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Haas CD, Fischer A, Hauf C, Wieser C, Schmidt AP, Eickerling G, Scheidt EW, Schiffmann JG, Reckeweg O, DiSalvo FJ, Rodewald UC, Pöttgen R, van Wüllen L, Scherer W. The Color of the Elements: A Combined Experimental and Theoretical Electron Density Study of ScB 2 C 2. Angew Chem Int Ed Engl 2019; 58:2360-2364. [PMID: 30570814 DOI: 10.1002/anie.201813102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Indexed: 11/08/2022]
Abstract
The chemical or physical control parameters for the onset of superconductivity in MB2 C2 hetero-graphene materials are unclear. This is mainly due to the almost ubiquitous positional B/C disorder, rendering the description of real structures of borocarbides into one of the most challenging problems in materials science. We will show that high-resolution X-ray diffraction data provides all the essential information to decode even complex coloring problems due to B/C disorder. Electron density studies and subsequent analyses of the fine structure of the Laplacian of the electron density resolves the local electronic structure of ScB2 C2 at sub-atomic resolution and allows for an unequivocal identification of all atoms involved in the coloring scenario. This information could finally be used to identify the electron deficient character of the B/C layers in ScB2 C2 and to synthesize the first bimetallic hetero-metallocene with lithium and scandium atoms embedded in the pentagonal and heptagonal voids, respectively.
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Affiliation(s)
- Christof D Haas
- Institut für Physik, Universität Augsburg, 86135, Augsburg, Germany
| | - Andreas Fischer
- Institut für Physik, Universität Augsburg, 86135, Augsburg, Germany
| | - Christoph Hauf
- Institut für Physik, Universität Augsburg, 86135, Augsburg, Germany
| | - Christian Wieser
- Institut für Physik, Universität Augsburg, 86135, Augsburg, Germany
| | | | - Georg Eickerling
- Institut für Physik, Universität Augsburg, 86135, Augsburg, Germany
| | | | - Jan G Schiffmann
- Institut für Physik, Universität Augsburg, 86135, Augsburg, Germany
| | - Olaf Reckeweg
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853-1301, USA
| | - Francis J DiSalvo
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853-1301, USA
| | - Ute C Rodewald
- Institut für Anorganische und Analytische Chemie, Universität Münster, 48149, Münster, Germany
| | - Rainer Pöttgen
- Institut für Anorganische und Analytische Chemie, Universität Münster, 48149, Münster, Germany
| | - Leo van Wüllen
- Institut für Physik, Universität Augsburg, 86135, Augsburg, Germany
| | - Wolfgang Scherer
- Institut für Physik, Universität Augsburg, 86135, Augsburg, Germany
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Haas CD, Fischer A, Hauf C, Wieser C, Schmidt AP, Eickerling G, Scheidt EW, Schiffmann JG, Reckeweg O, DiSalvo FJ, Rodewald UC, Pöttgen R, van Wüllen L, Scherer W. The Color of the Elements: A Combined Experimental and Theoretical Electron Density Study of ScB2
C2. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201813102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Christof D. Haas
- Institut für Physik; Universität Augsburg; 86135 Augsburg Germany
| | - Andreas Fischer
- Institut für Physik; Universität Augsburg; 86135 Augsburg Germany
| | - Christoph Hauf
- Institut für Physik; Universität Augsburg; 86135 Augsburg Germany
| | - Christian Wieser
- Institut für Physik; Universität Augsburg; 86135 Augsburg Germany
| | | | - Georg Eickerling
- Institut für Physik; Universität Augsburg; 86135 Augsburg Germany
| | | | | | - Olaf Reckeweg
- Department of Chemistry and Chemical Biology; Cornell University; Ithaca NY 14853-1301 USA
| | - Francis J. DiSalvo
- Department of Chemistry and Chemical Biology; Cornell University; Ithaca NY 14853-1301 USA
| | - Ute C. Rodewald
- Institut für Anorganische und Analytische Chemie; Universität Münster; 48149 Münster Germany
