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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 596 (1991), S. 89-92 
    ISSN: 0044-2313
    Keywords: Calcium oxychloride ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: An Oxychloride of Calcium: Ca4OCl6Ca4OCl6 (hexagonal, P63mc, Z = 2), a = 905.8(3), c = 686.3(4) pm, (R = 0.031) crystallizes as colourless needles from reducing melts (CaCl2, Ca) that contain small amounts of „oxygen“. It contains „isolated“ tetrahedral units [Ca4O] and is isotypic with e.g., Ba4OCl6, Yb4OCl6 and K6HgS4. Ca4OCl6 does not form in the dehydration process of, for example, CaCl2 · 6 H2O.
    Notes: Ca4OCl6 (hexagonal, P63mc, Z = 2, a = 905.8(3)); c = 686.3(4) pm, (R = 0,031) kristallisiert in Form farbloser Nadeln aus „reduzierenden Schmelzen“ (CaCl2, Ca), die wenig „Sauerstoff“ enthalten. Es enthält „isolierte“ tetraedrische [Ca4O]-Einheiten und ist isotyp mit z. B. Ba4OCl6, Yb4OCl6 oder K6HgS4. Ca4OCl6 entsteht nicht beim Entwässern von z. B. CaCl2 · 6 H2O.
    Additional Material: 1 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 183-186 
    ISSN: 0006-3592
    Keywords: Gluconobacter oxydans ; 5-ketogluconic acid ; tartatic acid ; vanadate ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The dependence of tartaric acid production by Gluconobacter oxydans ssp. oxydans ATCC 19357 and G. oxydans ssp. suboxydans ATCC 621 on vanadate was investigated. It was found with both organisms that trataric acid could only be produced in a medium containing vanadate (NH4VO3). A proposed intermediate of the tartaric acid metabolism in G. oxydans, 5-ketogluconic acid, was tested on its reactivity in the presence of the oxidizing catalyst vanadate. It could be shown that 5-ketogluconic acid and the catalyst vanadate, but not the activity of G. oxydans, were responsible for the formation of tartaric acid. G. oxydans was not able to produce tartaric acid by itself. The stereochemical identity of the formed tartaric acid could be identified as the L-(+)-type. Oxalic acid was formed from 5-ketogluconic acid with vanadate in the absence and in the presence of G. oxydans. The ratio of oxalic acid to tartaric acid was 1:1.
    Additional Material: 1 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 353-358 
    ISSN: 0006-3592
    Keywords: Bagasse hemicellulose hydrolysate ; chemostat ; Candida blankii ; D-xylose ; single cell protein ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A Candida blankii yeast isolate was grown in sugar cane bagasse hemicellulose hydrolysate at 38°C in carbon-limited chemostat culture. The pretreatment of the acid hydrolysate prior to microbial cultivation consisted of partial neutralization with ammonia and sodium hydroxide, plus the addition of phosphorus, which was the only other growth-limiting nutrient apart from nitrogen. The cell yield coefficient on nitrogen was 16.78. The critical dilution rate was higher (0.35 h-1) in diluted hydrolysate than in undiluted hydrolysate (0.21 h-1). In undiluted hydrolysate at a dilution rate of 0.1 h-1 and pH 4, where aseptic procedures proved unnecessary, the cell and protein yield coefficients were 0.53 and 0.26, respectively, and no residual carbon substrates (D-xylose, L-arabinose, D-glucose, and acetic acid) were detected. The cell yield on oxygen increased linearly as a function of dilution rate. The cellular content of protein, carbohydrate, and RNA also increased with an increase in dilution rate, whereas the DNA content decreased slightly. C. blankii has considerable potential for the production of single cell protein from hemicellulose hydrolysate, because of its ability to utilize all of the major carbon substrates in the hydrolysate at a low pH and at a relatively high temperature with a high protein yield. © 1992 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 760-767 
    ISSN: 0006-3592
    Keywords: (R)-1-(1-naphthyl)ethylamine ; (R)-1-aminoindan ; subtilisin ; organic solvent ; stereoselective aminolysis ; immobilized enzyme ; continuous process ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An enzymatic process has been developed for the continuous production of the pharmaceutically important intermediate (R)-1-aminoindan and of the chiral resolving agent (R)-1-(1-naphthyl)ethylamine. The process consists of the subtilisin catalyzed stereoselective aminolysis of the racemic primary amine with an active ester in organic solvent. The competing nonenzymatic reaction has been suppressed by appropriate choice of solvent and reactant's concentration and by minimizing the time of contact between the amine and the active ester. Subtilisin was immobilized on glass beads and the reaction carried out in a continuous-flow column bioreactor. By using a 450-mL column bioreactor containing 5.7 g of subtilisin immobilized on 570 g of glass beads, 1.6 kg of racemic 1-(1-naphthyl)ethylamine was resolved after 320 h of continuous operation with only a slight loss of the enzymatic activity. During the whole process, the optical purity of the chiral amine eluting from the column was higher than 90%. A facile procedure was developed for separating the unreacted (R)-amine from the (S)-amide and for the recycling of the solvent 3-methyl-3-pentanol and the active ester 2,2,2-trifluoroethyl butyrate. © 1992 John Wiley & Sons, Inc.
