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Carrillo-Cabrera W, Hübner JM, Freccero R, Jung W, Baitinger M, Grin J, Schwarz U. Na 2B 6Si 2: A Prototype Silico-boride with Closo (B 6) 2- Clusters. J Am Chem Soc 2024; 146:24759-24763. [PMID: 39186750 PMCID: PMC11403601 DOI: 10.1021/jacs.4c08745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
The compound Na2B6Si2 was synthesized under high-pressure, high-temperature conditions at pressures ranging from 6 to 9.5 GPa and temperatures from 1070 to 1270 K before quenching to room temperature followed by slow decompression. The crystal structure was determined from microcrystals using precession-assisted electron diffraction tomography, validated by dynamical refinement and full-profile refinements using optimized coordinates from quantum chemical calculations (space group R3̅m, Pearson symbol hR30, a = 5.0735(1) Å and c = 16.0004(7) Å). The atomic arrangement consists of a unique framework formed by electron-precise octahedral closo (B6)2- clusters connected via ethane-like (Si2)0 dumbbells. The Na+ cations occupy cavities in the hierarchical variation of a Heusler-type framework. The balance (Na+)2([B6]2-)(Si0)2 reveals an electron precise Zintl-Wade phase, which is in line with electronic band structure calculations predicting semiconducting behavior.
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Affiliation(s)
- Wilder Carrillo-Cabrera
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Julia-Maria Hübner
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, District of Columbia 20015, United States
- Faculty of Chemistry and Food Chemistry, TUD Dresden University of Technology, 01062 Dresden, Germany
| | - Riccardo Freccero
- Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova, Via Dodecaneso 31, I-16146 Genova, Italy
| | - Walter Jung
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Michael Baitinger
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Juri Grin
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Ulrich Schwarz
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany
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2
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Yu CC, Prots Y, Ormeci A, Krnel M, Schmidt M, Akselrud L, Wagner FR, Grin Y, Baitinger M. Ordering by cation replacement in the system Na 2-xLi xGa 7. Dalton Trans 2024; 53:908-916. [PMID: 38126575 DOI: 10.1039/d3dt03628f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Samples of the pseudo-binary system Na2-xLixGa7 (x ≤ 1) were synthesized from the elements at 300 °C in sealed Ta ampoules or by the reaction of Na2Ga7 with LiCl. The peritectic formation temperature decreases with increasing Li content from 501(2) °C (x = 0) to 489(2) °C (x = 1). The boundary compositions Na2Ga7 and Na1Li1Ga7 crystallize with different structure types related by a group-subgroup relation. While the Na-rich compositions (x ≤ 0.5) represent a substitutional solid solution (space group Pnma), the Li-rich compositions feature an unconventional replacement mechanism in which Li atoms occupying interstitial positions induce vancancies at the Na positions (space group Cmce). The crystal structure of Na1Li1Ga7 (a = 8.562(1) Å, b = 14.822(2) Å, c = 11.454(2) Å; Z = 8) was determined from X-ray single-crystal diffraction data, and reveals an anionic framework comprising 12-bonded Ga12 icosahedra and 4-bonded Ga atoms, with alkali-metal atoms occupying channels and cavities. The arrangement of cations makes NaLiGa7 a new structure type within the MgB12Si2 structure family. Band structure calculations for the composition NaLiGa7 predict semiconducting behavior consistent with the balance [Na+]2[Li+]2[(Ga12)2-][Ga-]2, considering closo Wade clusters [(12b)Ga12]2- and Zintl anions [(4b)Ga]-. Susceptibility measurements indicate temperature-independent diamagnetic behavior.
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Affiliation(s)
- Chia-Chi Yu
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany.
| | - Yurii Prots
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany.
| | - Alim Ormeci
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany.
| | - Mitja Krnel
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany.
| | - Marcus Schmidt
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany.
| | - Lev Akselrud
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany.
- Ivan Franko Lviv National University, Kyryla i Mefodia St. 6, 29005 Lviv, Ukraine
| | - Frank R Wagner
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany.
| | - Yuri Grin
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany.
| | - Michael Baitinger
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany.
