenum ampoules (25 d 1 125°C).The compounds crystallize in the anti-α-NaFeO2-structure (Crystallographic data: see “Inhaltsübersicht”). N3- and X- are rhombohedrally distorted cubic close packed. The sequence of the anionic layers is X-—N3-—X-—N3-—…. Ca2+ is shifted towards N3- so that Ca2N+ layers are formed which are held together by the halide ions.
    Notes: Ca2NCl und Ca2NBr wurden als hellgraue, sehr gut kristalline Pulver aus Ca3N2 und CaX2 im Molverhältnis 1:1 in Stahlampullen unter Argon dargestellt (50 h 740°C, 15 h 1 000°C bzw. 40 h 950°C). Bräunlich transparente Einkristalle erhielt man durch 25tägiges Tempern der Präparate in Molybdänampullen bei 1 125°C.Die Verbindungen kristallisieren im Anti-α-NaFeO2-Typ (R3m, Ca2NCl: a = 366,61(2) pm, c = 1971,1(4) pm, c/a = 5,377(2), Z = 3, drö = 2,815 g · cm-3, d425 = 2,77; Ca2NBr: a = 371, 66(3) pm, c = 2055, 8(4) pm, c/a = 5, 531(2), drö = 3,526 g · cm-3, d425 = 3,51). N3- und X- bilden zusammen eine rhomboedrisch verzerrte kubisch dichteste Anionenpackung mit der Schichtabfolge X-—N3-—X-—N3-—…. Ca2+ ist auf N3- zugerückt, wodurch Ca2N+-Schichtpakete entstehen, die durch X- zusammengehalten werden.
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    Tribrom-methylnitren-Komplexe des Wolframs Die Kristallstruktur von PPh3Me[WBr5(NCBr3)] (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 169-176 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tribromomethylnitrene Complexes of Tungsten. Crystal Structure of PPh3Me[WBr5(NCBr3)]Tungsten hexabromide reacts with BrCN in boiling bromine under formation of the BrCN adduct of tribromomethylnitrene tungsten, [BrCN—WBr4(NCBr3)]. This reacts with triphenylmethylphosphonium bromide in dibromomethane forming the tribromomethylnitrene pentabromowolframate, PPh3Me[WBr5(NCBr3)]. Both compounds form brown-black, moisture sensitive crystal powders that were characterized by their IR spectra. The crystal structure of PPh3Me[WBr5(NCBr3)] was determined by X-ray diffraction (3 664 observed reflexions, R = 0.066). Crystal data: a = 1 401.6, b = 1 243.3, c = 884.6 pm, α = 90.82, β = 110.74, γ = 90.67°, space group P1, Z = 2. The compound consists of PPh3Me⊕ cations and [WBr5(NCBr3)]⊖ anions in which the tungsten atoms have a distorted octahedral coordination by five bromine atoms and the N atom of the nitrene ligand. The WN bond length of the nitrene ligand (175 pm) corresponds approximately to a triple bond; the W≡N—C group is linear and shows a strong trans effect.
    Notes: Wolframhexabromid reagiert mit Bromcyan in siedendem Brom unter Bildung des Bromcyanadduktes von Tribrommethylnitren-tetrabromowolfram, [BrCN—WBr4(NCBr3)], das sich mit Triphenylmethylphosphoniumbromid in Dibrommethan zu Tribrommethylnitren-pentabromowolframat, PPh3Me[WBr5(NCBr3)], umsetzt. Beide Verbindungen sind schwarzbraune, feuchtigkeitsempfindliche Kristallpulver, die durch ihre IR-Spektren charakterisiert werden. Die Kristallstrukturanalyse von PPh3Me[WBr5(NCBr3)] wurde mit Röntgenbeugung ausgeführt, Raumgruppe P1, Z = 2, 3664 unabhängige, beobachtete Reflexe, R = 6, 6%. Die Gitterkonstanten sind a = 1401, 6; b = 1 243, 3; c = 884, 6 pm; α = 90,82°, β = 110,74°; γ = 90,67°. Die Verbindung besteht aus PPh3Me⊕-Ionen und Anionen [WBr5(NCBr3)]⊖, in denen das Wolframatom verzerrt oktaedrisch von fünf Bromatomen und dem N-Atom des Nitrenoliganden umgeben ist. Der WN-Abstand entspricht mit 175 pm etwa einer Dreifachbindung; die Gruppe \documentclass{article}\pagestyle{empty}\begin{document}$\mathop {\rm W}\limits^ \odot \equiv \mathop {\rm N}\limits^ \oplus - {\rm CBr}_3$\end{document} weist eine gestreckte WNC-Achse auf (178°), sie verursacht einen starken trans-Effekt.
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    Dimethylaminophosphoniumsalze (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 184-190 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimethylaminophosphonium SaltsThe amides and chlorides of phosphoric acid 1 and 2 react with N-chlor-dimethylamine or chlorine, respectively, to dimethylaminophosphonium salts 3 and 4. Phosphor trichloride and N-chlor-dimethylamine as well as dimethylamino-dichloro-phosphine and chlorine react to bis(dimethylamino)-dichloro-phosphonium hexachlorophosphate 7.
    Notes: Aus Phosphorigsäureamiden und -chloriden wurden durch Reaktion mit N-Chlordimethylamin bzw. Chlor die Dimethylaminophosphoniumsalze 3 und 4 dargestellt. Die Reaktion von Phosphortrichlorid mit N-Chlordimethylamin bzw. von Dimethylamino-dichlorphosphin mit Chlor führte zum Bis(dimethylamino)dichlorphosphonium-hexachlorophosphat 7.
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    Calcium-diazido-di-dimethylformamid, Ca(N3)2[OCHN(CH3)2]2 Darstellung und Kristallstruktur (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 191-196 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Calcium-diazido-di-dimethylformamide, Ca(N3)2[OCHN(CH3)2]2, Preparation and Crystal StructureThe title compound was prepared by the reaction of Ca(N3)2 with OCHN(CH3)2 in aqueous solution. The crystals are orthorhombic, a = 968.5(3), b = 1 479.6(15), c = 1 945.3(17) pm, space group Cmca, Z = 8. The crystal structure was determined by single crystal X-ray diffraction techniques and refined to R = 0.061. Calcium atoms are surrounded by four terminal nitrogen atoms of azide groups and by two oxygen atoms of dimethylformamide (DMF). The polyhedra around Ca are octahedra which are linked via four azide groups to form Ca(N3)2 layers. The DMF molecules are located between these layers, and they are highly disordered.
