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Cyclobutadieneiron Tricarbonyl
Cyclobutadieneiron tricarbonyl is an organoiron compound with the formula Fe(C4H4)(CO)3. It is a yellow solid 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. Preparation and structure It was first prepared in 1965 by Pettit from 3,4-dichlorocyclobutene and diiron nonacarbonyl: :C4H4Cl2 + 2 Fe2(CO)9 → (C4H4)Fe(CO)3 + 2 Fe(CO)5 + 5 CO + FeCl2 The compound is an example of a piano stool complex. The C-C distances are 1.426 Å. Properties 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. Cyclobutadieneiron tricarbonyl displays aromaticity as evidenced by some of its reactions, which can be classified as electrophilic aromatic substitution: : It undergoes Friedel-Crafts acylation with acetyl chloride and alu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organoiron Compound
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. While iron adopts oxidation states from Fe(−II) through to Fe(VII), Fe(IV) is the highest established oxidation state for organoiron species. Although iron is generally less active in many catalytic applications, it is less expensive and "Green chemistry, 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 HSAB theory, hard ligands such as amines are employed as well. Iron(0) and more reduced states Carbonyl complexes Important metal carbonyls, iron carbonyls are the three neutral binary carbonyls, iron pentacarbonyl, diiron nonacarbonyl, and triiron d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrochloric Acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid Acid strength is the tendency of an acid, symbolised by the chemical formula HA, to dissociate into a proton, H+, and an anion, A-. The dissociation of a strong acid in solution is effectively complete, except in its most concentrated solutions .... It is a component of the gastric acid in the digestive systems of most animal species, including humans. Hydrochloric acid is an important laboratory reagent and industrial chemical. History In the early tenth century, the Persian physician and alchemist Abu Bakr al-Razi ( 865–925, Latin: Rhazes) conducted experiments with sal ammoniac (ammonium chloride) and vitriol (hydrated sulfates of various metals), which he distilled together, thus producing the gas hydrogen chloride. In doing so, al-Razi may have stumbled upon a primitive method ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half Sandwich Compounds
One half ( : halves) is the irreducible fraction resulting from dividing one by two or the fraction resulting from dividing any number by its double. Multiplication by one half is equivalent to division by two, or "halving"; conversely, division by one half is equivalent to multiplication by two, or "doubling". One half often appears in mathematical equations, recipes, measurements, etc. Half can also be said to be one part of something divided into two equal parts. For instance, the area ''S'' of a triangle is computed. :''S'' = × perpendicular height. One half also figures in the formula for calculating figurate numbers, such as triangular numbers and pentagonal numbers: : \frac and in the formula for computing magic constants for magic squares : M_2(n) = \frac \left(n^ + 1\right) The Riemann hypothesis states that every nontrivial complex root of the Riemann zeta function has a real part equal to . One half has two different decimal expansion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organoiron Compounds
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. While iron adopts oxidation states from Fe(−II) through to Fe(VII), Fe(IV) is the highest established oxidation state for organoiron species. 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. Iron(0) and more reduced states Carbonyl complexes Important iron carbonyls are the three neutral binary carbonyls, iron pentacarbonyl, diiron nonacarbonyl, and triiron dodecacarbonyl. One or more carbonyl ligands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonyl Complexes
In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a carbonyl group is often referred to as a carbonyl compound. The term carbonyl can also refer to carbon monoxide as a ligand in an inorganic or organometallic complex (a metal carbonyl, e.g. nickel carbonyl). The remainder of this article concerns itself with the organic chemistry definition of carbonyl, where carbon and oxygen share a double bond. Carbonyl compounds In organic chemistry, a carbonyl group characterizes the following types of compounds: Other organic carbonyls are urea and the carbamates, the derivatives of acyl chlorides chloroformates and phosgene, carbonate esters, thioesters, lactones, lactams, hydroxamates, and isocyanates. Examples of inorganic carbonyl compounds are carbon dioxide and carbonyl sulfide. A sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(Butadiene)iron Tricarbonyl
