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Andreas Schnepf - One of the best experts on this subject based on the ideXlab platform.

  • ge9 si sime3 3 2 2 a starting point for mixed substituted metalloid germanium Clusters
    Dalton Transactions, 2016
    Co-Authors: Oleksandr Kysliak, Andreas Schnepf
    Abstract:

    Deeper investigations on the silylation reaction of the Ge94− Zintl anion are provided. The reaction of K4Ge9 with two equivalents of ClHyp (Hyp = Si(SiMe3)3) gives the metalloid Cluster Compound [Ge9(Hyp)2]2−. Subsequent reactions with this Compound give access to the first mixed trisubstituted metalloid Cluster [Ge9(Hyp)2(HypPh3)]− (HypPh3 = Si(SiMe3)2(SiPh3)), opening a way to a variety of mixed substituted Ge9 Clusters for future investigations.

  • sn9 si sime3 3 2 2 a metalloid tin Cluster Compound with a sn9 core of oxidation state zero
    ChemInform, 2012
    Co-Authors: Claudio Schrenk, Florian Winter, Rainer Poettgen, Andreas Schnepf
    Abstract:

    [Li(tmeda)2]2{Sn9 [Si(SiMe3)3]2} (tmeda: tetramethylethylenediamine) is synthesized from a mixture of SnCl (obtained by reaction of Sn with HCl at 1240 °C) and LiSi(SiMe3)3 at -78 °C followed by slow warming to room temperature and addition of TMEDA (11% yield).

  • sn9 si sime3 3 2 2 a metalloid tin Cluster Compound with a sn9 core of oxidation state zero
    Inorganic Chemistry, 2012
    Co-Authors: Claudio Schrenk, Florian Winter, Rainer Pottgen, Andreas Schnepf
    Abstract:

    The disproportionation reaction of the subvalent metastable halide SnCl proved to be a powerful synthetic method for the synthesis of metalloid Cluster Compounds of tin. Now we present the synthesis and structural characterization of the anionic metalloid Cluster Compound [Sn9[Si(SiMe3)3]2]2-3 where the oxidation state of the tin atoms is zero. Quantum chemical calculations as well as Mossbauer spectroscopic investigations show that three different kinds of tin atoms are present within the Cluster core. Compound 3 is highly reactive as shown by NMR investigations, thus being a good starting material for further ongoing research on the reactivity of such partly shielded metalloid Cluster Compounds.

  • sn9 si sime3 3 3 and sn8si si sime3 3 3 variations of the e9 cage of metalloid group 14 Clusters
    Inorganic Chemistry, 2012
    Co-Authors: Claudio Schrenk, Marco Neumaier, Andreas Schnepf
    Abstract:

    The disproportionation reaction of the subvalent metastable halide SnBr proved to be a powerful synthetic method for the synthesis of metalloid Cluster Compounds of tin. Hence, the neutral metalloid Cluster Compound Sn10[Si(SiMe3)3]6 (3) was synthesized from the reaction of SnBr with LiSi(SiMe3)3. In the course of the reaction anionic Clusters might also be present, and we now present the first anionic Cluster Compound {Sn8E[Si(SiMe3)3]3}− (E = Si, Sn), where one position in the Cluster core is occupied by a silicon or a tin atom, giving further insight into structural variations of E9 cages in metalloid group 14 Cluster Compounds.

  • sn10 si sime3 3 5 an anionic metalloid tin Cluster from an isolable sni halide solution
    Zeitschrift für anorganische und allgemeine Chemie, 2012
    Co-Authors: Claudio Schrenk, Jens Helmlinger, Andreas Schnepf
    Abstract:

    The disproportionation reaction of the subvalent metastable halide SnBr proved to be a powerful synthetic method for the synthesis of metalloid Cluster Compounds of tin. Hence the neutral metalloid Cluster Compound Sn10[Si(SiMe3)3]6 (1) was synthesized from a reaction of a SnBr emulsion with LiSi(SiMe3)3. Using the phosphane PnBu3 as a donor component during the synthesis of the monohalide solution, an isolable SnI halide solution is obtained. The reaction of such an isolable SnCl solution with LiSi(SiMe3)3 gives the anionic metalloid Cluster Compound {Sn10[Si(SiMe3)3]5}– (5) in 63 % yield, where only five tin atoms are bound to one ligand and where a centaur polyhedral arrangement of the ten tin atoms is present. Due to the open structure 5 might be used for further applications in the field of subsequent build-up reactions.