    Notes: Die im Titel angegebene Verbindung wurde durch Reaktion von Ca(N3) mit Dimethylformamid in wäßriger Lösung hergestellt. Die Kristalle sind rhombisch, a = 968, 5(3), b = 1 479, 6(15), c = 1 945, 3(17) pm, Raumgruppe Cmca, N = 8. Die Kristallstruktur wurde mittels Röntgen-Einkristallmethoden bestimmt und zu R = 0, 061 verfeinert. Die Calciumatome werden oktaedrisch von vier Endstickstoffatomen der Azidgruppen und von zwei Sauerstoffatomen des Dimethylformamids (DMF) umgeben. Die Oktaeder sind über vier Azidgruppen zu Ca(N3)2-Schichten verknüpft. Die DMF-Moleküle befinden sich zwischen den Schichten und sind stark fehlgeordnet.
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    The System Ga2S3—Pr2O3 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 197-201 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Das System Ga2S3—Pr2O3Das Zustandsdiagramm des Ga2S3—Pr2O3-Systems wird mittels DTA, HT-DTA, Röntgenphasen-, Mikrostruktur- und thermodynamischer Analysen sowie durch Bestimmung der Mikrohärte untersucht. Das System ist eutektisch, die Löslichkeit auf der Seite des Ga2S3 beträgt 8 Mol.-% bei 295 K. Im System wird die Existenz einer inkongruent schmelzenden Verbindung von Ga2S3 · 2 Pr2O3 gefunden.
    Notes: The diagram of state of Ga2S3—Pr2O3 has been investigated by the methods of differential thermal, high-temperature differential thermal, X-ray diffraction, microstructural and thermodynamic analyses and by measurement of microhardness of the samples. It has been found that the system is eutectic, the solubility on the part of Ga2S3 at 295 K reaches 8 mol.%. In the system the existence of one incongruently-melting compound of Ga2S3 · 2 Pr2O3 was found.
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    Massenspektroskopische Untersuchung der Borfluorid-Komplexe ABF4 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 224-226 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mass Spectroscopic Investigation of Boron Fluoride Complexes ABF4The complexes ABF4, which on heating are decomposed after ABF4,s,l = AF,s + BF3 (A = Li—Cs), besides this reaction also evolve A2(BF4)2 molecules (A = K, Rb, Cs). The appearance potentials have been determined.
    Notes: Die Komplexe ABF4, die sich beim Erhitzen nach ABF4,f,fl = AF,f + BF3 (A = Li—Cs) zersetzen, geben neben BF3 auch A2(BF4)2-Moleküle (A = K, Rb, Cs) an die Gasphase ab. Auftrittspotentiale wurden bestimmt.
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    Masthead (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987) 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    URL: http://dx.doi.org/10.1002/zaac.19875460301
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    Thermogravimetrische Untersuchungen an Vanadium-komplexen (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 235-240 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermogravimetric Investigations of Vanadium ComplexesExtensive studies on oxovanadium(IV) and (V) complexes with bidentate chelating ligands include thermogravimetric investigations. TG, DTG, and DTA data provide additional facts to redox behaviour and stability of the complexes. These data also allow a critical appreciation of the given melting temperatures.
    Notes: Im Rahmen grundlegender Untersuchungen zu Oxovanadium(IV)- bzw. (V)-Komplexen mit zweizähnigen Chelatbildnern werden aus den TG-, DTG- und DTA-Kurven ausgewählter Chelate zusätzliche Daten zum Redoxverhalten und zur Stabilität der Komplexe gewonnen. Die Thermogramme gestatten eine kritische Wertung gemessener Schmelzpunkte.
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    Verdrillte Tetraederketten ∞1[Li(NH2)4/2-] in der Struktur der hexagonalen Modifikation von Caesiumlithiumamid, CsLi(NH2)2 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 48-54 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Twisted Tetrahedra Chains ∞1[Li(NH2)4/2-] in the Structure of the Hexagonal Modification of Cesium Lithium Amide, CsLi(NH2)2The ternary amides, CsLi(NH2)2 (dimorphous) and CsLi2(NH2)3, were prepared by reaction of the metals with ammonia in high pressure autoclaves. The structure of the hexagonal modification of CsLi(NH2)2 was established inclusive the hydrogen atom positions from single crystal x-ray data. The compound crystallizes in the space group P6222 with N = 3. The lattice parameters are a = 6.331(1) Å and c = 8.410(1) Å.Lithium ions occupy distorted nitrogen tetrahedra. These tetrahedra are connected by translocated edges along [001]. The cesium ions combine the equally oriented chains ∞1[Li(NH2)4/2-]. The amide ions are twisted out of the hexagonal aa-plane. If we assume sp3-hybridized valence electrons of the nitrogen atoms the bonding interaction between free electron pairs and lithium ions are thereby strenghtened.
    Notes: Ternäre Amide im System CsNH2/LiNH2—CsLi(NH2)2 (dimorph) und CsLi2(NH2)3 - wurden durch Umsetzung der Metalle mit NH3 in Hochdruckautoklaven dargestellt.Die Struktur der hexagonalen Form von CsLi(NH2)2 wurde aus Röntgenbeugungsintensitäten eines Einkristalls einschließlich der H-Atom-Lagen bestimmt. Die Verbindung kristallisiert in der Raumgruppe P6222 mit Z = 3 und den Gitterkonstanten a = 6,331(1) Å und c = 8,410(1) Å.Die Lithiumionen befinden sich in verzerrten Stickstofftetraedern. Diese bilden über transständige Kanten längs [001] Ketten. Die Caesiumionen verknüpfen die gleichsinnig orientierten Ketten ∞1[Li(NH2)4/2-]. Die Amidionen sind aus der hexagonalen aa-Ebene gedreht. Bei einer sp3-Hybridisierung der Valenzelektronen der Stickstoffatome wird dadurch die Wechselwirkung zwischen freien Elektronenpaaren und den Lithiumionen begünstigt.