| | - Rainer Pöttgen
- Institut für Anorganische und Analytische Chemie; Universität Münster; 48149 Münster Germany
| | - Leo van Wüllen
- Institut für Physik; Universität Augsburg; 86135 Augsburg Germany
| | - Wolfgang Scherer
- Institut für Physik; Universität Augsburg; 86135 Augsburg Germany
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Benndorf C, de Oliveira M, Doerenkamp C, Haarmann F, Fickenscher T, Kösters J, Eckert H, Pöttgen R. 11B and 89Y solid state MAS NMR spectroscopic investigations of the layered borides YTB 4 (T = Mo, W, Re). Dalton Trans 2019; 48:1118-1128. [PMID: 30605201 DOI: 10.1039/c8dt04444a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The YCrB4 type borides YTB4 (T = Mo, W, Re) were synthesized from the elements by arc-melting and subsequent annealing. The structures were refined from single crystal X-ray diffractometer data: Pbam, a = 602.84(8), b = 1164.5(1), c = 361.20(4) pm, wR2 = 0.0404, 624 F2 values, 26 variables for YMoB4, a = 603.00(7), b = 1165.1(1), c = 360.63(6) pm, wR2 = 0.0487, 474 F2 values, 26 variables for YWB4, and a = 596.67(6), b = 1154.4(1), c = 360.21(4) pm, wR2 = 0.0465, 544 F2 values, 26 variables for YReB4. The boron atoms build up planar networks which are a tessellation of slightly distorted pentagons and heptagons. Adjacent networks coordinate the transition metal and yttrium atoms in the form of pentagonal and heptagonal prisms, respectively. The four crystallographically distinct boron sites are differentiated by high-resolution 11B solid state isotropic magnetic shifts and nuclear electric quadrupolar coupling constants. Partial site assignments are possible based on comparisons with electric field gradient calculations using the WIEN2k code. 89Y MAS NMR spectroscopic studies suggest substantially weaker Knight shift contributions to the resonance frequencies when compared to other intermetallic yttrium compounds, including other ternary yttrium boride compounds measured previously.
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Affiliation(s)
- Christopher Benndorf
- Institut für Mineralogie, Kristallographie und Materialwissenschaft, Universität Leipzig, Scharnhorststrasse 20, D-04275 Leipzig, Germany
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Lassoued S, Boucher B, Boutarfaia A, Gautier R, Halet JF. The coloring problem in the solid-state metal boride carbide ScB2C2: a theoretical analysis. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2016. [DOI: 10.1515/znb-2016-0056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The electronic properties of the layered ternary metal boride carbide ScB2C2, the structure of which consists of B/C layers made of fused five- and seven-membered rings alternating with scandium sheets, are analyzed. In particular, the respective positions of the B and C atoms (the so-called coloring problem) are tackled using density functional theory, quantum theory of atoms in molecules, and electron localizability indicator calculations. Results reveal that (i) the most stable coloring minimizes the number of B–B and C–C contacts and maximizes the number of boron atoms in the heptagons, (ii) the compound is metallic in character, and (iii) rather important covalent bonding occurs between the metallic sheets and the boron–carbon network.
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Affiliation(s)
| | | | - Ahmed Boutarfaia
- Faculté des Mathématiques et des Sciences de la Matière, Université Kasdi Merbah-Ouargla , Ouargla, Algeria
| | - Régis Gautier
- Institut des Sciences Chimiques de Rennes , UMR 6226 CNRS, Ecole Nationale Supérieure de Chimie de Rennes, Université de Rennes 1 , F-35042 Rennes, France
| | - Jean-François Halet
- Institut des Sciences Chimiques de Rennes , UMR 6226 CNRS, Ecole Nationale Supérieure de Chimie de Rennes, Université de Rennes 1 , F-35042 Rennes, France
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