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Morito H, Ikeda T, Katsura Y, Yamane H. Na 3MgB 37Si 9: an icosa-hedral B 12 cluster framework containing {Si 8} units. Acta Crystallogr E Crystallogr Commun 2022; 78:203-206. [PMID: 35145751 PMCID: PMC8819436 DOI: 10.1107/s2056989022000494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/13/2022] [Indexed: 11/30/2022]
Abstract
Single crystals of a novel sodium-magnesium boride silicide, Na3MgB37Si9 [a = 10.1630 (3) Å, c = 16.5742 (6) Å, space group R m (No. 166)], were synthesized by heating a mixture of Na, Si and crystalline B with B2O3 flux in Mg vapor at 1373 K. The Mg atoms in the title compound are located at an inter-stitial site of the Dy2.1B37Si9-type structure with an occupancy of 0.5. The (001) layers of B12 icosa-hedra stack along the c-axis direction with shifting in the [-a/3, b/3, c/3] direction. A three-dimensional framework structure of the layers is formed via B-Si bonds and {Si8} units of [Si]3-Si-Si-[Si]3.
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Affiliation(s)
- Haruhiko Morito
- Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Takuji Ikeda
- Research Institute for Chemical Process Technology, National Institute of Advanced Industrial Science and Technology, 4-2-1, Nigatake, Miyagino-ku, Sendai 983-8551, Japan
| | - Yukari Katsura
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Hisanori Yamane
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku, University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
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Babizhetskyy V, Levytskyi V, Jardin R, Bauer J, Guérin R, Gautier R, Fontaine B, Halet J. Rare‐earth Metal Borosilicides
R
9
Si
15–
x
B
3
(
R
= Tb, Yb): New Ordered Structures Derived from the AlB
2
Structure Type. Z Anorg Allg Chem 2020. [DOI: 10.1002/zaac.202000046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Volodymyr Babizhetskyy
- Department of Inorganic Chemistry Ivan Franko National University of Lviv Kyryla & Mefodiya Str. 6 UA‐79005 Lviv Ukraine
| | - Volodymyr Levytskyi
- Department of Inorganic Chemistry Ivan Franko National University of Lviv Kyryla & Mefodiya Str. 6 UA‐79005 Lviv Ukraine
- Institute of Experimental Physics TU Bergakademie Freiberg Leipziger Str. 23 09596 Freiberg Germany
| | - Régis Jardin
- Institut des Sciences Chimiques de Rennes‐UMR 6226 Univ Rennes, CNRS, Ecole Nationale Supérieure de Chimie de Rennes 35000 Rennes France
| | - Josef Bauer
- Institut des Sciences Chimiques de Rennes‐UMR 6226 Univ Rennes, CNRS, Ecole Nationale Supérieure de Chimie de Rennes 35000 Rennes France
| | - Roland Guérin
- Institut des Sciences Chimiques de Rennes‐UMR 6226 Univ Rennes, CNRS, Ecole Nationale Supérieure de Chimie de Rennes 35000 Rennes France
| | - Régis Gautier
- Institut des Sciences Chimiques de Rennes‐UMR 6226 Univ Rennes, CNRS, Ecole Nationale Supérieure de Chimie de Rennes 35000 Rennes France
| | - Bruno Fontaine
- Institut des Sciences Chimiques de Rennes‐UMR 6226 Univ Rennes, CNRS, Ecole Nationale Supérieure de Chimie de Rennes 35000 Rennes France
| | - Jean‐François Halet
- Institut des Sciences Chimiques de Rennes‐UMR 6226 Univ Rennes, CNRS, Ecole Nationale Supérieure de Chimie de Rennes 35000 Rennes France
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Hillebrecht H, Vojteer N, Sagawe V, Hofmann K, Albert B. Synthesis and Characterization of Li-containing Boron Carbide r
-Li~1
B13
C2. Z Anorg Allg Chem 2018. [DOI: 10.1002/zaac.201800289] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Harald Hillebrecht
- Institut für Anorganische und Analytische Chemie; Albert-Ludwigs-Universität Freiburg; 79104 Freiburg Germany
- Freiburger Materialforschungszentrum FMF; Stefan-Meier-Str. 25 79104 Freiburg Germany
| | - Natascha Vojteer
