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  • 1
    ISSN: 0044-2313
    Keywords: Carbosilanes ; Phosphanes ; Supercritical Fluid Chromatography (SFC) ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Analytical and Preparative Separation of Functional Carbosilanes and Phosphanes by Means of SFC (Supercritical Fluid Chromatography)Analytical and preparative separations of functional silanes, carbosilanes and phosphanes by means of SFC (supercritical fluid chromatography) using CO2 or CF3Cl as mobile phases are reported. The detecting system (an IR high pressure cell) of the apparatus which was developed by us is depicted. The separation of mixtures containing silanes with strongly polarizing groups proceeds successfully with Nucleosil-C18 and CO2 according to the molecular weights. Large differences in the polarity of the compounds give rise to a separation according to molecular weights, smaller ones to the types of compounds. The advantages of a separation by SFC are demonstrated using a mixture of 1,3,5-trisilacyclohexanes with SiH, CCl2 and SiF groups. The preparative separation is demonstrated using a mixture of 4 different groups of a toral 22 carbosilanes. Eight fractions were obtained each of which containing the compounds with the same number of Si atoms. The final separation was achieved by means of a pressure program (Nucleosil-C18, CO2). The preparative isolation of a cyclic phosphinoborane from a mixture of three components of the same type as well as the isolation of (Me3Si)3P from a mixture of P-rich silylphosphanes is reported.
    Notes: Es wird die analytische und präparative Trennung von funktionellen Silanen, Carbosilanen und Phosphanen mittels der SFC (SFC = Supercritical-Fluid-Chromatography) mit CO2 und CF3Cl als mobile Phasen beschrieben. Von der entwickelten Anlage wird das Detektorsystem (IR-Hochdruckzelle) dargestellt. Nach Untersuchungen an substituierten Silanen erfolgt die Auftrennung von Verbindungsgemischen mit stark polarisierenden Gruppen an Nucleosil-C18 mit CO2 nach Molekulargewichten; große Polaritätsunterschiede im Verbindungsgemisch begünstigen die Auftrennung nach Molgewichten, kleinere ermöglichen die Trennung nach Verbindungstypen. Der Vorteil der SFC-Trennung wird an 1,3,5-Trisilacyclo-hexanen mit SiH-, CCl2-, SiF-Gruppen demonstriert. Die präparative Trennung wird an einem Carbosilangemisch aus vier Verbindungsgruppen gezeigt, das an Nucleosil-C18 in acht Fraktionen mit Verbindungen jeweils gleicher Anzahl an Si-Atomen zerlegt wurde. Die Auftrennung des gesamten Gemisches in 22 Verbindungen erfolgte über ein Druckprogramm an Nucleosil-C18/CO2. Es wird die präparative Abtrennung eines cyclischen Borphosphans aus einem Gemisch mit drei Komponenten des gleichen Verbindungstyps sowie die Abtrennung von (Me3Si)3P aus einem Gemisch P-reicher Silylphosphane beschrieben.
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  • 2
    ISSN: 0044-2313
    Keywords: Carbosilanes ; Cu-catalyzed reactions of silicon with C-chlorinated 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexanes ; crystal structures of hexadecachloro-1,3,5,7,9,11,13,14-octasiladispiro[5.1.5.1]tetradecane ; decachloro-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane and decachloro-2-trichlorosilyl-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation of Organosilicon Compounds 113. Reactions of C-chlorinated 1,1,3,3,5,5-Hexachloro-1,3,5-trisilacyclohexanes with Si(Cu cat.). Structures of Hexadecachloro-1,3,5,7,9,11,13,14-octasiladispiro[5.1.5.1]tetradecane 12, Decachloro-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane 13 and Decachloro-2-trichlorosilyl-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane 14Elemental Si(Cu cat.) was treated with 1,1,2,2,3,3,5,5-octachloro-1,3,5-trisilacyclohexane 3, 1,1,2,2,3,3,4,4,5,5-decachloro-1,3,5-trisilacyclohexane 4 and with (Cl2Si—CCl2)3 5, resp., in a stirred bed reactor at 330°C. The products can be understood as to be formed by silylation, hydrogenation, degradation, rearrangement and condensation reactions all of them starting from the CCl2 groups of the trisilacyclohexanes. Especially remarkable is Si8C6H8Cl16 12 with a C-spiro linked framework formed by a trisilacyclohexane, a disilacyclobutane and another trisilacyclohexane building block. In two further tricyclic carbosilanes Si6C6H10Cl10 13 and Si7C6H9Cl13 14, two trisilacyclohexane rings each share an opposite Si—C bond with a disilacyclobutane. Another group of compounds includes compounds consisting of two 1,3,5-trisilacyclohexane rings linked by either a C=C or a C=C=C unit. Moreover some derivatives of 1,3-disilacyclopentenes are formed obviously by a contraction of the C-chlorinated 1,3,5-trisilacyclohexane rings. Compound 12 crystallizes in the monoclinic space group P21/n (no. 14) with a = 1 307.8, b = 1 184.2, c = 984.4 pm, β = 93.58° and Z = 2 molecules per unit cell. 13 crystallizes in the triclinic space group P1 (no. 2) with a = 885.7, b = 911.6, c = 868.3 pm, α = 113.15°, β = 75.36° γ = 119.22° and Z = 1. 14 crystallizes in the monoclinic space group P21/c (no. 14) with a = 1853.2, b = 912.9, c = 1725.3 pm, β = 112.69° and Z = 4.
