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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

Hlukhyy, Viktor ; Raif, Fabian ; Claus, Peter ; Fässler, Thomas Friedrich :
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.
[Online-Edition: http://dx.doi.org/10.1002/chem.200701547]
In: Chemistry - A European Journal, 14 (12) pp. 3737-3744.
[Artikel], (2008)

Offizielle URL: http://dx.doi.org/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.

Typ des Eintrags: Artikel
Erschienen: 2008
Autor(en): Hlukhyy, Viktor ; Raif, Fabian ; Claus, Peter ; Fässler, Thomas Friedrich
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
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.

Titel der Zeitschrift, Zeitung oder Schriftenreihe: Chemistry - A European Journal
Band: 14
(Heft-)Nummer: 12
Freie Schlagworte: calcium • crystal structure • hydrogenation catalysts • intermetallic compounds • strontium
Fachbereich(e)/-gebiet(e): Fachbereich Chemie
Fachbereich Chemie > Technische Chemie > Technische Chemie II
Fachbereich Chemie > Technische Chemie
Hinterlegungsdatum: 20 Mär 2009 09:00
Offizielle URL: http://dx.doi.org/10.1002/chem.200701547
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Published Online: 20. Februar 2008

ID-Nummer: 10.1002/chem.200701547
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