- Institut für Anorganische und Analytische Chemie; Albert-Ludwigs-Universität Freiburg; 79104 Freiburg Germany
| | - Vanessa Sagawe
- Institut für Anorganische und Analytische Chemie; Albert-Ludwigs-Universität Freiburg; 79104 Freiburg Germany
| | - Kathrin Hofmann
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie; Technische Universität Darmstadt; Alarich-Weiss-Str. 12 64287 Darmstadt Germany
| | - Barbara Albert
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie; Technische Universität Darmstadt; Alarich-Weiss-Str. 12 64287 Darmstadt Germany
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6
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Ponomarev VI, Konovalikhin SV, Kovalev ID, Vershinnikov VI, Borovinskaya IP. Synthesis and crystal structure of [B12]2[CBC][C2]Mg1.42’ a new modification of B25C4Mg1.42. MENDELEEV COMMUNICATIONS 2014. [DOI: 10.1016/j.mencom.2013.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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7
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Synthesis, crystal structure and properties of Mg3B36Si9C and related rare earth compounds RE3−xB36Si9C (RE=Y, Gd–Lu). J SOLID STATE CHEM 2013. [DOI: 10.1016/j.jssc.2013.05.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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8
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Effect of transition element doping on crystal structure of rare earth borosilicides REB44Si2. J SOLID STATE CHEM 2011. [DOI: 10.1016/j.jssc.2011.04.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Vojteer N, Sagawe V, Stauffer J, Schroeder M, Hillebrecht H. LiB
12
PC, the First Boron‐Rich Metal Boride with Phosphorus—Synthesis, Crystal Structure, Hardness, Spectroscopic Investigations. Chemistry 2011; 17:3128-35. [DOI: 10.1002/chem.201002968] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Indexed: 11/05/2022]
Affiliation(s)
- Natascha Vojteer
- Institut für Anorganische und Analytische Chemie, Albertstr. 21, 79104 Freiburg (Germany), Fax: (+49) 761203‐6021
| | - Vanessa Sagawe
- Institut für Anorganische und Analytische Chemie, Albertstr. 21, 79104 Freiburg (Germany), Fax: (+49) 761203‐6021
| | - Julia Stauffer
- Institut für Anorganische und Analytische Chemie, Albertstr. 21, 79104 Freiburg (Germany), Fax: (+49) 761203‐6021
| | - Melanie Schroeder
- Institut für Anorganische und Analytische Chemie, Albertstr. 21, 79104 Freiburg (Germany), Fax: (+49) 761203‐6021
| | - Harald Hillebrecht
- Institut für Anorganische und Analytische Chemie, Albertstr. 21, 79104 Freiburg (Germany), Fax: (+49) 761203‐6021
- Freiburger Materialforschungszentrum FMF, Stefan‐Meier‐Str. 25, 79104 Freiburg (Germany)
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10
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Pediaditakis A, Schroeder M, Sagawe V, Ludwig T, Hillebrecht H. Binary Boron-Rich Borides of Magnesium: Single-Crystal Investigations and Properties of MgB7 and the New Boride Mg∼5B44. Inorg Chem 2010; 49:10882-93. [PMID: 21043472 DOI: 10.1021/ic1012389] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexis Pediaditakis
- Albert-Ludwigs-Universität Freiburg Institut für Anorganische und Analytische Chemie, Albertstrasse 21, D-79104 Freiburg, Germany
| | - Melanie Schroeder
- Albert-Ludwigs-Universität Freiburg Institut für Anorganische und Analytische Chemie, Albertstrasse 21, D-79104 Freiburg, Germany
| | - Vanessa Sagawe
- Albert-Ludwigs-Universität Freiburg Institut für Anorganische und Analytische Chemie, Albertstrasse 21, D-79104 Freiburg, Germany
| | - Thilo Ludwig
- Albert-Ludwigs-Universität Freiburg Institut für Anorganische und Analytische Chemie, Albertstrasse 21, D-79104 Freiburg, Germany
| | - Harald Hillebrecht
- Albert-Ludwigs-Universität Freiburg Institut für Anorganische und Analytische Chemie, Albertstrasse 21, D-79104 Freiburg, Germany
