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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Catalysis letters 49 (1997), S. 199-205 
    ISSN: 1572-879X
    Keywords: decomposition ; hydrolysis ; heterogeneous catalysis ; dichlorodifluoromethane ; CFC-12 ; zirconia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The hydrolytic decomposition of dichlorodifluoromethane (CFC-12) on various modified zirconium oxide surfaces has been studied. The reaction was carried out under flow conditions at 500°C. Complete CFC-12 conversion and long-time stability of the catalysts were achieved accompanied by a limitation of the undesired CFC-13 formation. A maximum CFC-12 conversion was observed on catalysts of sulfated zirconia or zirconia obtained from temperature-controlled calcination of zirconium oxide hydrate. The reaction depends on the presence or in situ formation of Brønsted acid sites. FTIR-photoacoustic measurements were performed on pyridine complexes chemisorbed on the catalyst surface in order to analyze the changes in the catalyst's acidity. The effects of the temperature and water in the reaction gas on the catalyzed decomposition of CFC-12 are examined.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 675-678 
    ISSN: 0044-2313
    Keywords: Lithium Hydrogensulfate ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of LiHSO4Single crystals of the new compound LiHSO4 are synthezised from the system Lithiumsulfate/Sulfuric acid. The up to day not determined structure of the title compound is monoclinic, space group P21/c with the lattice constants a = 5.234(2), b = 7.322(1) and c = 8.363(1) Å, b̃ = 90.02(2)°. The volume of the unit cell has been determined to V = 320.5 Å3, the number of formula units to Z = 4 and the density to Dx = 2.156 g cm-3.There are crystallographically identical SO3(OH)- and LiO4-tetrahedra in the structure. Every tetraheda is linked to four different tetrahedra of the other sort. Two neighboured LiO4 terahedra form a common edge. In that way layers are formed running parallel the yz-plane. These layers are connected over hydrogen bonds.
    Notes: Im System Lithiumsulfat/Schwefelsäure sind gut ausgebildete Einkristalle von LiHSO4 erhalten worden. Die Verbindung kristallisiert in der monoklinen Raumgruppe P21/c mit den Gitterkonstanten a = 5,234(2), b = 7,322(1) und c = 8,363(1) Å, b̃ = 90,02(2)°. Das Volumen der Elementarzelle wurde zu V = 320,5 Å3, die Zahl der Formeleinheiten zu Z = 4 und die Dichte zu Dx = 2,156 g cm-3 bestimmt.Es liegen kristallographisch identische SO3(OH)- und LiO4-Tetraeder vor. Jedes dieser Tetraeder ist mit jeweils vier verschiedenen Tetraedern der anderen Sorte verbunden. Zwei benachbarte LiO4-Tetraeder bilden jeweils eine gemeinsame Kante aus. Auf diese Weise bilden sich Schichten aus, die parallel der yz-Ebene verlaufen und über Wasserstoffbrückenbindungen miteinander verbunden sind.
    Additional Material: 2 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 1617-1624 
    ISSN: 0044-2313
    Keywords: Sodium hydrogensulfate ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Structure of New Sodium Hydrogen Sulfates Na(H3O)(HSO4)2, Na2(HSO4)2(H2SO4), and Na(HSO4)(H2SO4)2Three acidic sodium sulfates have been synthesized from the system sodium sulfate/sulfuric acid and have been crystallographically characterized. Na(H3O)(HSO4)2 (A) crystallizes in the space group P21/c with the unit cell parameters a = 6.974(2), b = 13.086(2), c = 8.080(3) Å, α = 105.90(4)°, V = 709.1 Å3, Z = 4. Na2(HSO4)2(H2SO4) (B) is orthorhombic (space group Pna21) with the unit cell parameters a = 9.970(2), b = 6.951(1), c = 13.949(3) Å, V = 966.7 Å3 and Z = 4. Na(HSO4)(H2SO4)2 (C) crystallizes in the triclinic space group P1 with the unit cell parameters a = 5.084(1), b = 8.746(1), c = 11.765(3) Å, α = 68.86(2)°, β = 88.44(2)°, γ = 88.97(2)°, V = 487.8 Å3 and Z = 2.All three compounds contain SO4 tetrahedra as HSO4- anions and additionally in B and C in form of H2SO4 molecules. The ratio H:SO4 determines the connectivity degree in the hydrogen bond system. In A, there are zigzag chains and dimers additionally connected via oxonium ions. Complex chains consisting of cyclic trimers (two HSO4- and one H2SO4) are present in B. In structure C, several parallel chains are connected to columns due to the greater content of H2SO4.Sodium cations show a distorted octahedral coordination by oxygen in all three structures, the NaO6 octahedra being “isolated” (connected via SO4 tetrahedra only) in A. Pairs of octahedra with common edge form Na2O10 dimeric units in C. Such double octahedra are connected via common corners forming zigzag chains in B.