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    Dimethyl-N-Halogenamine, ihre Ammoniumsalze und Bortrihalogenid-Addukte (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 99-106 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimethyl-N-Halogenoamine, their Ammonium Salts and Borontrihalide AdductsThe preparation and vibrational spectra of (CH3)2NHCl+X- (X- = CF3SO3- I, SO3F- II, SO3Cl- III, BCl4- IV), and (CH3)2NHBr+CF3SO3- V as well as the adducts (CH3)2NCl · S (S = BF3 VI, BCl3 VII, BBr3 VIII) and (CH3)2NBr · BF3 IX are reported.The crystal structure of VII has been determined from three-dimensional diffractometer data at -100°C. The Cl atom and one methyl group in the dimethyl-N-chloroamino group show disorder. The structural data are: B—Cl 183(2) pm, B—N 167(3) pm, N—C 152(3) pm (distances to disordered positions are not included).
    Notes: Es wird über Darstellung und Schwingungsspektren der Dimethylammoniumsalze (CH3)2NHCl+X- (X- = CF3SO3- I, SO3F- II, SO3Cl- III, BCl4- IV) und (CH3)2NHBr+CF3SO3- V sowie über die Lewis-Säure-Base-Addukte (CH3)2NCl · S (S = BF3 VI, BCl3 VII, BBr3 VIII) und (CH3)2NBr · BF3 IX berichtet.Die Kristallstruktur von VII wurde anhand von dreidimensionalen Diffraktometerdaten bei -100°C bestimmt. Das Cl-Atom und eine Methylgruppe in der Dimethyl-N-Chloramineinheit zeigen Fehlordnung. Folgende Abstände wurden ermittelt: B—Cl: 183(2) pm, B—N: 167(3) pm, N—C: 152(3) pm (die Abstände zu den fehlgeordneten Positionen sind nicht angegeben).
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    Übergangsmetallphosphidokomplexe. XI. Diphosphenkomplexe des Typs (R3P)2Ni[η2-(PR′)2] und phosphidoverbrückte Nickel(I)-Komplexe des Typs [R3PNiP(SiMe3)2]2 (Ni—Ni) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 55-78 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Phosphido Complexes. XI. Diphosphene Complexes of the Type (R3P)2Ni[η2-(PR′)2] and Phosphido-Bridged Nickel(I) Complexes of the Type [R3PNiP(SiMe3)2]2(Ni—Ni)From reactions of complexes of the type (R3P)2NiCl2 1 (R = Me a, Et b, nBu c, iBu d, Ph e, iPr f, Cy g) with LiP(SiMe3)2 in a 1:2 molar ratio the diphosphene complexes (R3P)2Ni[η2-(PSiMe3)2] 4a-c and the phosphido-bridged nickel(I) complexes [R3PNiP(SiMe3)2]2 (Ni—Ni) 7a-g are available. Using low temperature n.m.r. measurements the monosubstitution products (R3P)2NiClP(SiMe3)2 2a-c and the nickel(0) diphosphane complexes R3PNi[η1-P2(SiMe3)4] 6a-g can be detected as intermediates. In reactions in a 1:1 molar ratio the formation of the diphosphorus complexes [(R3P)2Ni]2P2 9b, 9c is n.m.r. spectroscopically detectable. 1b reacts with LiP(SiMe3)CMe3 to give first the nickel(0) diphosphane complex Et3PNi[η1-P(SiMe3)CMe3—P(SiMe3)CMe3] 10, which can be isolated at low temperatures, finally yielding (Et3P)2Ni[η2-(PCMe3)2] 11 and [Et3PNiP(SiMe3)CMe3]2 (Ni—Ni) 12. 11 as well as (Et3P)2Ni[η2-(PPh)2] 14 can also be obtained reacting 1b with R′P(SiMe3)2 (R′ = CMe3, Ph). The best yields of diphosphene complexes result from [2+1] cyclocondensation reactions of 1a-c with P2(SiMe3)4 to give 4a-c and of 1b with [P(SiMe3)CMe3]2 to give 11. N.m.r. and mass spectral data are reported.
    Notes: Durch Umsetzungen von Komplexen des Typs (R3P)2NiCl2 1 (R = Me a, Et b, nBu c, iBu d, Ph e, iPr f, Cy g) mit LiP(SiMe3)2 im Molverhältnis 1:2 sind die Diphosphenkomplexe (R3P)2Ni[η2-(PSiMe3)2] 4a-c und die phosphidoverbrückten Nickel(I)-Komplexe [R3PNiP(SiMe3)2]2 (Ni—Ni) 7a-g zugänglich. Als Zwischenstufen können dabei durch Tieftemperatur-NMR-Messungen die Monosubstitutionsprodukte (R3P)2NiClP(SiMe3)2 2a-c und die Nikkel(0)-Diphosphankomplexe R3PNi[η1-P2(SiMe3)4] 6a-g nachgewiesen werden. Bei Umsetzungen im Molverhältnis 1:1 ist die Bildung der Diphosphorkomplexe [(R3P)2Ni]2P2 9b, 9c NMR-spektroskopisch nachweisbar. 1b reagiert mit LiP(SiMe3)CMe3 über den bei tiefen Temperaturen isolierbaren Nickel(0)-Diphosphankomplex Et3PNi[η1-P(SiMe3)CMe3—P(SiMe3) CMe3] 10 zu (Et3P)2Ni[η2-(PCMe3)2] 11 und zu [Et3PNiP(SiMe3)CMe3]2 (Ni—Ni) 12. 11 ist ebenso wie (Et3P)2Ni[η2-(PPh)2] 14 auch aus 1b und R′P(SiMe3)2 (R′ = CMe3, Ph) erhältlich. Die besten Ausbeuten an Diphosphenkomplexen ergeben [2+1] Cyclokondensationsreaktionen von 1a-c mit P2(SiMe3)4 zu 4a-c und von 1b mit [P(SiMe3)CMe3]2 zu 11. NMR-spektroskopische und massenspektrometrische Daten werden mitgeteilt.