    Notes: 1,1,2,2,3,3,5,5,-Octachlor-1,3,5-trisilacyclohexan 3, 1,1,2,2,3,3,4,4,5,5-Decachlor-1,3,5-trisilacyclohexan 4 und (Cl2Si—CCl2)3 5 wurden mit Si(Cu) bzw. Cu im Rührbett bei 330°C umgesetzt. Die Reaktionen gehen von den CCl2-Gruppen der Trisilacyclohexane aus, und die verschiedenen Reaktionsprodukte sind durch Silylierung, Hydrierung, Kondensation und Umlagerung zu erklären. Besonders bemerkenswert ist das Si8C6H8Cl16 12, in dessen Grundgerüst zwei 1,3,5-Trisilacyclohexane über einen Disilacyclobutanring C-spiroverbrückt sind. In zwei tricyclischen Carbosilanen, Si6C6H10Cl10 13 und Si7C6H9Cl13 14, sind zwei Trisilacyclohexane über einen Disilacyclobutanring verbunden, der unter Ausbildung von zwei Si—C-Bindungen zwischen gegenüberliegenden SiCl- und CCl-Gruppen aufgebaut ist. Eine weitere Gruppe enthält Verbindungen, in denen zwei 1,3,5-Trisilacyclohexanringe entweder über eine C=C- oder C=C=C-Gruppe verbunden sind. Es entstehen auch 1,3-Disilacyclopentenderivate, deren Bildung auf eine Ringverengung der C-chlorierten 1,3,5-Trisilacyclohexane zurückgeführt wird. Verbindung 12 kristallisiert monoklin in der Raumgruppe P21/n (Nr. 14) mit a = 1 307,8, b = 1 184,2, c = 984,4 pm, β = 93,58° und Z = 2 Molekülen pro Elementarzelle; 13: triklin in der Raumgruppe P1 (Nr. 2) mit a = 885,7, b = 911,6, c = 868,3 pm, α = 113,15°, β = 75,36°, γ = 119.22° und Z = 1; 14: monoklin in der Raumgruppe P21/c (Nr. 14) mit a = 1 853,2, b = 912,9, c = 1 725,3 pm, β = 112.69° und Z = 4.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 105 (1980), S. 143-152 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The influence upon differnt cellular and humoral parameters of hemopoiesis of three structurally unrelated, highly purified bacterial cell-wall components (BCWC) was investigated. The spleens of C57BL/6 mice assayed 6 days after the injection of either lipid A or outer-membrane lipoportein, but not murein, showed a marked increase in granulocyte-macrophage, eosinophil, and megakaryocyte progenitor cell levels. The number of pluripotent hemopoietic stem cells (CFU-S) also increased in the spleens of mice treated with either lipid A or lipoprotein. Similar results were obtained following the injection of lipoprotein or lipid A into CBA or C57BL/6.nu mice. Genetically anemic Wf/Wf mice were found to have spontaneously elevated numbers of splenic progenitor cells, which increased further after the injection of lipid A. The proportions of the different splenic progenitor cell types were similar in both untreated and lipid A treated Wf/Wf mice, and in normal littermate controls.When tested in vitro, unfractionated or partially purified post-lipid A serum was found to stimulate the growth of granulocyte-macrophage progenitor cells (GM-CFC), but no detectable stimulation of eosinohphil, megakryocyte, or erythroid progenitor cells was observed. The data suggest that the rise in splenic levels of the different progenitor cells is not mediated by the corresponding types of CSF, but more likely by proliferation and differentiation of CFU-S.
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  • 4
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Molecular changes occur at the surface of hemopoietic cells during differentiation from progenitor cells to mature granulocytes and macrophages. The differential expression of surface carbohydrate residues has been probed using lectins and the results used to purify normal mouse granulocyte-macrophage progenitor cells. Ten different lectins were screened for selective interaction with mouse hemopoietic colony-forming cells (CFCs), using agglutination or a quantitative analysis of the number of fluoresceinated lectin molecules bound per cell using a fluorescence activated cell sorter (FACS). Pokeweed mitogen (PWM), Helix pomatia agglutinin (HPA), soybean agglutinin (SBA), and peanut agglutinin (PNA) preferentially bound to CFCs so that it was possible to enrich 4 to 10-fold for these progenitor cells by sorting for the highly fluorescent cells. Further analysis of the low and high angle light scattering characteristics of the CFCs indicated that these cells were polydisperse, but could be enriched ten-fold by selecting for cells with high intensity low angle (90°) scatter and low intensity high angle (90°) scatter. PWM gave the best enrichment (10 to 15-fold) for adult bone marrow CFCs, for CFCs from fetal sources (fetal liver, fetal blood), and for CFCs from the spleens of mice injected previously with outer membrane lipoprotein from E. coli. Three parameter sorting for CFC using the FACS (low angle scatter, high angle scatter, and PWM-fluorescence) resulted in large enrichment factors (16 to 50-fold) for CFCs from all the above sources. Over 7% of the cells sorted from bone marrow, 10% of the cells sorted from post-lipoprotein spleen, and 28% of the cells sorted from fetal peripheral blood were hemopoietic CFCs. Ninety percent of the cells in these fractions had the morphology of blast cells or myelocytes. Thus, it was possible to identify the morphological characteristics of the hemopoietic progenitor cells. Screening of other developmental systems using quantitation of fluorescence with lectins should prove of general value for the purification of selected differentiation states.
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  • 5
    ISSN: 0570-0833
    Keywords: Carbosilanes ; Silanes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The present paper describes the formation of silicon-carbon compounds (carbosilanes), the molecular skeletons of which consist of alternate Si and C atoms, and which can be obtained by thermal decomposition of Si(CH3)4, CH3SiCl3, (CH3)2SiCl2, and (CH3)3SiCl. The description of the formation of carbosilanes is followed by a discussion of the reactions of polychlorinated carbosilanes with organometallic compounds.
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