Identifiers | |
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3D model (JSmol) | |
ChemSpider | |
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Properties | |
C7H4FeO3 | |
Molar mass | 191.951 g·mol−1 |
Appearance | pale yellow oil |
Boiling point | 47 °C (117 °F; 320 K) 3 mm |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Cyclobutadieneiron tricarbonyl is an organoiron compound with the formula Fe(C4H4)(CO)3. It is a yellow oil that is soluble in organic solvents. It has been used in organic chemistry as a precursor for cyclobutadiene, which is an elusive species in the free state. [1]
Cyclobutadieneiron tricarbonyl was first prepared in 1965 by Pettit from 3,4-dichlorocyclobutene and diiron nonacarbonyl: [2] [3]
The compound is an example of a piano stool complex. The C-C distances are 1.426 Å. [4]
Oxidative decomplexation of cyclobutadiene is achieved by treating the tricarbonyl complex with ceric ammonium nitrate. The released cyclobutadiene is trapped with a quinone, which functions as a dienophile. [5]
Cyclobutadieneiron tricarbonyl displays aromaticity as evidenced by some of its reactions, which can be classified as electrophilic aromatic substitution: [6]
It undergoes Friedel-Crafts acylation with acetyl chloride and aluminium chloride to give the acyl derivative 2, with formaldehyde and hydrochloric acid to the chloromethyl derivative 3, in a Vilsmeier-Haack reaction with N-methylformanilide and phosphorus oxychloride to the formyl 4, and in a Mannich reaction to amine derivative 5.
The reaction mechanism is identical to that of EAS:
Several years before Petit's work, (C4Ph4)Fe(CO)3 had been prepared from the reaction of iron carbonyl and diphenylacetylene. [7]
(Butadiene)iron tricarbonyl is isoelectronic with cyclobutadieneiron tricarbonyl.
In 1956, Longuet-Higgins and Orgel [8] predicted the existence of transition-metal cyclobutadiene complexes, in which the degenerate eg orbital of cyclobutadiene has the correct symmetry for π interaction with the dxz and dyz orbitals of the proper metal. The compound was synthesized three years after the prediction [9] This is a case of theory before experiment. [10]
Cyclobutadiene is an organic compound with the formula C4H4. It is very reactive owing to its tendency to dimerize. Although the parent compound has not been isolated, some substituted derivatives are robust and a single molecule of cyclobutadiene is quite stable. Since the compound degrades by a bimolecular process, the species can be observed by matrix isolation techniques at temperatures below 35 K. It is thought to adopt a rectangular structure.
Anisole, or methoxybenzene, is an organic compound with the formula CH3OC6H5. It is a colorless liquid with a smell reminiscent of anise seed, and in fact many of its derivatives are found in natural and artificial fragrances. The compound is mainly made synthetically and is a precursor to other synthetic compounds. Structurally, it is an ether with a methyl and phenyl group attached. Anisole is a standard reagent of both practical and pedagogical value.
In chemistry, a chemical trap is a chemical compound that is used to detect unstable compounds. The method relies on efficiency of bimolecular reactions with reagents to produce a more easily characterize trapped product. In some cases, the trapping agent is used in large excess.
1,3,5,7-Cyclooctatetraene (COT) is an unsaturated derivative of cyclooctane, with the formula C8H8. It is also known as [8]annulene. This polyunsaturated hydrocarbon is a colorless to light yellow flammable liquid at room temperature. Because of its stoichiometric relationship to benzene, COT has been the subject of much research and some controversy.
Iron pentacarbonyl, also known as iron carbonyl, is the compound with formula Fe(CO)5. Under standard conditions Fe(CO)5 is a free-flowing, straw-colored liquid with a pungent odour. Older samples appear darker. This compound is a common precursor to diverse iron compounds, including many that are useful in small scale organic synthesis.
Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group [R−N+≡N]X− where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halide. The parent compound where R is hydrogen, is diazenylium.
Diiron nonacarbonyl is an organometallic compound with the formula Fe2(CO)9. This metal carbonyl is an important reagent in organometallic chemistry and of occasional use in organic synthesis. It is a more reactive source of Fe(0) than Fe(CO)5. This micaceous orange solid is virtually insoluble in all common solvents.
