Potassium zinc borohydrides containing triangular [Zn(BH4)3]-- and tetrahedral [Zn(BH4)xCl4-x]2-- anions
| hal.structure.identifier | Laboratory of Crystallography | |
| dc.contributor.author | ČERNÝ, Radovan | |
| hal.structure.identifier | Center for Materials Crystallography (CMC), Interdisciplinary Nanoscience Center (iNANO) | |
| dc.contributor.author | RAVNSBÆK, Dorthe B. | |
| hal.structure.identifier | Laboratory of Crystallography | |
| dc.contributor.author | SCHOUWINK, Pascal | |
| hal.structure.identifier | Institut de la matière condensée et des nanosciences / Institute of Condensed Matter and Nanosciences [IMCN] | |
| dc.contributor.author | FILINCHUK, Yaroslav | |
| hal.structure.identifier | Laboratory of Crystallography | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | PENIN, Nicolas | |
| hal.structure.identifier | Department of Solid State Physics | |
| dc.contributor.author | TEYSSIER, Jeremie | |
| hal.structure.identifier | Institute of Inorganic Chemistry | |
| dc.contributor.author | SMRČO, L'Ubomír | |
| hal.structure.identifier | Center for Materials Crystallography (CMC), Interdisciplinary Nanoscience Center (iNANO) | |
| dc.contributor.author | JENSEN, Torben R. | |
| dc.date.issued | 2012 | |
| dc.identifier.issn | 1932-7447 | |
| dc.description.abstractEn | Three novel potassium-zinc borohydrides/chlorides are described. KZn(BH<sub>4</sub>)<sub>3</sub> and K<sub>2</sub>Zn(BH<sub>4</sub>)<sub><i>x</i></sub>Cl<sub>4-<i>x</i></sub> form in ball-milled KBH<sub>4</sub>:ZnCl<sub>2</sub> mixtures with molar ratios ranging from 1.5:1 up to 3:1. On the other hand, K<sub>3</sub>Zn(BH<sub>4</sub>)<sub><i>x</i></sub>Cl<sub>5-<i>x</i></sub> forms only in the 2:1 mixture after longer milling times. The new compounds have been studied by a combination of in situ synchrotron powder diffraction, thermal analysis, Raman spectroscopy, and the solid state DFT calculations. Rhombohedral KZn(BH<sub>4</sub>)<sub>3</sub> contains an anionic complex [Zn(BH<sub>4</sub>)<sub>3</sub>]<sup>−</sup> with <i>D</i><sub>3</sub> (32) symmetry, located inside a rhombohedron K<sub>8</sub>. KZn(BH<sub>4</sub>)<sub>3</sub> contains 8.1 wt % of hydrogen and decomposes at 385 K with a release of hydrogen and diborane similar to other Zn-based bimetallic borohydrides like MZn<sub>2</sub>(BH<sub>4</sub>)<sub>5</sub> (M = Li, Na) and NaZn(BH<sub>4</sub>)<sub>3</sub>. The decomposition temperature is much lower than for KBH<sub>4</sub>. Monoclinic K<sub>2</sub>Zn(BH<sub>4</sub>)<sub><i>x</i></sub>Cl<sub>4-<i>x</i></sub> contains a tetrahedral complex anion [Zn(BH<sub>4</sub>)<sub><i>x</i></sub>Cl<sub>4-<i>x</i></sub>]<sup>2</sup><sup>-</sup> located inside an Edshammar polyhedron (pentacapped trigonal prism) K<sub>11</sub>. The compound is a monoclinically distorted variant of the paraelectric orthorhombic <i>ht</i>-phase of K<sub>2</sub>ZnCl<sub>4</sub> (structure type K<sub>2</sub>SO<sub>4</sub>). K<sub>2</sub>Zn(BH<sub>4</sub>)<sub><i>x</i></sub>Cl<sub>4-<i>x</i></sub> releases BH<sub>4</sub> starting from 395 K, forming Zn and KBH<sub>4</sub>. As the reaction proceeds and <i>x</i> decreases, the monoclinic distortion of K<sub>2</sub>Zn(BH<sub>4</sub>)<sub><i>x</i></sub>Cl<sub>4-<i>x</i></sub> diminishes and the structure transforms at 445 K into the orthorhombic <i>ht</i>-phase of K<sub>2</sub>ZnCl<sub>4</sub>. Tetragonal K<sub>3</sub>Zn(BH<sub>4</sub>)<sub><i>x</i></sub>Cl<sub>5-<i>x</i></sub> is a substitutional and deformation variant of the tetragonal (<i>I</i>4/<i>mcm</i>) Cs<sub>3</sub>CoCl<sub>5</sub> structure type possibly with the space group <i>P</i>4<sub>2</sub>/<i>ncm</i>. K<sub>3</sub>Zn(BH<sub>4</sub>)<sub><i>x</i></sub>Cl<sub>5-<i>x</i></sub> decomposes nearly at the same temperature as KZn(BH<sub>4</sub>)<sub>3</sub>, i.e., at 400 K, with the formation of K<sub>2</sub>Zn(BH<sub>4</sub>)<sub><i>x</i></sub>Cl<sub>4-<i>x</i></sub> and KBH<sub>4</sub>, indicating that the compound is an adduct of the two latter compounds. | |
| dc.language.iso | en | |
| dc.publisher | American Chemical Society | |
| dc.subject.en | Inorganic compounds | |
| dc.subject.en | Raman spectroscopy | |
| dc.subject.en | Synchrotron powder diffraction | |
| dc.subject.en | Thermal analysis | |
| dc.subject.en | Solid state DFT calculations | |
| dc.subject.en | Crystal structure | |
| dc.subject.en | Potassium zinc borohydrides | |
| dc.title.en | Potassium zinc borohydrides containing triangular [Zn(BH4)3]-- and tetrahedral [Zn(BH4)xCl4-x]2-- anions | |
| dc.type | Article de revue | |
| dc.identifier.doi | 10.1021/jp209848r | |
| dc.subject.hal | Chimie/Matériaux | |
| bordeaux.journal | Journal of Physical Chemistry C | |
| bordeaux.page | 1563-1571 | |
| bordeaux.volume | 116 | |
| bordeaux.issue | 1 | |
| bordeaux.peerReviewed | oui | |
| hal.identifier | hal-00675284 | |
| hal.version | 1 | |
| hal.popular | non | |
| hal.audience | Internationale | |
| hal.origin.link | https://hal.archives-ouvertes.fr//hal-00675284v1 | |
| bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Journal%20of%20Physical%20Chemistry%20C&rft.date=2012&rft.volume=116&rft.issue=1&rft.spage=1563-1571&rft.epage=1563-1571&rft.eissn=1932-7447&rft.issn=1932-7447&rft.au=%C4%8CERN%C3%9D,%20Radovan&RAVNSB%C3%86K,%20Dorthe%20B.&SCHOUWINK,%20Pascal&FILINCHUK,%20Yaroslav&PENIN,%20Nicolas&rft.genre=article |
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