- Freiburger Materialforschungszentrum FMF, Stefan-Maier-Strasse 25, D-79104 Freiburg, Germany
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11
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Single crystal studies on boron-rich τ-borides Ni23−xMxB6 (M=Zn, Ga, In, Sn, Ir)—The surprising occurrence of B4-tetraheda as a normal case? J SOLID STATE CHEM 2010. [DOI: 10.1016/j.jssc.2010.07.048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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Adasch V, Schroeder M, Kotzott D, Ludwig T, Vojteer N, Hillebrecht H. Synthesis, Crystal Structure, and Properties of MgxB50C8 or Mgx(B12)4(CBC)2(C2)2 (x = 2.4−4). J Am Chem Soc 2010; 132:13723-32. [DOI: 10.1021/ja102659d] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Volker Adasch
- DRONCO AG, Wiesenmühle 1, D-95632 Wunsiedel, Germany, Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, and Freiburger Materialforschungszentrum FMF, Stefan-Maier-Strasse 25, D-79104 Freiburg, Germany
| | - Melanie Schroeder
- DRONCO AG, Wiesenmühle 1, D-95632 Wunsiedel, Germany, Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, and Freiburger Materialforschungszentrum FMF, Stefan-Maier-Strasse 25, D-79104 Freiburg, Germany
| | - Dominik Kotzott
- DRONCO AG, Wiesenmühle 1, D-95632 Wunsiedel, Germany, Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, and Freiburger Materialforschungszentrum FMF, Stefan-Maier-Strasse 25, D-79104 Freiburg, Germany
| | - Thilo Ludwig
- DRONCO AG, Wiesenmühle 1, D-95632 Wunsiedel, Germany, Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, and Freiburger Materialforschungszentrum FMF, Stefan-Maier-Strasse 25, D-79104 Freiburg, Germany
| | - Natascha Vojteer
- DRONCO AG, Wiesenmühle 1, D-95632 Wunsiedel, Germany, Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, and Freiburger Materialforschungszentrum FMF, Stefan-Maier-Strasse 25, D-79104 Freiburg, Germany
| | - Harald Hillebrecht
- DRONCO AG, Wiesenmühle 1, D-95632 Wunsiedel, Germany, Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, and Freiburger Materialforschungszentrum FMF, Stefan-Maier-Strasse 25, D-79104 Freiburg, Germany
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13
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Jiang X, Zhao J, Wu A, Bai Y, Jiang X. Mechanical and electronic properties of B12-based ternary crystals of orthorhombic phase. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:315503. [PMID: 21399366 DOI: 10.1088/0953-8984/22/31/315503] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Using first-principles calculations, the structural, mechanical and electronic properties of the experimentally synthesized B(12)-based ternary crystals (AlMgB(14), AlNaB(14), AlLiB(14), Mg(2)B(14), MgSi(2)B(12), MgC(2)B(12), Li(2)Si(2)B(12) and Li(2)C(2)B(12)) have been investigated. The theoretical equilibrium lattice constants of these crystals agree with the experimental values. The Vickers hardness (H(v)) estimated from the theoretical Young's moduli ranges from 20 to 30 GPa, and the MgC(2)B(12) compound (H(v) = 31.4 GPa) is harder than α-boron. Based on the electron density of states and Mulliken population analysis, the origination of hardness and interaction between the interstitial atoms and the B(12) framework were discussed. Scaled bond order of the B-B bonds was used to interpret the hardness of these B(12)-based ternary compounds. The crystal hardness is primarily determined by the B(12) icosahedral skeleton, whereas the contributions of metal atoms manifest as the electron transfer from metal to B atoms. We also calculated the ideal tensile strength of AlMgB(14) and MgC(2)B(12) and found that the <001> and <010> directions are their cleavage directions under tensile strains, respectively.