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    Die Röntgenstrukturanalyse des Triformamids und des Tris(dichlormethyl)amins (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 107-112 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: X-Ray Structure Determinations of Triformamide and Tris(dichlormethyl)amineTriformamide, N(CHO)3 (I) and Tris(dichlormethyl)amine, N(CHCl2)3 (II), both crystallize in the hexagonale space group P63/m with 2 formula units per cell. The molecular symmetry is C3h in both cases, that means I is totally planar, II consists of a planar NC3H3 skeleton. The structure was refined to an R-value of 0,031 (I) and 0,028 (II), respectively.
    Notes: Triformamid, N(CHO)3 (I) und Tris(dichlormethyl)amin, N(CHCl2)3 (II), kristallisieren in der hexagonalen Raumgruppe P63/m mit jeweils 2 Formeleinheiten in der Elementarzelle. Die Molekülsymmetrie ist in beiden Fällen C3h, d. h. I ist völlig planar, II besitzt ein planares NC3H3-Gerüst. Die Strukturen wurden bis zu einem R-Wert von 0,031 (I) bzw. 0,028 (II) verfeinert.
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    Zur Kenntnis von Na4[CrO4] (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 137-141 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Na4(CrO4)Dark-green single crystals of Na4[CrO4] were obtained for the first time. (Na2O/Cr2O3; Na:Cr = 4:1 not exactly closed Ni-tube; 1000°C; 30 d). It is isostructural to Na4(CoO4); space group P1, a = 859.7 pm, b = 569.8 pm, c = 640 pm, α = 124°C, β = 98.4°, γ = 98.9°, Z = 2.The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Effective Ionic Radii, MEFIR, are calculated.
    Notes: Erstmals wurden klar durchsichtige, plättchenförmige, dunkelgrüne Einkristalle von Na4[CrO4] dargestellt (Na2O/Cr2O3, Na:Cr = 4:1; nicht exakt dichtes Ni-Röhrchen, 1000°C; 30 d). Es liegt der Na4(CoO4) Typ vor. RG P1 a = 859,7 pm, b = 569,8 pm, c = 640 pm, α = 124°, β = 98,4°, γ = 98,9°, Z = 2.Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN, diese über Mittlere Effektive Ionenradien, MEFIR, werden berechnet.
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    Neue Oxozincate mit Inselstruktur: K4[ZnO3] Mit einem Anhang über Rb7Na[ZnO3]2 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 122-136 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Nesozincates: K4[ZnO3], Rb7Na[ZnO3]2For the first time A) K4[ZnO3] and B) Rb7Na[ZnO3]2 have been prepared (from the binary oxides). They represent the first oxozincates of the alkali metals in which the coordination number of Zn2+ is exclusively 3 (carbonate-like groups [ZnO3]). Both oxides crystallize triclinic, space group P1 with A): a = 1103.3(3), b = 881.3(3), c = 698.2(2) pm, α = 109.65(2)°, β = 89.56(2)°, γ = 102.41(3)° and Z = 4, and B): a = 1128.3(3), b = 974.5(3), c = 711,8(2) pm, α = 114.12(2)β, = = 88.46(3)°,γ = 106.48(2)° and Z = 4.Their crystal structures have been determined from single crystal data (four circle diffractometer) and refined to R = 10.1%, Rw = 7.8% (2905 unique I0(hkl)) and R = 19.5%, Rw = 17.3% (2269 unique I0(hkl)), respectively. The Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN) and Mean Fictive Ionic Radii (MEFIR) have been calculated.
    Notes: Neu dargestellt wurden A) K4[ZnO3] und B) Rb7Na[ZnO3]2 (aus den binären Oxiden). Es sind dies die ersten Alkalimetalloxozincate, in denen Zn2+ ausschließlich die Koordinationszahl 3 gegen O2- annimmt (carbonatanaloge Gruppen [ZnO3]). Beide Oxide kristallisieren triklin, Rgr. P1 mit A): a = 1103,3(3), b = 881,3(3), c = 698,2(2) pm, α = 109,65(3)°, β = 89,56(2)°, γ = 102,41(3)° und Z = 4, bzw. B): a = 1128,3(3), b = 974,5(3), c = 711,8(2) pm, α = 114,12(2)°, β = 88,46(3)°, γ = 106,48(2)° und Z = 4. Die Kristallstrukturen wurden aus Vierkreisdiffraktometerdaten bestimmt und bis R = 10,1%, Rw = 7,8% (2905 I0(hkl)) bzw. R = 19,5%, Rw = 17,3% (2269 I0(hkl)) verfeinert. Der Madelunganteil der Gitterenergie (MAPLE) sowie Mittlere Fiktive Ionenradien (MEFIR) und Effektive Koordinationszahlen (ECoN) wurden berechnet.
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  • 86
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    Eine neue einfache Methode zur Entalkylierung von Phosphon- und Phosphinsäureestern (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 147-151 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Facile Method for the Dealkylation of Phosphonic and Phosphinic Acid EstersThe synthesis of phosphonic and phosphinic acid esters of the type is realized by reaction of dialkylphosphonates and O-alkylphosphinates with chlorotrimethylsilane in the presence of catalytical amounts of NH4Cl and hexamethyldisilazane (HMDZ).
    Notes: Die Synthese von Phosphon- und Phosphinsäureestern des Typs wird durch Umsetzung von Phosphonsäuredialkylestern und Phosphinsäurealkylestern mit Trimethylchlorsilan in Gegenwart katalytischer Mengen NH4Cl und Hexamethyldisilazan (HMDZ) beschrieben.