    Additional Material: 2 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 602 (1991), S. 31-37 
    ISSN: 0044-2313
    Keywords: Alkali-iodoindates(III) ; indium ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structures of the Alkali-tetraiodoindates(III), AInI4 (A = Li, K, Rb, Cs)Single crystals of the yellow alkaliiodoindates(III), AInI4 (A = Li, K, Rb, Cs), are obtained from mixtures of the binary components by slow cooling of the melts. LiInI4 is isotypic with LiAlCl4: monoclinic, P21/c, Z = 4; a = 838.9(4); b = 751.2(3); c = 1526,7(8) pm; β = 92.67(4)°. KInI4 belongs to the ATIX4 type of structure (A = NH4, K, Rb; X = Br, I): cubic, F4 3c, Z = 24; a = 1990.8(1) pm. RbInI4 crystallizes with the β-GaBr2 type: trigonal, R3c, Z = 18; a = 2452.6(6); c = 978.6(4) pm. CsInI4 is isostructural with CsTII4: monoclinic, P21/c, Z = 4; a = 738.4(1); b = 1875.7(3); c = 853.6(2) pm; β = 105.75(2)°. In all structures almost regular tetrahedral polyhedra [InI4]- occur. The coordination numbers of the alkali cations cover the wide range from 6 (Li+) via 9 (Rb+) and 11 (Cs+) to 12 (K1+).
    Notes: Einkristalle der gelben Iodoindate(III) der Alkalimetalle, AInI4 (A = Li, K, Rb, Cs), erhält man aus Gemengen der binären Komponenten durch langsames Abkühlen der Schmelzen. LiInI4 ist isotyp mit LiAlCl4: monoklin, P21/c, Z = 4; a = 838,9(4); b = 751,2(3); c = 1526,7(8) pm; β = 92,67(4)°. KInI4 gehört zum ATIX4-Typ (A= NH4, K, Rb; X= Br, I): kubisch, F4 3c, Z = 24; a = 1990,8(1) pm. RbInI4 kristallisiert im β-Ga[GaBr4]-Typ: trigonal, R3c, Z = 18; a = 2452,6(6); c = 978,6(4) pm. CsInI4 ist isotyp mit CsTII4: monoklin, P21/c, Z = 4; a = 738,4(1); b = 1875,7(3); c = 853,6(2) pm; β = 105,75(2)°. Stets liegen annähernd tetraedrische Baugruppen [InI4]- vor. Die Koordinationszahlen der Alkali-Kationen überstreichen das Spektrum von 6 (Li+) über 9 Rb+, 11 (Cs+) bis 12 (K1+).
