Hlukhyy, Viktor ; Raif, Fabian ; Claus, Peter ; Fässler, Thomas Friedrich (2008)
Polar Intermetallic Compounds as Catalysts for Hydrogenation Reactions: Synthesis, Structures, Bonding, and Catalytic Properties of Ca₁₋ₓSrₓNi₄Sn₂ (x=0.0, 0.5, 1.0) and Catalytic Properties of Ni₃Sn and Ni₃Sn₂.
In: Chemistry - A European Journal, 14 (12)
doi: 10.1002/chem.200701547
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The potential of polar intermetallic compounds to catalyze hydrogenation reactions was evaluated. The novel compounds CaNi₄Sn₂, SrNi₄Sn₂, and Ca0.5Sr0.5Ni₄Sn₂ were tested as unsupported alloys in the liquid-phase hydrogenation of citral. Depending on the reaction conditions, conversions of up to 21.0 % (253 K and 9.0 MPa hydrogen pressure) were reached. The binary compounds Ni3Sn and Ni₃Sn₂ were also tested in citral hydrogenation under the same conditions. These materials gave conversions of up to 37.5 %. The product mixtures contained mainly geraniol, nerol, citronellal, and citronellol. The isotypic stannides CaNi₄Sn₂, Ca0.5Sr0.5Ni₄Sn₂, and SrNi₄Sn₂ were obtained by melting mixtures of the elements in an arc-furnace under an argon atmosphere. Single crystals were synthesized in tantalum ampoules using special temperature modes. The novel structures were established by single-crystal X-ray diffraction. They crystallize in the tetragonal space group I4/mcm with parameters: a=7.6991(7), c=7.8150(8) Å, wR2=0.034, 162 F2 values, 14 variable parameters for CaNi4Sn2; a=7.7936(2), c=7.7816(3) Å, wR2=0.052, 193 F2 values, 15 variable parameters for Ca0.5Sr0.5Ni4Sn2; and a=7.8916(4), c=7.7485(5) Å, wR2=0.071, 208 F2 values, 14 variable parameters for SrNi4Sn2. The Ca1-ₓSrₓNi₄Sn₂ (x=0.0, 0.5, 1.0) structures can be represented as a stuffed variant of the CuAl₂ type by the formal insertion of one-dimensional infinite Ni-cluster chains [Ni₄] into the Ca(Sr)Sn₂ substructure. The Ni and Sn atoms form a three-dimensional infinite [Ni₄Sn₂] network in which the Ca or Sr atoms fill distorted octagonal channels. The densities of states obtained from TB-LMTO-ASA calculations show metallic character for both compounds.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2008 |
| Autor(en): | Hlukhyy, Viktor ; Raif, Fabian ; Claus, Peter ; Fässler, Thomas Friedrich |
| Art des Eintrags: | Bibliographie |
| Titel: | Polar Intermetallic Compounds as Catalysts for Hydrogenation Reactions: Synthesis, Structures, Bonding, and Catalytic Properties of Ca₁₋ₓSrₓNi₄Sn₂ (x=0.0, 0.5, 1.0) and Catalytic Properties of Ni₃Sn and Ni₃Sn₂ |
| Sprache: | Englisch |
| Publikationsjahr: | 18 April 2008 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Chemistry - A European Journal |
| Jahrgang/Volume einer Zeitschrift: | 14 |
| (Heft-)Nummer: | 12 |
| DOI: | 10.1002/chem.200701547 |
| Kurzbeschreibung (Abstract): | The potential of polar intermetallic compounds to catalyze hydrogenation reactions was evaluated. The novel compounds CaNi₄Sn₂, SrNi₄Sn₂, and Ca0.5Sr0.5Ni₄Sn₂ were tested as unsupported alloys in the liquid-phase hydrogenation of citral. Depending on the reaction conditions, conversions of up to 21.0 % (253 K and 9.0 MPa hydrogen pressure) were reached. The binary compounds Ni3Sn and Ni₃Sn₂ were also tested in citral hydrogenation under the same conditions. These materials gave conversions of up to 37.5 %. The product mixtures contained mainly geraniol, nerol, citronellal, and citronellol. The isotypic stannides CaNi₄Sn₂, Ca0.5Sr0.5Ni₄Sn₂, and SrNi₄Sn₂ were obtained by melting mixtures of the elements in an arc-furnace under an argon atmosphere. Single crystals were synthesized in tantalum ampoules using special temperature modes. The novel structures were established by single-crystal X-ray diffraction. They crystallize in the tetragonal space group I4/mcm with parameters: a=7.6991(7), c=7.8150(8) Å, wR2=0.034, 162 F2 values, 14 variable parameters for CaNi4Sn2; a=7.7936(2), c=7.7816(3) Å, wR2=0.052, 193 F2 values, 15 variable parameters for Ca0.5Sr0.5Ni4Sn2; and a=7.8916(4), c=7.7485(5) Å, wR2=0.071, 208 F2 values, 14 variable parameters for SrNi4Sn2. The Ca1-ₓSrₓNi₄Sn₂ (x=0.0, 0.5, 1.0) structures can be represented as a stuffed variant of the CuAl₂ type by the formal insertion of one-dimensional infinite Ni-cluster chains [Ni₄] into the Ca(Sr)Sn₂ substructure. The Ni and Sn atoms form a three-dimensional infinite [Ni₄Sn₂] network in which the Ca or Sr atoms fill distorted octagonal channels. The densities of states obtained from TB-LMTO-ASA calculations show metallic character for both compounds. |
| Freie Schlagworte: | calcium • crystal structure • hydrogenation catalysts • intermetallic compounds • strontium |
| Zusätzliche Informationen: | Published Online: 20. Februar 2008 |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Ernst-Berl-Institut > Fachgebiet Technische Chemie > Technische Chemie II 07 Fachbereich Chemie > Ernst-Berl-Institut > Fachgebiet Technische Chemie |
| Hinterlegungsdatum: | 20 Mär 2009 09:00 |
| Letzte Änderung: | 05 Mär 2013 09:18 |
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