    Notes: Aus dem System Natriumsulfat/Schwefelsäure konnten drei saure Sulfate synthetisiert und strukturell charakterisiert werden. Na(H3O)(HSO4)2 (A) kristallisiert in der monoklinen Raumgruppe P21/c mit den Gitterkonstanten a = 6,974(2), b = 13,086(2), c = 8,080(3) Å, β = 105,90(4)°, V = 709,1 Å3 und Z = 4. Na2(HSO4)2(H2SO4) (B) ist orthorhombisch (Pna21) mit den Gitterkonstanten a = 9,970(2), b = 6,951(1), c = 13,949(3) Å, V = 966,7 Å3 und Z = 4. Na(HSO4)(H2SO4)2 (C) kristallisiert in der triklinen Raumgruppe P1 mit a = 5,084(1), b = 8,746(1), c = 11,765(3) Å, α = 68,86(2)°, β = 88,44(2)°, γ = 88,97(2)°, V = 487,8 Å3 und Z = 2.In allen drei Verbindungen liegen SO4-Tetraeder in Form von HSO4--Anionen und zusätzlich in B und C in Form neutraler H2SO4-Moleküle vor. Das Verhältnis H:SO4 bestimmt den Vernetzungsgrad im Wasserstoffbrückenbindungssystem. In A liegen HSO4-Dimere neben Zick-Zack-Ketten vor, die zusätzlich über Oxoniumionen miteinander vernetzt sind. Für die Struktur von B ist die Bildung von Ketten, die aus cyclischen Trimeren (zwei HSO4- und ein H2SO4) bestehen, charakteristisch. Durch den größeren Anteil an H2SO4 sind in C mehrere parallele Ketten zu Säulen verbunden.Natrium ist in allen drei Strukturen verzerrt oktaedrisch von Sauerstoff koordiniert, wobei in A “isolierte” (nur über SO4-Tetraeder verbundene) NaO6-Oktaeder vorliegen. In C werden zwei Oktaeder über eine Kante zu Na2O10-Doppeloktaedern verbunden. Solche Doppeloktaeder werden in B über Ecken zu Zick-Zack-Ketten verknüpft.
    Additional Material: 3 Ill.
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  • 4
    ISSN: 0044-2313
    Keywords: Hydrogen sulfate of sodium and lithium ; synthesis ; crystal structure ; disordered hydrogen atoms ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydrogen Sulfates with Disordered Hydrogen Atoms - Synthesis and Structure of Li[H(HSO4)2](H2SO4)2 and Refinement of the Structure of α-NaHSO4The structure of Li[H(HSO4)2](H2SO4)2 has been determined for the first time whereas the structure of α-NaHSO4 has been refined, so that direct determination of the hydrogen positions was possible. Both compounds crystallize triclinic in the space group P1 with the lattice constants a = 6.708(2), b = 6.995(1), c = 7.114(1) Å, α = 75.53(1), β = 84.09(2) and γ = 87.57(2)° (Z = 4) for α-NaHSO4 and a = 4.915(1), b = 7.313(1), c = 8.346(2) Å, α = 82.42(3), β = 86.10(3) and γ = 80.93(3)° (Z = 1) for Li[H(HSO4)2](H2SO4)2. In both compounds there are disordered hydrogen positions.In the structure of α-NaHSO4 there are two crystallographically different HSO4- tetrahedra and two different coordinated Na atoms. The system of hydrogen bonds can be described by chains in [0-11] direction. The disordering of the H atoms reduces the differences between the S—O and S—OH distances (1.45 and 1.50 Å) while in the ordered HSO4 unit “regular” bond lengths are observed (1.45 und 1,57 Å).In the structure of Li[H(HSO4)2](H2SO4)2 there are two crystallographically different SO4-tetrahedra. The first one belongs to the [H(HSO4)2]- unit while the second one represents H2SO4 molecules. The H atom which is located nearby the symmetry centre and connects two HSO4 units by a short O…O distance of 2.44 Å. Li is located on a symmetry centre and is slightly distorted octahedrally coordinated by oxygen atoms of six different SO4 tetrahedra. The system of hydrogen bonds can be regarded as consisting of double layers parallel to the xy-plane.