    Additional Material: 6 Tab.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 262-265 
    ISSN: 0044-2313
    Keywords: Ca3(BN2)2 ; Sr3(BN2)2 ; NaSr4(BN2)3 ; preparation ; structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Structure of Sr3(BN2)2The structure of Sr3(BN2)2 was determined on single-crystal X-ray data collected with a four-circle diffractometer. Sr3(BN2)2 crystallizes in the cubic space group Im3m (no. 229) with a = 764.56(3) pm and Z = 3. The structure contains linear BN3-2 ions with a B—N bond length of 135.8(6) pm. The straight forward synthesis employing metal nitrides plus boron nitride yielded crystalline powders of M3(BN2)2 (M = Ca, Sr) at 1100°C (5 days). Cubic indexing of guinier patterns gave a = 765.8(1) pm for M = Sr and a = 734.7(2) pm for M = Ca. The structure refinement on a single crystal of Sr3(BN2)2 revealed that one strontium site (2a; 0, 0, 0) is occupied by only about 50%. It has been tried to fully occupy this site with an alkali metal (A) to obtain ASr4(BN2)3 (Z = 2). Reactions with A = Na yielded crystalline powders. Cubic indexing of the guinier pattern analogous to that of Sr3(BN2)2 gave a = 754.2(1) pm.
    Notes: Die Struktur von Sr3(BN2)2 wurde anhand von Einkristall-Röntgendaten, die durch Messung an einem Vierkreisdiffraktometer erhalten wurden, bestimmt. Sr3(BN2)2 kristallisiert in der kubischen Raumgruppe Im3m (Nr. 229) mit a = 764,56(3) pm und Z = 3. Die Struktur enthält lineare BN3-2-Ionen mit einer Bindungslänge B—N von 135,8(6) pm. Die gezielte Darstellung aus den Metallnitriden und Bornitrid zu M3(BN2)2 (M = Ca, Sr) bei 1100°C (5 Tage) ergab kristalline Pulver. Kubische Indizierung der Guinierdiagramme gab a = 765,8(1) pm für M = Sr und 734,7(2) pm für M = Ca. Die Strukturverfeinerung an einem Einkristall von Sr3(BN2)2 zeigte, daß eine Strontiumlage (2a; 0,0,0) nur zu etwa 50% besetzt ist. Es wurde versucht, diese Lage mit einem Alkalimetall (A) entsprechend ASr4(BN2)3 (Z = 2) vollständig zu besetzen. Reaktionen mit A = Na ergaben kristalline Pulver, deren Guinierdiagramme analog zu Sr3(BN2)2 kubisch mit a = 754,2(1) pm indiziert werden konnten.
    Additional Material: 2 Ill.
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  • 7
    ISSN: 0044-2313
    Keywords: Alkali uranium halides, A2UX5 (A = K, Rb; X = Cl, Br, I) ; preparation ; crystal structure ; magnetic susceptibility ; UV-Vis spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese, Kristallstruktur, Magnetismus und Absorptionsspektren von Halogeniden des Typs A2UX5 (A = K, Rb; X = Cl, Br, I)Die ternären Uran(III)-halogenide A2UX5 (A = K, Rb; X = Cl, Br, I) wurden aus den binären Komponenten AX und UX3 in verschweißten Tantalampullen gewonnen. Nach Guinier-Aufnahmen (Raumtemperatur) kristallisieren sie sämtlich im K2PrCl5/Y2HfS5-Typ. Einkristall-Strukturverfeinerungen wurden für K2UI5 und Rb2UCl5 unternommen. Magnetische Suszeptibilitätsmessungen erfolgten mit einem SQUID-Magnetometer von Raumtemperatur bis zur Temperatur des flüssigen Heliums: Eindimensionale (innerhalb einer Kette) und dreidimensionale antiferromagnetische Ordnung wird bei tiefen Temperaturen, abhängig vom Abstand U3+—U3+, beobachtet. Absorptionsspektren wurden zwischen 4000 und 28000 cm-1 aufgenommen. Sie zeigen die für U3+ charakteristischen Übergänge und, abhängig vom Halogenid, sehr starke f - d Übergänge oberhalb 14000 bzw. 15000 cm-1.