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  • 87
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    Kaliumnatriumsulfid KNaS, ein neues Interalkalimetallsulfid (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 169-176 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Potassium Sodium Sulphide, KNaS: A New Inter Alkali Metal SulphideHitherto unknown KNaS has been prepared by annealing a mixture of Na2S and K2S. X-ray single crystal structure determination has been performed. The hygroscopic, colorless compound crystallizes in the orthorhombic space group Pnma (Z = 4) with the lattice parameters a = 770.3(1), b = 460.4(1), c = 829.3(1) pm. Refining of the structure lead to a least squares residue of 0.035. KNaS is isostructural to PbCl2. The S2- are hexagonally closest-packed. Sulphur tetrahedra occupied by sodium ions share cis-located edges forming chains interconnected by vertices. The K+ are situated out of the center of octahedral sites diminishing the repulsion of the distinct metal ions. The new description of the PbCl2-type structure is corroborated by group-subgroup analysis.
    Notes: Bislang unbekanntes KNaS wurde durch Tempern eines Gemenges von Na2S und K2S dargestellt. Das farblose, hygroskopische Sulfid kristallisiert in der Raumgruppe Pnma (Z = 4) mit a = 770,3(1) pm, b = 460,4(1) pm und c = 829,3(1) pm. Die Struktur wurde über Röntgenbeugung an Einkristallen bestimmt (R = 0,035). KNaS ist antiisotyp mit PbCl2. Die Anionen S2- bilden eine verzerrt hexagonal dichteste Kugelpackung. NaS4-Tetraeder sind über cisständige Kanten zu Ketten verknüpft, die untereinander über Spitzen verbunden sind. Die K+ befinden sich in den Oktaederlücken und sind zur Verminderung der elektrostatischen Abstoßung von den Na+ aus deren Zentren gerückt. Die Gruppe-Untergruppe-Analyse unterstützt die neuartige Beschreibung der PbCl2-Struktur.
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  • 88
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    [ReCl3(NSCl)2(CH3CN)]. Synthese, IR-Spektrum und Kristallstruktur (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 177-182 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [ReCl3(NSCl)2(CH3CN)]. Synthesis, I. R. Spectrum, and Crystal StructureBlack, moisture sensitive crystals of the title compound are obtained from [ReCl3(NSCl)2]2 and acetonitrile in dichloromethane. The complex is characterized by its i.r. spectrum and an X-ray crystal structure determination (2483 observed independent reflexions, R = 0.035). Crystal data: triclinic, space group P1, Z = 2, a = 681.8, b = 899.9, c = 1104.0 pm, α = 110.50, β = 97.90 and γ = 101.34°. In the monomeric [ReCl3(NSCl)2(CH3CN)] molecule the Re atom has a distorted octahedral coordination with meridional arrangement of the Cl atoms. The chlorothionitrene ligands have nearly linear ReNS groups with bond lengths that correspond to double bonds (ReN 178 and 179 pm); this agrees with the NReN bond angle of 100°.
    Notes: Die Titelverbindung entsteht in Form schwarzer, feuchtigkeitsempfindlicher Kristalle aus [ReCl3(NSCl)2]2 und Acetonitril in Dichlormethan. Der Komplex wird durch das IR-Spektrum und durch eine röntgenographische Strukturbestimmung charakterisiert. [ReCl3(NSCl)2(CH3CN)] kristallisiert triklin in der Raumgruppe P1 mit Z = 2 und den Gitterkonstanten a = 681,8; b = 899,9; c = 1104,0 pm; α = 110,50°; β = 97,90°; γ = 101,34° (2483 unabhängige beobachtete Reflexe, R = 3,5%). In dem monomeren Molekülkomplex ist das Rheniumatom verzerrt oktaedrisch von drei meridional angeordneten Chloratomen, von dem N-Atom des Acetonitrilliganden und von den N-Atomen der beiden cis-ständigen Chlorthionitrengruppen umgeben. Die ReN-Abstände der ReNSCl-Gruppen entsprechen Doppelbindungen (178 bzw. 179 pm); im Einklang hiermit beträgt der NReN-Bindungswinkel 100°.
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  • 89
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    Untersuchungen an oxidischen Katalysatoren. XLIV. Beeinflussung des katalytischen Verhaltens modifizierter Zeolithe vom Typ ZSM-5 durch thermische BehandlungProfessor Wolfgang Wieker zum 60. Geburtstage am 19. April 1987 gewidmet (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 547 (1987), S. 142-148 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Oxide Catalysts. XLIV. Modification of the Catalytic Behavior of Modified ZSM-5 Zeolites by Thermal TreatmentThe catalytic activity, the shape selectivity, and the deactivation behavior of ZSM-5 in paraffin cracking reactions can be regulated by a thermal pretreatment. A minimum of the deactivation rate as a function of zeolite pretreatment time at 600°C found in the hexane cracking could be verified in the methanol conversion reaction to gasoline.
    Notes: Die katalytische Aktivität, die Formselektivität und das Aktivität-Zeit-Verhalten des ZSM-5 beim Spalten von Paraffinen kann durch thermische Vorbehandlung stark beeinflußt werden. Ein in der Spaltung von Hexan gefundenes Minimum der Desaktivierungsgeschwindigkeit als Funktion der Dauer der Vorbehandlung bei 600°C konnte in der Methanolumwandlung zu Benzin verifiziert werden.
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  • 90
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    Salze und Ester der 1,2-Hydrazin-bis(thiocarbonsäure) Kristallstrukturen von K2[OSC—N2H2—CSO] · 2 H2O, CH3S—CO—N2H2—CO—SCH3 und CH3O—CS—N2H2—CS—OCH3 bei 140 K (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 547 (1987), S. 158-166 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Salts and Esters of 1,2-Hydrazin-bis(thiocarboxylic)acid. Crystal Structures of K2[OSC—N2H2—CSO] · 2 H2O, CH3S—CO—N2H2—CO—SCH3, and CH3O—CS—N2H2—CS—OCH3 at 140 KThe anion [OSC—N2H2—CSO]2- and the molecules CH3S—CO—N2H2—CO—SCH3 and CH3O—CS—N2H2—CS—OCH3 exhibit nonplanar structures in the solid state. The dihedral angles beetween either of the two strictly planar R—CX—NH groups of each molecule are 78.8°, 77.5°, and 104.5°, respectively. The N—N bond lengths are 138.5 pm in all three compounds. The N—H groups participate in hydrogen bonds.