    Notes: Von Li[H(HSO4)2](H2SO4)2 konnte die Struktur erstmals bestimmt und für α-NaHSO4 so verfeinert werden, daß die direkte Bestimmung der Wasserstoffpositionen möglich wurde. Beide Verbindungen kristallisieren in der triklinen Raumgruppe P1 mit den Gitterkonstanten a = 6,708(2), b = 6,995(1), c = 7,114(1) Å, α = 75,53(1), β = 84,09(2) und γ = 87,57(2)° (Z = 4) für α-NaHSO4 sowie a = 4,915(1), b = 7,313(1), c = 8,346(2) Å, α = 82,42(3), β = 86,10(3) und γ = 80,93(3)° (Z = 1) für Li[H(HSO4)2](H2SO4)2. Beiden Verbindungen ist gemeinsam, daß fehlgeordnete Wasserstoffpositionen vorliegen.In der Struktur von α-NaHSO4 liegen zwei kristallographisch unterschiedliche HSO4--Tetraeder und zwei verschieden koordinierte Na-Atome vor. Das Wasserstoffbrückensystem läßt sich durch Ketten mit Seitenabzweigungen beschreiben. Die Fehlordnung der H-Atome einer HSO4-Gruppe nivelliert die Unterschiede zwischen den S—O- und S—OH-Abständen (1,45 und 1,50 Å), während in der geordneten HSO4-Gruppe die üblicherweise vorliegenden Bindungslängen gefunden werden (1,45 und 1,57 Å).In der Struktur des Li[H(HSO4)2](H2SO4)2 treten zwei kristallographisch unterschiedliche SO4-Tetraeder auf. Dabei gehört eines zu der [H(HSO4)2]--Einheit während das zweite das H2SO4-Molekül darstellt. Das in der Nähe eines Symmetriezentrums liegende H-Atom verbindet zwei HSO4-Gruppen mit einem kurzen O…O-Abstand von 2,44 Å. Li liegt in einem Symmetriezentrum und wird durch Sauerstoff von sechs verschiedenen SO4-Tetraedern schwach verzerrt oktaedrisch koordiniert. Das System der Wasserstoffbindungen läßt sich als Doppelschicht beschreiben.
    Additional Material: 3 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1921-1924 
    ISSN: 0044-2313
    Keywords: Potassium hydrogen sulfate ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Potassium Hydrogensulfate, K(H3O)(HSO4)2  -  Synthesis and StructureSingle crystals of the new compound K(H3O)(SO4)2 are synthesized from the system potassium sulfate/sulfuric acid. The up to day not described compound crystallizes in the monoclinic space group P21/c with the unit cell parameters a = 7.203(1) b = 13.585(2) and c = 8.434(1) Å, β = 105.54(1)°, V = 795.1 Å3, Z = 4 and Dx = 2.107 g · cm-3.There are two crystallographically different tetrahedral SO3(OH) anions. The first kind S1 tetrahedra forms dimers, whereas the second kind S2 forms infinite chains bonded via hydrogen bridges. The S1 dimers are linked to the S2 chains via oxonium ions (hydrogen bonds).Potassium is coordinated by 8 oxygen atoms which belong to four different SO3(OH) tetrahedra. These potassium oxygen polyhedra are connected by common edges forming chains running parallel z.
    Notes: Im System Kaliumsulfat/Schwefelsäure ist ein neues, bisher nicht beschriebenes saures Sulfat der Zusammensetzung K(H3O)(HSO4)2 synthetisiert worden. Die Verbindung kristallisiert in der monoklinen Raumgruppe P21/c mit den Gitterkonstanten a = 7,203(1), b = 13,585(2) und c = 8,434(1) Å, β = 105,54(1)°, V = 795,1 Å3, Z = 4 und Dx = 2,107 g · cm-3.Es liegen zwei kristallographisch verschiedene SO3(OH)-Tetraeder vor. Die eine Tetraedersorte (S1) bildet Dimere aus, während die Tetraeder der Sorte S2 über Wasserstoffbrücken verbundene Ketten bilden. Die Dimeren der S1-Tetraeder sind mit den unendlichen Ketten der S2-Tetraeder über Oxoniumionen (Wasserstoffbrücken) verbrückt.Kalium ist von 8 Sauerstoffatomen, die vier verschiedenen SO3(OH) Tetraedern angehören, koordiniert. Die Kalium-Sauerstoff-Polyeder sind über gemeinsame Kanten miteinander verknüpft und bilden Ketten parallel der z-Achse.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 1266-1269 
    ISSN: 0044-2313
    Keywords: Lithium hydrogen sulfate dihydrogen sulfate ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Lithium Hydrogen Sulfate, Li2(HSO4)2(H2SO4) - Synthesis and Crystal StructureThe title compound crystallizes in good shaped single crystals from the system lithium sulfate/sulfuric acid in the orthorhombic space group Pccn, unit cell parameters a = 17.645(4), b = 5.378(1), c = 10.667(3) Å. V = 1 012.2 Å3, Z = 4, Dx = 2.009 g cm-3.There are two types of SO4 tetrahedra, SO3(OH) and SO2(OH)2, connected via hydrogen bonds forming layers parallel to the xy-plane. The layers are linked by Li atoms, which are tetrahedral coordinated by O atoms coming two by two from neighboured layers.
    Notes: Die Titelverbindung kristallisiert aus dem System Lithiumsulfat/Schwefelsäure in Form gut ausgebildeter Einkristalle in der orthorhombischen Raumgruppe Pccn, Gitterkonstanten a = 17,645(4), b = 5,378(1), c = 10,667(3) Å, V = 1 012,2 Å3, Z = 4, Dx = 2,009 g cm-3.Es liegen zwei Sorten von SO4-Tetraedern, SO3(OH) und SO2(OH)2, vor, die mittels Wasserstoffbrücken zu Schichten parallel der xy-Ebene verknüpft sind. Die Schichten werden über Li-Atome miteinander verbunden. Lithium wird dabei von jeweils zwei Sauerstoffatomen benachbarter Schichten tetraedrisch koordiniert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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