Claudio Schrenk - One of the best experts on this subject based on the ideXlab platform.

  • sn9 si sime3 3 2 2 a metalloid tin Cluster Compound with a sn9 core of oxidation state zero
    ChemInform, 2012
    Co-Authors: Claudio Schrenk, Florian Winter, Rainer Poettgen, Andreas Schnepf
    Abstract:

    [Li(tmeda)2]2{Sn9 [Si(SiMe3)3]2} (tmeda: tetramethylethylenediamine) is synthesized from a mixture of SnCl (obtained by reaction of Sn with HCl at 1240 °C) and LiSi(SiMe3)3 at -78 °C followed by slow warming to room temperature and addition of TMEDA (11% yield).

  • sn9 si sime3 3 2 2 a metalloid tin Cluster Compound with a sn9 core of oxidation state zero
    Inorganic Chemistry, 2012
    Co-Authors: Claudio Schrenk, Florian Winter, Rainer Pottgen, Andreas Schnepf
    Abstract:

    The disproportionation reaction of the subvalent metastable halide SnCl proved to be a powerful synthetic method for the synthesis of metalloid Cluster Compounds of tin. Now we present the synthesis and structural characterization of the anionic metalloid Cluster Compound [Sn9[Si(SiMe3)3]2]2-3 where the oxidation state of the tin atoms is zero. Quantum chemical calculations as well as Mossbauer spectroscopic investigations show that three different kinds of tin atoms are present within the Cluster core. Compound 3 is highly reactive as shown by NMR investigations, thus being a good starting material for further ongoing research on the reactivity of such partly shielded metalloid Cluster Compounds.

  • sn9 si sime3 3 3 and sn8si si sime3 3 3 variations of the e9 cage of metalloid group 14 Clusters
    Inorganic Chemistry, 2012
    Co-Authors: Claudio Schrenk, Marco Neumaier, Andreas Schnepf
    Abstract:

    The disproportionation reaction of the subvalent metastable halide SnBr proved to be a powerful synthetic method for the synthesis of metalloid Cluster Compounds of tin. Hence, the neutral metalloid Cluster Compound Sn10[Si(SiMe3)3]6 (3) was synthesized from the reaction of SnBr with LiSi(SiMe3)3. In the course of the reaction anionic Clusters might also be present, and we now present the first anionic Cluster Compound {Sn8E[Si(SiMe3)3]3}− (E = Si, Sn), where one position in the Cluster core is occupied by a silicon or a tin atom, giving further insight into structural variations of E9 cages in metalloid group 14 Cluster Compounds.

  • sn10 si sime3 3 5 an anionic metalloid tin Cluster from an isolable sni halide solution
    Zeitschrift für anorganische und allgemeine Chemie, 2012
    Co-Authors: Claudio Schrenk, Jens Helmlinger, Andreas Schnepf
    Abstract:

    The disproportionation reaction of the subvalent metastable halide SnBr proved to be a powerful synthetic method for the synthesis of metalloid Cluster Compounds of tin. Hence the neutral metalloid Cluster Compound Sn10[Si(SiMe3)3]6 (1) was synthesized from a reaction of a SnBr emulsion with LiSi(SiMe3)3. Using the phosphane PnBu3 as a donor component during the synthesis of the monohalide solution, an isolable SnI halide solution is obtained. The reaction of such an isolable SnCl solution with LiSi(SiMe3)3 gives the anionic metalloid Cluster Compound {Sn10[Si(SiMe3)3]5}– (5) in 63 % yield, where only five tin atoms are bound to one ligand and where a centaur polyhedral arrangement of the ten tin atoms is present. Due to the open structure 5 might be used for further applications in the field of subsequent build-up reactions.