    Notes: The ternary uranium(III) halides A2UX5 (A = K, Rb; X = Cl, Br, I) have been prepared from the binary components AX and UX3 in sealed tantalum containers. According to their Guinier X-ray powder patterns, they all crystallize with the K2PrCl5/Y2HfS5 type of structure. Lattice constants for ambient temperature are reported. Single-crystal structure refinemens were undertaken for K2UI5 and Rb2UCl5. Magnetic susceptibility data were recorded with a SQUID magnetometer from liquid helium to room temperature. One-dimensional (intrachain) and three-dimensional antiferromagnetic ordering occur at low temperatures dependent upon the U3+—U3+ distance. Absorption spectra were recorded between 4 000 and 28 000 cm-1. They show f - f transitions typical for U3+ and, depending on the halide, very strong f - d transitions above 14 000 to 15 000 cm-1, respectively.
    Additional Material: 8 Ill.
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  • 8
    ISSN: 0044-2313
    Keywords: Rhenium ; rubidium rhenium halide hydrates ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [Rb2(H2O)2][Re3(μ-Cl)3Br7(H2O)2]2 · H2O, a Mixed Halide-Hydrate with the Anionic Dimer {[Re3(μ-Cl)3Br7(H2O)2]2 · H2O}2-[Rb2(H2O)2][Re3(μ-Cl)3Br7(H2O)2]2 · H2O crystallizes as dark redbrown single crystals from an hydrobromic-acid solution of ReCl3 and RbBr at 0°C. An important feature of the crystal structure (monoclinic, C2/c; a = 1494.61(8); b = 835.71(4); c = 3079.96(19) pm; β = 97.801(4)°; Vm = 573.9(4) cm3mol-1; R = 0.060; Rw = 0.038) is the connection of two anions [Re3(μ-Cl)3Br7(H2O)2]- via a water molecule to dimers, {[Re3(μ-Cl)3Br7(H2O)2]2 · H2O}2-. These dimeric units are contained in slabs that are stacked in the [001] direction and held together by Rb+ cations and crystal water.
    Notes: [Rb2(H2O)2][Re3(μ-Cl)3Br7(H2O)2]2 · H2O kristallisiert in dunklen, rotbraunen Einkristallen aus bromwasserstoffsaurer Lösung von Rheniumtrichlorid und Rubidiumbromid bei 0°C. Ein wichtiges Merkmal der Kristallstruktur (monoklin; C2/c; a = 1494,61(8); b = 835,71(4); c = 3079,96(19) pm; β = 97,801(4)°; Vm = 573,9(4) cm3mol-1; R = 0,060; Rw = 0,038) ist die Verknüpfung zweier Anionen [Re3(μ-Cl)3Br7(H2O)2]- über ein Wassermolekül zu Dimeren {[Re3(μ-Cl)3Br7(H2O)2]2 · H2O}2-. Diese dimeren Baugruppen sind zu Schichtpaketen zusammengefaßt, die längs [001] gestapelt und über die Rb+-Ionen in Gemeinsamkeit mit Kristallwasser verbunden sind.
    Additional Material: 3 Ill.
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  • 9
    ISSN: 0044-2313
    Keywords: Polyphosphides ; Zintl-phases M3X11 (M = Na, K, Rb, Cs; X = P, As) ; P113-, As113- cage anion ; preparation ; vibrational spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry and Structural Chemistry of Phosphides and Polyphosphides. 53. Preparation, Properties, and Vibrational Spectra of the Cage Anions P113- and As113-The Zintl-phases M3X11 (M = Na, K, Rb, Cs; X = P, As) are prepared from the elements or from M3X7 and X. The compounds undergo a first-order phase transition from the crystalline to the plastically crystalline state. Unit cell and space group of both modifications and the transition temperature Tc are determined. The vibrational spectra of the crystalline compounds and the Raman spectrum of the P113- anion in en-solution as well are measured. The assignment of the frequencies is given, based on the 32-D3 symmetry of the X113- cage anion. Normal coordinate analysis is carried out in terms of Cartesian coordinates to avoid the problem of redundancies in using internal coordinates. The force constants [mdyn Å-1] obtained for the characteristic bonds r, s, and t are: fppr = 1.34, fpps = 1.20, fppt = 1.08; fAsAsr = 1.1, fAsAss = 0.91. Normal vibrations and the potential energy distribution (PED) are discussed.