Organotitanium chemistry is the science of organotitanium compounds describing their physical properties, synthesis, and reactions. Organotitanium compounds in organometallic chemistry contain carbon-titanium chemical bonds. They are reagents in organic chemistry and are involved in major industrial processes.
Tropone or 2,4,6-cycloheptatrien-1-one is an organic compound with some importance in organic chemistry as a non-benzenoid aromatic. The compound consists of a ring of seven carbon atoms with three conjugated alkene groups and a ketone group. The related compound tropolone (2-hydroxy-2,4,6-cycloheptatrien-1-one) has an additional alcohol group next to the ketone. Tropones are uncommon in natural products, with the notable exception of the 2-hydroxyl derivatives, which are called tropolones.
In organic chemistry, pentadiene is any hydrocarbon with an open chain of five carbons, connected by two single bonds and two double bonds. All those compounds have the same molecular formula C5H8. The inventory of pentadienes include:
Organomanganese chemistry is the chemistry of organometallic compounds containing a carbon to manganese chemical bond. In a 2009 review, Cahiez et al. argued that as manganese is cheap and benign, organomanganese compounds have potential as chemical reagents, although currently they are not widely used as such despite extensive research.
Organoiron chemistry is the chemistry of iron compounds containing a carbon-to-iron chemical bond. Organoiron compounds are relevant in organic synthesis as reagents such as iron pentacarbonyl, diiron nonacarbonyl and disodium tetracarbonylferrate. Although iron is generally less active in many catalytic applications, it is less expensive and "greener" than other metals. Organoiron compounds feature a wide range of ligands that support the Fe-C bond; as with other organometals, these supporting ligands prominently include phosphines, carbon monoxide, and cyclopentadienyl, but hard ligands such as amines are employed as well.
Organosodium chemistry is the chemistry of organometallic compounds containing a carbon to sodium chemical bond. The application of organosodium compounds in chemistry is limited in part due to competition from organolithium compounds, which are commercially available and exhibit more convenient reactivity.
Organomolybdenum chemistry is the chemistry of chemical compounds with Mo-C bonds. The heavier group 6 elements molybdenum and tungsten form organometallic compounds similar to those in organochromium chemistry but higher oxidation states tend to be more common.
Rowland Pettit was an Australian-born American chemist. He was awarded an overseas scholarship from the Royal Commission 1851 from 1952 - 1954. He came to London to Queen Mary College to conduct research into "the molecular orbital theory of organic chemistry and its application". Pettit was noted for preparation of Cyclobutadieneiron tricarbonyl and the related trimethylenemethane complex. Pettit was head of the Department of Chemistry and W. T. Doherty Professor in Chemistry at the University of Texas, Austin, a member of the National Academy of Sciences, a member of the American Chemical Society, a member of the Chemical Society of London, a recipient of the American Chemical Society's the Southwest Regional Award, a member of the American Academy of Arts and Sciences.
Half sandwich compounds, also known as piano stool complexes, are organometallic complexes that feature a cyclic polyhapto ligand bound to an MLn center, where L is a unidentate ligand. Thousands of such complexes are known. Well-known examples include cyclobutadieneiron tricarbonyl and (C5H5)TiCl3. Commercially useful examples include (C5H5)Co(CO)2, which is used in the synthesis of substituted pyridines, and methylcyclopentadienyl manganese tricarbonyl, an antiknock agent in petrol.
(Butadiene)iron tricarbonyl is an organoiron compound with the formula (C4H6)Fe(CO)3. It is a well-studied metal complex of butadiene. An orange-colored viscous liquid that freezes just below room temperature, the compound adopts a piano stool structure.
In chemistry, decomplexation refers to the removal of a ligand from a coordination complex. Decomplexation is of particular interest when the ligand has been synthesized within the coordination sphere of the metal, as is often the case in organometallic chemistry.
Trimethylenemethane complexes are metal complexes of the organic compound trimethylenemethane. Several examples are known, and some have been employed in organic synthesis.
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.