  • the formation of a metalloid sn10 si sime3 3 6 Cluster Compound and its relation to the α β tin phase transition
    Dalton Transactions, 2010
    Co-Authors: Claudio Schrenk, Rainer Pottgen, Inga Schellenberg, Andreas Schnepf
    Abstract:

    Very recently it was shown that Sn monohalides can be prepared in preparative scale applying a preparative co-condensation technique. Here, a first reaction of Sn(I)Br is presented leading to the metalloid Cluster Compound Sn10[Si(SiMe3)3]61. This reaction can be seen as a first step to metalloid Cluster Compounds applying the disproportionation reaction of a metastable Sn monohalide. The ten tin atoms in 1 are arranged in the form of a centaur polyhedron, representing a novel structural motif in tin chemistry. The structural and electronic properties of 1 and its relation to the phase transition α↔β tin are discussed with the aid of quantum chemical calculations as well as 119Sn Mossbauer spectroscopy.

Christian Schenk - One of the best experts on this subject based on the ideXlab platform.

  • the formal combination of three singlet biradicaloid entities to a singlet hexaradicaloid metalloid ge14 si sime3 3 5 li thf 2 3 Cluster
    Journal of the American Chemical Society, 2011
    Co-Authors: Christian Schenk, Marco Neumaier, Andreas Kracke, Karin Fink, Adam Kubas, Wim Klopper, Hansgeorg Schnockel, Andreas Schnepf
    Abstract:

    The reaction of GeBr with LiSi(SiMe(3))(3) leads to the metalloid Cluster Compound [(THF)(2)Li](3)Ge(14)[Si(SiMe(3))(3)](5) (1). After the introduction of a first Cluster of this type, in which 14 germanium atoms form an empty polyhedron, [(THF)(2)Li](3)Ge(14)[Ge(SiMe(3))(3)](5) (2), we present here further investigations on 1 to obtain preliminary insight into its chemical and bonding properties. The molecular structure of 1 is determined via X-ray crystal structure solution using synchrotron radiation. The electronic structure of the Ge(14) polyhedron is further examined by quantum chemical calculations, which indicate that three singlet biradicaloid entities formally combine to yield the singlet hexaradicaloid character of 1. Moreover, the initial reactions of 1 after elimination of the [Li(THF)(2)](+) groups by chelating ligands (e.g., TMEDA or 12-crown-4) are presented. Collision induced dissociation experiments in the gas phase, employing FT-ICR mass spectrometry, lead to the elimination of the singlet biradicaloid Ge(5)H(2)[Si(SiMe(3))(3)](2) Cluster. The unique multiradicaloid bonding character of the metalloid Cluster 1 might be used as a model for reactions and properties in the field of surface science and nanotechnology.

  • si sime3 3 6ge18m m zn cd hg neutral metalloid Cluster Compounds of germanium as highly soluble building blocks for supramolecular chemistry
    Dalton Transactions, 2009
    Co-Authors: Florian Henke, Christian Schenk, Andreas Schnepf
    Abstract:

    Very recently it was shown that the metalloid Cluster Compound {Ge9[Si(SiMe3)3]3}−1 can be used for subsequent reactions as the shielding of the Cluster core is rather incomplete. So the reaction of 1 with M+ sources of group 11 metals gives metalloid Cluster Compounds of the formulae {MGe18[Si(SiMe3)3]6}− (M = Au, Ag, Cu). These reactions can be seen as first steps into a supramolecular chemistry with metalloid Cluster Compounds. However, further build-up reactions lead to insoluble products, thus better soluble starting materials are needed for further build-up reactions. Here the first neutral MGe18[Si(SiMe3)3]6 (M = Hg, Cd, Zn) Compounds are described, exhibiting a strongly enhanced solubility in inert solvents. Beside the synthesis, the structural properties as well as the bonding situations in these Cluster Compounds are discussed.

  • otbu 2c6h3 3ge a free germyl cation with aryl ligands
    Dalton Transactions, 2009
    Co-Authors: Christian Schenk, Christian Drost, Andreas Schnepf
    Abstract:

    The reaction of Ar3GeBr (Ar = 2,6-(OtBu)2C6H3), which is the side product of the synthesis of the metalloid germanium Cluster Compound Ge8Ar6, with the silver salt of the weakly coordinating anion (WCA) [Al(ORf)4]− (Rf = C(CF3)3) gives the free germyl cation Ar3Ge+. Quantum chemical calculations open an insight into the bonding situation of this first free cation exhibiting aryl ligands and a first reaction leading to Ar3GeOH is presented.

