Zirconium (IV) borohydride
Structural formula | |||||||
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General | |||||||
Surname | Zirconium (IV) borohydride | ||||||
other names |
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Molecular formula | Zr (BH 4 ) 4 | ||||||
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properties | |||||||
Molar mass | 150.59 g mol −1 | ||||||
Physical state |
solid to liquid |
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Melting point |
28.7 ° C |
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boiling point |
123 ° C |
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Zirconium (IV) borohydride is a chemical compound from the group of zirconium compounds and boranes .
Extraction and presentation
The synthesis takes place through the reaction of lithium borohydride with zirconium (IV) chloride .
properties
Zirconium (IV) borohydride is a low-melting solid and a volatile liquid above its melting point. The low melting point at 28.7 ° C and the low boiling point at 123 ° C indicate a complex compound instead of an ionic salt compound. The determination of the crystal structure revealed a highly coordinated structure, three of the hydrogen atoms of the boronate units being coordinated with the central ion. The thermal decomposition of the compound above 250 ° C. gives a product with the composition ZrB 2.76-3.74 , the crystalline phase consisting of zirconium diboride and the remainder of amorphous boron . In the gas phase, the decomposition takes place according to:
The compound is pyrophoric , it self-ignites in the presence of air, whereby the ignition can be delayed with an explosion. Rapid hydrolysis occurs in the presence of water.
use
The compound serves as a starting material for the production of zirconium diboride ZrB 2 , which can be used for high-temperature ceramics or for coating glass or metal surfaces. It is used as an effective reducing agent in organic chemistry. The compound has also been proposed as a hydrogen storage material.
Web links
Individual evidence
- ↑ a b c d e f Roth / Weller: Hazardous chemical reactions , ecomed SECURITY, Hüthig Jehle Rehm publishing group, edition 08/2011.
- ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
- ↑ a b Rice, GW; Woodin, RL: Zirconium Borohydride as a Zirconium Boride Precursor in J. Am. Ceramic Soc. 71 (1988) c181-c183, doi : 10.1111 / j.1151-2916.1988.tb05867.x .
- ↑ Bird, PH; Churchill, MR: The crystal structure of zirconium (IV) borohydride (at -160 °) in Chem. Commun. (London), 1967, 403, doi : 10.1039 / C19670000403 .
- ↑ Andrievskii, RA; Kravchenko, SE; Shilkin, SP: Preparation and some properties of ultrafine zirconium boride and titanium boride powders in Inorganic Materials (Translation of Neorganicheskie Materialy) 31 (1995) 965-968.
- ↑ a b Jensen, J A .; Gozum, JE; Pollina, DM; Girolami, GS: Titanium, zirconium, and hafnium tetrahydroborates as "tailored" CVD precursors for metal diboride thin films in J. Am. Chem. Soc. 110 (1988) 1643-1644, doi : 10.1021 / ja00213a058 .
- ↑ Narasimhan, S .; Balakumar, R .: Zirconium Borohydride - a Versatile Reducing Agent for the Reduction of Electrophilic and Nucleophilic Substrates in Synth. Comm. 30 (2000) 4387-4395, doi : 10.1080 / 00397910008087061 .
- ↑ Soloveichik, GL: Metal Borohydrides as Hydrogen Storage Materials in Material Matters 2007, 2.2, 11.