Ytterbium (II) iodide
Crystal structure | ||||||||||||||||
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__ Yb 2+ __ I - | ||||||||||||||||
Crystal system | ||||||||||||||||
Space group |
P 3 m 1 (No. 164) |
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Lattice parameters |
a = 448 pm |
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General | ||||||||||||||||
Surname | Ytterbium (II) iodide | |||||||||||||||
other names |
Ytterbium diiodide |
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Ratio formula | YbI 2 | |||||||||||||||
Brief description |
yellow solid |
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External identifiers / databases | ||||||||||||||||
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properties | ||||||||||||||||
Molar mass | 426.85 g mol −1 | |||||||||||||||
Physical state |
firmly |
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Melting point |
780 ° C (decomposition) |
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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 . |
Ytterbium (II) iodide (YbI 2 ) is a chemical compound made up of the elements ytterbium and iodine . It is a yellow solid and also dissolves in water with a yellow color. Ytterbium (II) iodide was introduced together with samarium (II) iodide (SmI 2 ) as a reagent for organic synthesis.
presentation
Ytterbium (II) iodide is produced by thermal degradation of ytterbium (III) iodide :
The representation via ytterbium metal and 1,2-diiodoethane in tetrahydrofuran (THF) has established itself . The reaction takes place at room temperature, however, due to the sensitivity of the reagents, it must be carried out anhydrous and under inert gas. Otherwise rapid oxidation to ytterbium (III) takes place in the presence of oxygen . This can be seen from the change in color from green to yellow solution.
properties
Ytterbium (II) iodide is a yellow solid that dissolves in water, which is also yellow in color. Ytterbium (II) iodide is very sensitive to air and moisture; it is rapidly oxidized to ytterbium (III) in air . The aqueous solution decomposes rapidly with evolution of hydrogen and extensive discoloration; basic iodides are deposited in the process. The reaction is stormy with acids.
YbI 2 sinters at 0.01 Torr from about 780 ° C and yields a viscous melt at about 920 ° C. It starts to disproportionate in Yb and YbI 3 . At about 800 ° C a yellow sublimate of YbI 2 can be observed on the glass walls; this partially hides the disproportionation. The melting point can therefore only be determined imprecisely.
use
Ytterbium (II) iodide is used in addition to samarium (II) iodide (SmI 2 ) as a reagent for numerous organic syntheses.
Individual evidence
- ↑ W. Döll, W. Klemm: Measurements on two and four-valued compounds of rare earths. VI. About the structure of some dihalides , in: Journal for inorganic and general chemistry , 1939 , 241 , pp. 239-258; doi : 10.1002 / zaac.19392410211 .
- ↑ a b c d e G. Jantsch, N. Skalla, H. Jawurek: On the knowledge of the halides of the rare earths. V. - About the halides of ytterbium , in: Journal for inorganic and general chemistry , 1931 , 201 , pp. 207-220; doi : 10.1002 / zaac.19312010119 .
- ↑ a b Data sheet Ytterbium (II) iodide, powder, ≥99.9% trace metals basis from Sigma-Aldrich , accessed on April 25, 2011 ( PDF ).
- ^ A b P. Girard, Jean-Louis Namy, Henri B. Kagan : Divalent Lanthanide Derivatives in Organic Synthesis. 1. Mild Preparation of SmI 2 and YbI 2 and Their Use as Reducing or Coupling Agents , in: J. Am. Chem. Soc. , 1980 , 102 (8), pp. 2693-2698; doi : 10.1021 / ja00528a029 .
- ↑ Gmelin's Handbook of Inorganic Chemistry , System No. 39, Volume C 6, pp. 199-200.
literature
- Henri B. Kagan , Jean-Louis Namy: Lanthanides in organic synthesis , in: Tetrahedron , 1986 , 42 (24), pp. 6573-6614; doi : 10.1016 / S0040-4020 (01) 82098-6 .
- Patrick G. Steel: Recent developments in lanthanide mediated organic synthesis , in: J. Chem. Soc., Perkin Trans. 1 , 2001 , pp. 2727-2751; doi : 10.1039 / a908189e .