  • si sime3 3 6ge18m m cu ag au metalloid Cluster Compounds as unusual building blocks for a supramolecular chemistry
    Dalton Transactions, 2008
    Co-Authors: Christian Schenk, Florian Henke, Gustavo Santisoquinones, Ingo Krossing, Andreas Schnepf
    Abstract:

    Very recently it was shown that the metalloid Cluster Compound {Ge9[Si(SiMe3)3]3}−1 can be used for subsequent reactions as the shielding of the Cluster core is rather incomplete. Here further reactions of 1 with M+ sources of group 11 metals are described, leading to metalloid Cluster Compounds of the formula {MGe18[Si(SiMe3)3]6}− (M = Ag, Cu). These reactions can be seen as first steps into a supramolecular chemistry with metalloid Cluster Compounds. Beside this feature, the structural properties as well as the bonding situations in these Cluster Compounds are discussed.

Bernard Malaman - One of the best experts on this subject based on the ideXlab platform.

  • x ray characterization electronic band structure and thermoelectric properties of the Cluster Compound ag2tl2mo9se11
    Inorganic Chemistry, 2014
    Co-Authors: Rabih Al Rahal Al Orabi, P Gougeon, Philippe Gall, Bruno Fontaine, Regis Gautier, Malika Colin, Christophe Candolfi, Anne Dauscher, J Hejtmanek, Bernard Malaman
    Abstract:

    We report on a detailed investigation of the crystal and electronic band structures and of the transport and thermodynamic properties of the Mo-based Cluster Compound Ag2Tl2Mo9Se11. This novel structure type crystallizes in the trigonal space group R3c and is built of a three-dimensional network of interconnected Mo9Se11 units. Single-crystal X-ray diffraction indicates that the Ag and Tl atoms are distributed in the voids of the Cluster framework, both of which show unusually large anisotropic thermal ellipsoids indicative of strong local disorder. First-principles calculations show a weakly dispersive band structure around the Fermi level as well as a semiconducting ground state. The former feature naturally explains the presence of both hole-like and electron-like signals observed in Hall effect. Of particular interest is the very low thermal conductivity that remains quasi-constant between 150 and 800 K at a value of approximately 0.6 W·m–1·K–1. The lattice thermal conductivity is close to its minimu...

  • X‑ray Characterization, Electronic Band Structure, and Thermoelectric Properties of the Cluster Compound Ag2Tl2Mo9Se11
    Inorganic Chemistry, 2014
    Co-Authors: Rabih Al Rahal Al Orabi, P Gougeon, Philippe Gall, Bruno Fontaine, Regis Gautier, Malika Colin, Christophe Candolfi, Anne Dauscher, J Hejtmanek, Bernard Malaman
    Abstract:

    We report on a detailed investigation of the crystal and electronic band structures and of the transport and thermodynamic properties of the Mo-based Cluster Compound Ag2Tl2Mo9Se11. This novel structure type crystallizes in the trigonal space group R3̅c and is built of a three-dimensional network of interconnected Mo9Se11 units. Single-crystal X-ray diffraction indicates that the Ag and Tl atoms are distributed in the voids of the Cluster framework, both of which show unusually large anisotropic thermal ellipsoids indicative of strong local disorder. First-principles calculations show a weakly dispersive band structure around the Fermi level as well as a semiconducting ground state. The former feature naturally explains the presence of both hole-like and electron-like signals observed in Hall effect. Of particular interest is the very low thermal conductivity that remains quasi-constant between 150 and 800 K at a value of approximately 0.6 W·m−1·K−1. The lattice thermal conductivity is close to its minimum possible value, that is, in a regime where the phonon mean free path nears the mean interatomic distance. Such extremely low values likely originate from the disorder induced by the Ag and Tl atoms giving rise to strong anharmonicity of the lattice vibrations. The strongly limited ability of this Compound to transport heat is the key feature that leads to a dimensionless thermoelectric figure of merit ZT of 0.6 at 800 K.

Florian Henke - One of the best experts on this subject based on the ideXlab platform.