    Notes: Das Anion von K2[OSC—N2H2—CSO] · 2 H2O, sowie die Moleküle CH3S—CO—N2H2—CO—SCH3 und CH3O—CS—N2H2—CS—OCH3 besitzen im festen Zustand nichtplanare Konformationen. Die Diederwinkel zwischen den beiden jeweils planaren Molekülhälften betragen 78,8°, 77,5° bzw. 104,5°. Die N—N-Bindungslänge beträgt übereinstimmend in den drei Verbindungen etwa 138,5 pm. Die N—H-Gruppen sind an Wasserstoffbrückenbindungen beteiligt.
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  • 91
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    Die Synthese von CF3TeTeCF3 und Reaktionen mit den Elementen Hg, Cd, Cu und Ag (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 547 (1987), S. 167-172 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Preparation of CF3TeTeCF3 and Reactions with the Elements Hg, Cd, Cu, and Ag(CF3)2Te2 is a main product of the photochemical reaction of (CF3)2Te with e.g. furan and can be separated in more than 40% yield. It quantitatively reacts with mercury and cadmium to give the new compounds (CF3Te)2Hg and (CF3Te)2Cd, respectively. With copper some CF3—Cu compounds are formed, whereas with silver no reaction takes place.
    Notes: (CF3)2Te2 entsteht als Hauptprodukt bei der photochemischen Reaktion von (CF3)2Te mit z. B. Furan und kann in mehr als 40% Ausbeute isoliert werden. (CF3)2Te2 reagiert quantitativ mit Hg und Cd zu den neuen Verbindungen (CF3Te)2Hg bzw. (CF3Te)2Cd. Mit Cu werden nicht isolierbare CF3—Cu-Verbindungen gebildet, während mit Ag keine Reaktion stattfindet.
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  • 92
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    Zur Protonierung und Methylierung des 1, 1-Dicyanoethylen-2, 2-dithiolat Dianions: Präparative und strukturelle UntersuchungenProfessor Rudolf Hoppe zum 65. Geburtstage am 29. Oktober 1987 gewidmet (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 553 (1987), S. 95-105 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Protonation and Methylation of 1, 1-Dicyanoethylene-2, 2-dithiolate Dianion. Preparative and Structural InvestigationsProtonation of alkaline metal salts of [S2C = C(CN)2]2- (I) in water yields a product of composition H2S2C4N2 (II). The species has to be formulated as dimere and crystallizes with two moles DMSO from DMSO solution with space group C2/c and a = 20.611(3), b = 4.800(1), c = 20.638(3) Å, β = 103.3(1)°, Z = 4. The X-ray structural analysis shows II to be a centrosymmetric 1, 3-Dithiacyclobutane system.On methylation of I with CH3I in the molar ratio 1:1, the monomethylated anion III can be isolated as AsPh4 salt. The compound crystallizes in the monoclinic space group P21/c, with a = 23.632(2), b = 14.304(1), c = 7.989(1) Å, β = 100.1(8)° and Z = 4. There are nearly planar anions [MeS(S)C=C(CN)2]- with an anti-conformation of the MeS group.
    Notes: Alkalimetallsalze des Dianions [S2C=C(CN)2]2- (I) liefern bei Protonierung in wässriger Lösung ein Produkt der Zusammensetzung H2S2C4N2 (II). II erweist sich als dimeres H4S4C8N4 und kristallisiert mit 2 mol DMSO in der Raumgruppe C2/c mit a = 20,611(3), b = 4,800(1), c = 20,638(3) Å, β = 103,3(1)° und Z = 4. Die Strukturanalyse steht in Einklang mit NMR- und IR-Daten und liefert für II ein zentrosymmetrisches Desaurin.Die Methylierung von I mit CH3I im Verhältnis 1:1 liefert das Mono-S-methylprodukt (III), das in From des Tetraphenylarsoniumsalzes strukturell charakterisiert wurde. Die Verbindung kristallisiert in der Raumgruppe P21/c mit a = 23,632(2), b = 14,304(1), c = 7,989(1) Å, β = 100,1(8)° und Z = 4. Die Anionen III sind nahezu planar und zeichnen sich durch eine anti-Konformation der CH3S-Gruppierung aus.
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    Na3Al2Nb34O64 und Na (Si, Nb) Nb10O19: Clusterverbindungen mit isolierten Nb6-OktaedernProfessor Rudolf Hoppe zum 65. Geburtstage am 29. Oktober 1987 gewidmet (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 553 (1987), S. 106-122 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Na3Al2Nb34O64 and Na (Si, Nb) Nb10O19. Cluster Compounds with Isolated Nb6-OctahedraHexagonal ormolu coloured plates of the new compounds Na3Al2Nb34O64 (I) and Na(Si, Nb)Nb10O19 (II) were prepared by heating pellets of NaF, Al2O3, NbO2 and NbO (3:1:8:2) and NaF, NbO2 and NbO (1:4:2), respectively, at approx. 850°C. I was contained in a sealed gold capsule, II in a silica tube. The Si incorporated in II originates from the container material. Both compounds crystallize in R 3, I with a = 784.4(1), c = 7065(1) pm, Z = 3 and II with a = 784.1(1), c = 4221.8(5) pm, Z = 6. I and II represent new structure types. They contain the same characteristic structural units, namely discrete Nb6O12 clusters (dNb-Nb = 283 ± 4 pm) and Nb2O10 units with Nb-Nb dumbells (dNb-Nb ≍ 269 pm) in edgesharing coordination octahedra. In addition NbO6 octahedra containing Nb in the oxidation state + 5 and NaO12 cube-octahedra occur in both compounds besides AlO4 and SiO4 tetrahedra in I and II, respectively. The structures can be described in terms of a common closepacking of O and Na atoms together with Nb6 octahedra.
