Diiron nonacarbonyl

Structural formula
General
Surname	Diiron nonacarbonyl
other names	Tris (µ-carbonyl) hexacarbonyl diiron [(CO) 3 Fe (μ-CO) 3 Fe (CO) 3 ] Diiron nonacarbonyl Diiron neacarbonyl Iron neacarbonyl
Molecular formula	[Fe 2 (CO) 9 ]
Brief description	yellow-orange crystals
External identifiers / databases
CAS number 15321-51-4 EC number 239-359-5 ECHA InfoCard 100.035.765 PubChem 6096993 ChemSpider 26496632 Wikidata Q416194
properties
Molar mass	363.78 g mol −1
Physical state	firmly
density	2.85 g cm −3
Melting point	100 ° C (decomposition)
solubility	almost insoluble in water
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 228-301-331 P: 210-261-301 + 310-311
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Diiron nonacarbonyl (named after IUPAC : Tris (μ-carbonyl) hexacarbonyldiisen (0) ) is one of the three carbonyls of iron . In organometallic chemistry, the compound is used as a reactive to transfer a [Fe (CO) ₃ ] group, which is isolobal to a BH (or B) or a C fragment (structure of cluster compounds ).

Occurrence

Dieisennonacarbonyl arises z. B. in iron extraction in a blast furnace:

${\displaystyle {\ce {2Fe + 9CO -> [Fe2(CO)9]}}}$

presentation

[Fe ₂ (CO) ₉ ] is represented by irradiating liquid iron pentacarbonyl with UV light .

${\displaystyle {\ce {2[Fe(CO)5] -> [Fe2(CO)9] + CO ^}}}$

properties

Diiron nonacarbonyl on a fritted glass filter

Diiron nonacarbonyl is in the form of shiny, golden-yellow flakes which are fairly stable in dry air and which can be kept undecomposed at -35 ° C in an inert gas atmosphere. It is insoluble in aliphatic hydrocarbons, benzene and diethyl ether and very slightly soluble in methanol . Slow decomposition occurs when exposed to tetrahydrofuran and chlorinated hydrocarbons. In the presence of organic solvents, decomposition takes place from about 60 ° C with formation of iron pentacarbonyl and triiron dodecacarbonyl without the release of carbon monoxide. In the solid state, decomposition occurs between 100 and 120 ° C after:

${\displaystyle {\ce {3[Fe2(CO)9] -> 3[Fe(CO)5] + [Fe3(CO)12]}}}$

${\displaystyle {\ce {[Fe3(CO)12] -> 3Fe + 12CO ^}}}$

Diiron nonacarbonyl consists of two iron atoms 246 pm apart, to each of which three terminal carbonyl ligands are bound. Three other carbonyl groups are bridging between the iron atoms. Whether there is a direct metal-to-metal bond between the iron atoms is difficult to answer and is controversial, since none of the possible criteria for metal-to-metal bonds such as bond lengths , magnetism and the 18-electron rule allow a final statement. Theoretical calculations suggest, however, that there is no direct iron-iron bond and that the bond in the molecule is solely due to interactions via the CO bridge.

Further iron carbonyls

• Iron pentacarbonyl [Fe (CO) ₅ ]
• Triiron dodecacarbonyl [Fe ₃ (CO) ₁₂ ]

Individual evidence

1. ↑ ^{a b c d} Datasheet Nonacarbonyldiiron at AlfaAesar, accessed on February 25, 2010 ( PDF )(JavaScript required) .
2. ↑ ^{a b} Datasheet diironnonacarbonyl from Sigma-Aldrich , accessed on March 24, 2011 ( PDF ).
3. ↑ ^{a b} Georg Brauer (Ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 , p. 1828.
4. ↑ Christoph Elschenbroich: Organometallchemie . 6th edition, Teubner Wiesbaden, 2008, ISBN 978-3-8351-0167-8 , p. 332.
5. ↑ Christoph Elschenbroich: Organometallchemie . 6th edition, Teubner Wiesbaden, 2008, ISBN 978-3-8351-0167-8 , pp. 334-335.
6. ↑ Yaoming Xie, Henry F. Schaefer III, R. Bruce King: Binuclear Homoleptic Iron Carbonyls: Incorporation of Formal Iron − Iron Single, Double, Triple, and Quadruple Bonds, Fe ₂ (CO) _x (x = 9, 8, 7 , 6). In: J. Am. Chem. Soc. 2000, 122, 36, pp. 8746-8761 ( doi : 10.1021 / ja001162y ).

Web links

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