Chemistry:(Diene)iron tricarbonyl
In organometallic chemistry, (diene)iron tricarbonyl describes a diverse family of related coordination complexes consisting of a diene ligand coordinated to a Fe(CO)3 center. Often the diene is conjugated, e.g., butadiene, but the family includes nonconjugated dienes as well. The compounds are yellow, air-stable, often low-melting, and soluble in hydrocarbon solvents. The motif is so robust that even unstable dienes form easily characterized derivatives, such as norbornadienone and cyclobutadiene.
Scope
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The inventory of complexes is large, and has been extended to steroidal and terpenoid substrates.
| diene | CAS RN | notes |
|---|---|---|
| (cyclobutadiene)Fe(CO)3 | 12078-17-0 | organge solid, b.p. 47 °C (3 mm)[2] |
| (butadiene)Fe(CO)3 | 12078-32-9 | yellow-orange, m.p. 19 °C |
| (Isoprene)Fe(CO)3 | 32731-93-4 | yellow liquid at RT, chiral[3] |
| (1,3-Cyclohexadiene)Fe(CO)3 | 12252-72-6 | yellow, m.p. 8-9 °C[4] |
| (norbornadiene)Fe(CO)3 | 12307-07-2 | yellow, m.p. -2 °C[5] |
| (norbornadienone)Fe(CO)3 | 12307-01-6 | yellow, m.p. 93-95 °C[6] |
| (1,5-Cyclooctadiene)Fe(CO)3 | 12093-20-8 | yellow, m.p. 76 °C[7][8] |
| (1,3-Cyclooctadiene)Fe(CO)3 | 33270-50-7 | yellow, m.p. 36 °C[7][9] |
Preparation and uses
Many of diene complexes were originally prepared by reaction of iron pentacarbonyl with the diene under UV-radiation. Often yields are modest because the complexes, which are often liquids, volatilize during workup.[5] Some derivatives derivatives are prepared displacement of bda from (benzylideneacetone)iron tricarbonyl (Fe(bda)(CO)
3)[10]
The Fe(CO)3 unit serves as a protecting group for the diene, preventing the diene from participating in Diels-Alder reactions and hydrogenation. The diene is usually deprotected with ceric ammonium nitrate.[11]
These complexes are mainly of academic interest. Some iron tricarbon complexes of cyclopentadienones catalyze hydrogenation, see Knolker complex.
Characterization
thumb|Sample of (butadiene)Fe(CO)3, illustrating the color typical of this family of compounds.|220 px|left IR spectra of these complexes show νCO bands near 2040 and 1969 cm-1. At low temperatures, the lower energy band splits, which has been interpreted as evidence for fluxionality on the IR timescale.[12]
References
- ↑ Mason, R.; Robertson, G. B. (1970). "Crystal and molecular structure of (Vitamin-A aldehyde)tricarbonyliron". Journal of the Chemical Society A: Inorganic, Physical, Theoretical: 1229. doi:10.1039/J19700001229.
- ↑ Pettit, R.; Henery, J. (1970). "Cyclobutadieneiron Tricarbonyl". Organic Syntheses 50: 21. doi:10.15227/orgsyn.050.0021.
- ↑ King, R. B.; Manuel, T. A.; Stone, F. G. A. (1961). "Chemistry of the Metal Carbonyls—IX. Diene Complexes of Iron". Journal of Inorganic and Nuclear Chemistry 16 (3–4): 233–239. doi:10.1016/0022-1902(61)80495-8.
- ↑ Pearson, Anthony J.; Sun, Huikai (2008). "Cyclohexadieneiron Tricarbonyl". e-EROS Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn00791. ISBN 978-0471936237.
- ↑ 5.0 5.1 Green, M. L. H.; Pratt, L.; Wilkinson, G. (1960). "206. Spectroscopic Studies of Some Organoiron Complexes". Journal of the Chemical Society (Resumed): 989. doi:10.1039/JR9600000989.
- ↑ Landesberg, Joseph M.; Sieczkowski, J. (1971). "Synthesis and Chemistry of Tricarbonyl(7-norbornadienone)iron". Journal of the American Chemical Society 93 (4): 972–980. doi:10.1021/ja00733a032.
- ↑ 7.0 7.1 Deeming, A. J.; Ullah, S. S.; Domingos, A. J. P.; Johnson, B. F. G.; Lewis, J. (1974). "Reactivity of co-ordinated ligands. Part XX. Preparation and Reactions of Cyclo-octadiene Complexes of Iron, Ruthenium, and Osmium". Journal of the Chemical Society, Dalton Transactions (19): 2093. doi:10.1039/DT9740002093.
- ↑ Kruczynski, Leonard.; Takats, Josef. (1976). "Intramolecular Rearrangement in (.eta.-diene)tricarbonyliron and -Ruthenium Compounds. A Carbon-13 Nuclear Magnetic Resonance Study". Inorganic Chemistry 15 (12): 3140–3147. doi:10.1021/ic50166a041.
- ↑ Lewis, J.; Cotton, F. A.; Deeming, A. J.; Josty, P. L.; Ullah, S. S.; Domingos, A. J. P.; Johnson, B. F. G. (1971). "Tricarbonyl(cyclooctadiene) Complexes of Iron(0), Ruthenium(0), and Osmium(0)". Journal of the American Chemical Society 93 (18): 4624–4626. doi:10.1021/ja00747a066.
- ↑ Domingos, A. J. P.; Howell, J. A. S.; Johnson, B. F. G.; Lewis, J. (1990). Reagents for the Synthesis of η-Diene Complexes of Tricarbonnyliron and Tricarbonylruthenium. Inorganic Syntheses. pp. 52–55. doi:10.1002/9780470132593.ch11. ISBN 9780470132593.
- ↑ Donaldson, William A.; Chaudhury, Subhabrata (2009). "Recent Applications of Acyclic (Diene)iron Complexes and (Dienyl)iron Cations in Organic Synthesis". European Journal of Organic Chemistry 2009 (23): 3831–3843. doi:10.1002/ejoc.200900141. PMID 21709767.
- ↑ Turner, James J.; Bühl, Michael (2018). "Infrared Dynamics of Iron Carbonyl Diene Complexes". The Journal of Physical Chemistry A 122 (14): 3497–3505. doi:10.1021/acs.jpca.7b12309. PMID 29394061. Bibcode: 2018JPCA..122.3497T.
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