    Notes: Hexagonale, altgoldfarbene PlättChen der neuen Verbindungen Na3Al2Nb34O64 (I) bzw. Na(Si, Nb) Nb10O19 (II) wurden durch Erhitzen von zu Pillen gepreßten Gemengen aus NaF, Al2O3, NbO2 und NbO (3:1:8:2) bzw. NaF, NbO2 und NbO (1:4:2) bei etwa 850°C dargestellt. I war in einem geschlossenen Au-Rohr, II in einer Quarzampulle eingeschlossen; das in II eingebaute Si stammt aus der Gefäßwand. Beide Verbindungen kristallisieren in R 3, I mit a = 784,4(1), c = 7065(1) pm und Z = 3, II mit a = 784,1(1), c = 4221,8(5) pm und Z = 6.I und II bilden jeweils einen neuen Strukturtyp. Beide enthalten als charakteristische Baugruppen diskrete Nb6O12-Cluster (dNb-Nb = 283 ± 4pm) sowie Nb2O10-Einheiten mit Nb-Nb-Paaren (dNb-Nb ≍ 269 pm) und kantenverknüpften Koordinationsoktaedern. Ferner liegen NbO6-Oktaeder mit Nb in der Oxidationsstufe + 5, und NaO12-Kuboktaeder sowie in I AlO4-bzw. in II SiO4-Tetraeder vor. Die Strukturen lassen sich mit gemeinsam dichten Packungen von O-Atomen, Na-Atomen und Nb6-Oktaedern beschreiben.
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    Synthese und Charakterisierung einer neuen metallacyclisChen Verbindung des OsmiumsProfessor Rudolf Hoppe zum 65. Geburtstage am 29. Oktober 1987 gewidmet (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 553 (1987), S. 123-126 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Characterization of a New Metallacyclic Compound of OsmiumThe bissilylated phosphorane, Me3SiNP(Ph2)CH2(Ph2)PNSiMe3 1 reacts with OsO4 via the migration of SiMe3 groups to give a new metallacycle 2 containing OsVIII. 1H, 31P, and 29Si n.m.r. spectroscopic investigations confirm the cyclic structure of 2.
    Notes: Das bissilylierte Phosphoran, Me3SiNP(Ph2)CH2(Ph2)PNSiMe3 1 reagiert mit OsO4 unter Wanderung der Me3Si-Gruppen zum neuen Osmium (VIII) enthaltenden Metallacyclus 2. 1H-, 31P- und 29Si-NMR Untersuchungen stützen den cyclisChen Aufbau von 2.
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    Über die Reaktion von W3O mit lod. Darstellung, Kristallstruktur und Eigenschaften von WOI3Professor Rudolf Hoppe zum 65. Geburtstage am 29. Oktober 1987 gewidmet (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 553 (1987), S. 127-135 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Reaction of W3O with Iodine: Preparation, Crystal Structure, and Properties of WOI3The novel tungsten oxide iodide WOI3 is obtained from the reaction of the metalrich tungsten oxide W3O (also known as ‘β-tungsten’) with iodine in a sealed glass tube placed in a temperature gradient (440-400°C). In the low-temperature region WOI3 is formed as mouse-grey intergrown needle-like crystals. WOI3 crystallizes in the tetragonal NbOCl3 structure type, space group P42/mnm, with a = 12.346(2), c = 3.765(1) Å (20°C). The crystal structure at - 130°C was determined from single-crystal diffractometer data (R = 0.023). Results of magnetic susceptibility and vibrational spectroscopic measurements are given together with the mass spectrum of WOI3 obtained on heating.
    Notes: Die Darstellung des bisher unbekannten WOI3 gelingt, wenn man das in der Literatur auch als β-Wolfram bezeichnete Wolframoxid der Zusammensetzung W3O mit lod in einer Glasampulle im Temperaturgefälle (440-400°C) umsetzt. In der kalten Zone schlägt sich WOI3 in mausgrauen verfilzten Nadeln nieder. WOI3 kristallisiert tetragonal im NbOCl3-Typ in der Raumgruppe P42/mnm mit a = 12,346(2), c = 3,765(1) Å (20°C). Die Kristallstruktur bei-130°C wurde aus Einkristall-Diffraktometerdaten bestimmt (R = 0,023). Ergebnisse der Messungen der magnetischen Suszeptibilität und des Schwingungsspektrums sowie das beim Erhitzen von WOI3 erhaltene Massenspektrum werden angegeben.
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    Cis- und trans-1-Phosphabicyclo[4.4.0]decanProfessor Rudolf Hoppe zum 65. Geburtstage am 29. Oktober 1987 gewidmet (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 553 (1987), S. 136-146 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cis- and trans-1-Phosphabicyclo[4.4.0]decaneA mixture of cis-(5a) and trans-1-phosphabicyclo [4.4.0] decane 5b has been prepared by free-radical cyclization of (CH2 = CH—CH2—CH2)2CH—PH2 10. The isomers could be separated in a pure state. Stereostructures have been assigned by 13C n.m.r. at 153 - 302 K. Equilibration of 5a and 5b by u.v. irradiation gave ⊲G°35 ≍ 0 kJ ° mol-1 · Activation parameters for ring inversion of “cis” stereoisomer 5a and its “cis” P-sulfid 17a are found to be ΔG° = 41.9 kJ · mol-1 and 39.7 kJ · mol-1, respectively. Treatment of 5a and 5b with H2O2, sulfur, selenium, HSO3F, CH3I, CS2, and Ni(CO)4, respectively, yield the corresponding derivatives. 1H, 13C, 31P, 77Se n.m.r. and i.r. data are reported.