(Butadiene)iron tricarbonyl is an organoiron compound with the formula (CH)Fe(CO). 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. The complex was first prepared by heating iron pentacarbonyl with the diene. Related compounds Iron(0) complexes of conjugated dienes have been extensively studied. In the butadiene series, (η-CH)Fe(CO) and (η:η-CH)(Fe(CO)) have been crystallized. Many related complexes are known for substituted butadienes and related species. The species (η- isoprene)iron tricarbonyl is chiral. See also * Cyclobutadieneiron tricarbonyl Cyclobutadieneiron tricarbonyl is an organoiron compound with the formula Fe(C4H4)(CO)3. It is a yellow solid that is soluble in organic solvents. It has been used in organic chemistry as a precursor for cyclobutadiene, which is an elusive specie ... References {{DEFAULTSORT:Butadieneirontricarbonyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphenylacetylene
Diphenylacetylene is the chemical compound C6H5C≡CC6H5. The molecule consists of two phenyl groups attached to a C2 unit. A colorless solid, it is used as a building block in organic synthesis and as a ligand in organometallic chemistry. Preparation and structure In one preparation for this compound, benzil is condensed with hydrazine to give the bis(hydrazone), which is oxidized with mercury(II) oxide. Alternatively stilbene is brominated, and the resulting dibromodiphenylethane is subjected to dehydrohalogenation, Yet another method starts involves the coupling iodobenzene and the copper salt of phenylacetylene in the Castro-Stephens coupling. Diphenylacetylene is a planar molecule. The central C≡C distance is 119.8 picometers. Derivatives Reaction of diphenylacetylene with tetraphenylcyclopentadienone results in the formation of hexaphenylbenzene in a Diels–Alder reaction. Reaction of Ph2C2 with benzal chloride in the presence of potassium ''t''-butoxide affords t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Carbonyl
Iron pentacarbonyl, also known as iron carbonyl, is the compound with formula . 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. Properties Iron pentacarbonyl is a homoleptic metal carbonyl, where carbon monoxide is the only ligand complexed with a metal. Other examples include octahedral Cr(CO)6 and tetrahedral Ni(CO)4. Most metal carbonyls have 18 valence electrons, and Fe(CO)5 fits this pattern with 8 valence electrons on Fe and five pairs of electrons provided by the CO ligands. Reflecting its symmetrical structure and charge neutrality, Fe(CO)5 is volatile; it is one of the most frequently encountered liquid metal complexes. Fe(CO)5 adopts a trigonal bipyramidal structure with the Fe atom surrounded by five CO ligands: three in equatorial positions and two axially b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Mechanism
In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs. A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction. The detailed steps of a reaction are not observable in most cases. The conjectured mechanism is chosen because it is thermodynamically feasible, and has experimental support in isolated intermediates (see next section) or other quantitative and qualitative characteristics of the reaction. It also describes each reactive intermediate, activated complex, and transition state, and which bonds are broken (and in what order), and which bonds are formed (and in what order). A complete mechanism must also explain the reason for the reactants and catalyst used, the stereochemistry observed in reactants and products, all products formed and the amount of each. The electron or arrow pushing method is often used in i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannich Reaction
In organic chemistry, the Mannich reaction is a three-component organic reaction that involves the amino alkylation of an acidic proton next to a carbonyl () functional group by formaldehyde () and a primary or secondary amine () or ammonia (). The final product is a β-amino-carbonyl compound also known as a Mannich base. Reactions between aldimines and α-methylene carbonyls are also considered Mannich reactions because these imines form between amines and aldehydes. The reaction is named after Carl Mannich. center, 500px, Scheme 1 - Ammonia or an amine reacts with formaldehyde and an alpha acidic proton of a carbonyl compound to a beta amino carbonyl compound. The Mannich reaction starts with the nucleophilic addition of an amine to a carbonyl group followed by dehydration to the Schiff base. The Schiff base is an electrophile which reacts in a second step in an electrophilic addition with an enol formed from a carbonyl compound containing an acidic alpha-proton. The Mann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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