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Affiliation(s)
- Xue Jiang
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, People's Republic of China
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Morito H, Eck B, Dronskowski R, Yamane H. Synthesis and crystal structure of sodium borosilicide, Na8B74.5Si17.5. Dalton Trans 2010; 39:10197-202. [DOI: 10.1039/c0dt00801j] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Albert B, Hillebrecht H. Bor - elementare Herausforderung für Experimentatoren und Theoretiker. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200903246] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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16
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Albert B, Hillebrecht H. Boron: Elementary Challenge for Experimenters and Theoreticians. Angew Chem Int Ed Engl 2009; 48:8640-68. [DOI: 10.1002/anie.200903246] [Citation(s) in RCA: 440] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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17
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Single crystal studies on Co-containing τ-borides Co23−xMxB6 (M=Al, Ga, Sn, Ti, V, Ir) and the boron-rich τ-boride Co12.3Ir8.9B10.5. J SOLID STATE CHEM 2009. [DOI: 10.1016/j.jssc.2008.10.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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18
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Vojteer N, Schroeder M, Röhr C, Hillebrecht H. Li2B12Si2: The First Ternary Compound in the System Li/B/Si: Synthesis, Crystal Structure, Hardness, Spectroscopic Investigations, and Electronic Structure. Chemistry 2008; 14:7331-42. [DOI: 10.1002/chem.200701949] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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19
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Adasch V, Hess KU, Ludwig T, Vojteer N, Hillebrecht H. Synthesis, crystal structure, and properties of two modifications of MgB(12)C(2). Chemistry 2007; 13:3450-8. [PMID: 17236227 DOI: 10.1002/chem.200601002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Single crystals of two modifications of the new magnesium boride carbide MgB(12)C(2) were synthesized from the elements in a metallic melt by using tantalum ampoules. Crystals were characterized by single-crystal X-ray diffraction and electron microprobe analysis (energy-dispersive (EDX) and wavelength-dispersive (WDX) X-ray spectroscopy). Orthorhombic MgB(12)C(2) is formed in a Cu/Mg melt at 1873 K. The crystal structure of o-MgB(12)C(2) (Imma, Z=4, a=5.6133(10), b=9.828(2), c=7.9329(15) A, 574 reflections, 42 variables, R(1)(F)=0.0208, wR(2)(I)=0.0540) consists of a hexagonal primitive array of B(12) icosahedra with Mg atoms and C(2) units in trigonal-prismatic voids. Each icosahedron has six exohedral B--B and six B--C bonds. Carbon is tetrahedrally coordinated by three boron atoms and one carbon atom with a remarkably long C--C distance of 1.727 A. Monoclinic MgB(12)C(2) is formed in an Al/Mg melt at 1573 K. The structure of m-MgB(12)C(2) (C2/c, Z=4, a=7.2736(11), b=8.7768(13), c=7.2817(11) A, beta=105.33(3) degrees , 1585 reflections, 71 variables, R(1)(F)=0.0228, wR(2)(I)=0.0610) may be described as a distorted cubic close arrangement of B(12) icosahedra. Tetrahedral voids are filled by C atoms and octahedral voids are occupied by Mg atoms. The icosahedra are interconnected by four exohedral B--B bonds to linear chains and by eight interstitial C atoms to form a three-dimensional covalent network. Both compounds fulfill the electron-counting rules of Wade and Longuet-Higgins.
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20
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Breher F. Stretching bonds in main group element compounds—Borderlines between biradicals and closed-shell species. Coord Chem Rev 2007. [DOI: 10.1016/j.ccr.2006.09.007] [Citation(s) in RCA: 271] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Adasch V, Hess KU, Ludwig T, Vojteer N, Hillebrecht H. Synthesis and crystal structure of Mg2B24C, a new boron-rich boride related to “tetragonal boron I”. J SOLID STATE CHEM 2006. [DOI: 10.1016/j.jssc.2006.04.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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