    Notes: Durch radikalische Cyclisierung von (CH2=CH—CH2—CH2)2CH—PH2 10 wird eine Mischung von cis- (5a) und trans-1-Phosphabicyclo[4.4.0]decan (5b) erhalten. Nach Trennung in die reinen Stereoisomeren konnten die Strukturen durch 13C-NMR-Spektren bei 153 - 302 K zugeordnet werden. Gleichgewichtseinstellungen 5a ⇌ 5b durch UV-Bestrahlung ergaben bei 35°C einen ⊲G°-Wert nahe Null. Die Aktivierungsparameter für die Ringinversion von 5a und seinem Sulfid 17a betragen ⊲G = 41,9 kJ · mol-1 bzw. 39,7 kJ · mol-1. Umsetzungen von 5a und 5b mit H2O2, Schwefel, Selen, HSO3F, CH3I, CS2 und Ni(CO)4 führten zu den entsprechenden Derivaten. Werte der 1H-, 13C-, 31P- und 77Se-NMR-Spektren sowie IR-Daten der LNi(CO)3 (L = 5a, 5b) werden mitgeteilt.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19875531016
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    Beiträge zur Chemie der Schwefelhalogenide. 14. Die Kinetik des Zerfalls von Diioddisulfan und Perfluormethyliodsulfan (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 192-198 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contribution to the Chemistry of Sulfur-Halogen Compounds. 14. Decomposition Kinetics of Diiododisulfane and PerfluoromethaneiodosulfaneDue its bifunctional character, S2I2 decomposes by inter- as well as intramolecular iodine formation. A system of competing parallel and secondary reactions results.The main decomposition phase follows first order rate law and is strongly temperature dependent, on the other hand, perfluoromethaneiodosulfane decomposes obeying second order rate law, where K = 2.74 ± 0.03 × 10-4 l mol-1s-1 at 40°C.
    Notes: Die Bifunktionalität des S2I2 führt bei seinem Zerfall über inter- und intramolekulare Iodbildung zu einem System konkurrierender Folge- und Parallelreaktionen. Der Zerfall erfolgt in seiner Hauptphase nach einem Geschwindigkeitsgesetz 1. Ordnung und ist stark temperaturabhängig.Demgegenüber zerfällt Perfluormethyliodsulfan nach einem Geschwindigkeitsgesetz 2. Ordnung mit K = 2,74 ± 0,03 × 10-4 l mol-1s-1 bei 40°C.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19875440120
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    Koordinationsverbindungen des Silber(I) mit stickstoffhaltigen Liganden Kristallstruktur des NC—SCF2CF2S—CNProfessor Oskar Glemser xum 75. Geburtstage am 12. November 1986 gewidmet (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 209-214 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Coordination Compounds of Silver(I) with Nitrogen-Containing Ligands. Crystal Structure of NC—SCF2CF2S—CNThe reaction of F2S=NCN and NC—SCF2CF2S—CN with AgAsF6 leads to the coordination compounds (F2S=NCN)2AgAsF6 2 and (NC—SCF2CF2S—CN)2AgAsF6 5. NC—SCF2CF2S—CN 3 is formed by the reaction of ClSCF2CF2SCl with HCN as well as with Me3SiCN. 4 is a by-product of the reaction with HCN. 4 was characterized as a six-membered heterocycle. 3 was investigated by an X-ray single structure analysis. In the solid state the all-trans form was found.
    Notes: Die Reaktion von F2S=NCN und NC—SCF2CF2S—CN mit AgAsF6 führt zu den Koordinationsverbindungen (F2S=NCN)2AgAsF6 2 und (NC—SCF2CF2S—CN)2AgAsF6 5. NC—SCF2CF2S—CN 3 entsteht sowohl bei der Reaktion von ClSCF2CF2SCl mit HCN als auch mit Me3SiCN.4 ist ein Nebenprodukt aus der Umsetzung mit HCN. 4 konnte als sechsgliedriger Heterocyclus charakterisiert werden. 3 wurde durch eine Einkristallröntgenstruktur-Analyse untersucht. Es liegt im festen Zustand in der all-trans Form vor.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19875440122
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    Die elektrochemische Reduktion von CSSe und CSe2 in Dimethylformamid: Heterocyclische 1,2-Dichalkogenolate und ihre Koordinationschemie (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 199-208 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrochemical Reduction of CSSe and CSe2 in Dimethylformamide: Heterocyclic 1,2-Dichalcogenolates and their Coordination ChemistryStarting from carbon diselenide or carbon selenidesulfide the electrochemical preparation (electrosynthesis) of heterocyclic dichalcogenolates C3X52- (X = Se: dsis; X = S/Se: C3SxSey2-) is outlined. The 1,2-dichalcogenolate compounds were isolated and characterized as dibenzoyl derivatives. Bis- or tris-chelates of general type Am[M(C3X5)n] (with A = Bu4N+, Ph4As+; M = ZnII, PtII, PdII, NiIII, CuIII, AuIII, InIII; X = Se, S/Se; m = 1, 2, 3; n = 2, 3, respectively) are available directly from methanolic solutions of the dibenzoylates after hydrolytic cleavage of the latter with sodium methanolate. In addition bis-chelates Bu4N[Ni(C3X5)2] (X = Se, S/Se) have been characterized by cyclovoltammetry and epr spectroscopy and compared with the corresponding all-sulfur ligand compound Bu4N[Ni(dmit)2] (X = S). Arguments are given for the fact that the allselenium ligand dsis (X = Se) yields the CuIII or NiIII chelate at once whereas with dmit using identical conditions the metal(II) compounds are formed.
    Notes: Ausgehend von Selenkohlenstoff und Selenschwefelkohlenstoff wird die elektrochemische Darstellung heterocyclischer Dichalkogenolate C3X52- (X = Se: dsis; X = S/Se: C3SxSey2-), die als Dibenzoylverbindungen isoliert und charakterisiert werden, beschrieben. Aus den mit Alkalimethanolat erhaltenen Verseifungslösungen dieser Dibenzoylverbindungen sind Metall-bis- und -tris-Chelate der heterocyclischen 1, 2-Dichalkogenolate vom Typ Am[M(C3X5)n] (A = Bu4N+, Ph4As+; M = ZnII, PtII, PdII, NiIII, CuIII, AuIII, InIII; X = Se, S/Se; m = 1, 2, 3; n = 2, 3) unmittelbar zugänglich. Cyclovoltammetrisch und mittels EPR werden die Nickel(III)-Verbindungen Bu4N[Ni(C3X5)2] (X = Se, S/Se) charakterisiert und der analogen Schwefelverbindung Bu4N[Ni(dmit)2] (X = S) gegenübergestellt. Für die bei der Chelatisierung mit dsis (X = Se) beobachtete Metall(II)-Metall(III)-Oxydation bei Kupfer und Nickel werden Argumente erörtert.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19875440121
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    Masthead (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987) 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19875450201
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