Hafnium (IV) chloride
Crystal structure | |||||||||||||||||||
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__ Hf 4+ __ Cl - | |||||||||||||||||||
General | |||||||||||||||||||
Surname | Hafnium (IV) chloride | ||||||||||||||||||
other names |
Hafnium tetrachloride |
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Ratio formula | HfCl 4 | ||||||||||||||||||
Brief description |
white solid |
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External identifiers / databases | |||||||||||||||||||
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properties | |||||||||||||||||||
Molar mass | 320.30 g mol −1 | ||||||||||||||||||
Physical state |
firmly |
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Melting point |
432 ° C (enclosed under own pressure) |
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Sublimation point |
315 ° C |
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Vapor pressure |
1 hPa (190 ° C) |
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solubility |
reacts with water |
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safety instructions | |||||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Hafnium (IV) chloride is an inorganic chemical compound of hafnium from the group of chlorides .
Extraction and presentation
Hafnium (IV) chloride can be obtained by chlorinating hafnium with chlorine at 320 ° C.
Hafnium (II) hydride can also be obtained by reacting with hydrogen chloride .
Another possibility is the representation by reacting the oxide with gaseous carbon tetrachloride (in a nitrogen stream) at 450 ° C to 500 ° C:
properties
Hafnium (IV) chloride is a hygroscopic, white crystalline powder that forms hydrochloric acid mist in moist air and is vigorously decomposed by water, producing hafnium oxychloride .
It sublimes at 315 ° C and melts under pressure at 432 ° C. The crystal structure of the compound is monoclinic with the space group P 2 / c (space group no. 13) and is composed of slightly distorted HfCl 6 - octahedra which extended cis-linked HfCl 2 Cl 4/2 form chains.
use
Hafnium (IV) chloride is used as the starting compound for the chemical vapor deposition of hafnium carbide .
Individual evidence
- ↑ a b c d Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1358.
- ↑ a b c d e data sheet Hafnium (IV) chloride, purified by sublimation, 99.9% trace metals basis from Sigma-Aldrich , accessed on May 3, 2013 ( PDF ).
- ↑ a b c W. S. Hummers et al .: Zirconium and hafnium tetrachlorides . In: JC Bailar, Jr. (Ed.): Inorganic Syntheses . tape 4 . McGraw-Hill, Inc., 1953, pp. 121-126 (English).
- ^ A b Mark D. Allendorf: Proceedings of the Symposium on Fundamental Gas Phase and Surface Chemistry ... The Electrochemical Society, 1999, ISBN 1-56677-217-6 , pp. 265 ( limited preview in Google Book search).
- ↑ R. Niewa and H. Jacobs (1995). Crystal structure of hafnium (IV) chloride, HfCl 4 . Journal of Crystallography - Crystalline Materials: Vol. 210, No. 9, pp. 687-687. doi : 10.1524 / zkri.1995.210.9.687