    Notes: Die Zintl-Phasen M3X11 (M = Na, K, Rb, Cs; X = P, As) werden aus den Elementen oder aus M3X7 und X synthetisiert. Die Verbindungen durchlaufen einen Phasenübergang 1. Ordnung vom kristallinen zum plastisch-kristallinen Zustand. Elementarzelle und Raumgruppe beider Modifikationen sowie Übergangstemperaturen Tc wurden bestimmt. Die Schwingungsspektren der kristallinen Verbindungen sowie das Raman-Spektrum des Anions P113- in en-Lösung wurden gemessen. Die Zuordnung der Schwingungsfrequenzen gelingt auf der Basis der Symmetrie 32-D3 der Käfiganionen X113-. Die Normalkoordinatenanalyse erfolgte in kartesischen Koordinaten, wodurch das in inneren Koordinaten auftretende Redundanzproblem vermieden wird. Auf diesem Wege erhaltene Kraftkonstanten [mdyn Å-1] der charakteristischen Bindungen r, s und t sind: fppr = 1, 34, fpps = 1, 20, fppt = 1, 08; fAsAsr = 1, 1, fAsAss = 0, 96, fAsAst = 0, 91. Die Normalschwingungen und die Verteilung der potentiellen Energie (PED) werden diskutiert.
    Additional Material: 4 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 258-261 
    ISSN: 0044-2313
    Keywords: alkaline-earth dihalides ; Ca3Br2CBN ; Sr3Cl2CBN ; preparation ; structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Synthesis of Alkaline-Earth Dihalides and the Structures of Ca3Br2CBN and Sr3Cl2CBNThe reaction of alkaline-earth carbonates with ammonium chloride or bromide yields alkaline-earth dihalides at relatively low temperatures (300°C). Ca3Br2CBN and Sr3Cl2CBN were synthesized in sealed niobium containers at 950°C from the metal, its dihalide, boron nitride and graphite. The crystal structure of Sr3Cl2CBN was refined from single crystal data. Sr3Cl2CBN crystallizes isotypic with Ca3Cl2CBN in the orthorhombic space group Pnma (No. 62) with a = 1448.4(2) pm b = 405.46(5) pm, c = 1170.0(1) pm. The lattice constants of Ca3Br2CBN and Sr3Cl2CBN were determined by orthorhombic indexing of the powder patterns (Ca3Br2CBN: a = 1444.3(2) pm, b = 390.64(6) pm, c = 1139.2(2) pm; Sr3Cl2CBN: a = 1444.0(4) pm, b = 405.27(8) pm, c = 1167.8(2) pm). There was no success in preparing homologues with Barium.
    Notes: Die Umsetzung von Erdalkalimetallcarbonaten mit Ammoniumchlorid oder Ammoniumbromid liefert bei relativ niedrigen Temperaturen (300°C) Erdalkalimetalldihalogenide. Ca3Br2CBN und Sr3Cl2CBN wurden in verschweißten Niobcontainern bei 950°C aus dem Metall, dessen Dihalogenid sowie Bornitrid und Graphit hergestellt. Die Kristallstruktur von Sr3Cl2CBN wurde mit Einkristalldaten verfeinert. Sr3Cl2CBN kristallisiert isotyp zu Ca3Cl2CBN in der orthorhombischen Raumgruppe Pnma (Nr. 62) mit a = 1448,4(2) pm, b = 405,46(5) pm, c = 1170,1(1) pm. Die Gitterkonstanten von Ca3Br2CBN und Sr3Cl2CBN wurden durch orthorhombische Indizierung der Pulverdiagramme bestimmt (Ca3Br2CBN: a = 1444,3(2) pm, b = 390,64(6) pm, c = 1139,2(2) pm; Sr3Cl2CBN: a = 1444,0(4) pm, b = 405,27(8) pm, c = 1167,8(2) pm). Es gelang nicht, Barium-homologe darzustellen.
    Additional Material: 2 Ill.
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