A metallocene is a compound typically consisting of two cyclopentadienyl anions (C
5H−
5, abbreviated Cp) bound to a metal center (M) in the oxidation state II, with the resulting general formula (C5H5)2M. Closely related to the metallocenes are the metallocene derivatives, e.g. titanocene dichloride or vanadocene dichloride. Certain metallocenes and their derivatives exhibit catalytic properties, although metallocenes are rarely used industrially. Cationic group 4 metallocene derivatives related to [Cp2ZrCH3]+ catalyze olefin polymerization.
Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and sometimes broadened to include metalloids like boron, silicon, and selenium, as well. Aside from bonds to organyl fragments or molecules, bonds to 'inorganic' carbon, like carbon monoxide, cyanide, or carbide, are generally considered to be organometallic as well. Some related compounds such as transition metal hydrides and metal phosphine complexes are often included in discussions of organometallic compounds, though strictly speaking, they are not necessarily organometallic. The related but distinct term "metalorganic compound" refers to metal-containing compounds lacking direct metal-carbon bonds but which contain organic ligands. Metal β-diketonates, alkoxides, dialkylamides, and metal phosphine complexes are representative members of this class. The field of organometallic chemistry combines aspects of traditional inorganic and organic chemistry.
Ferrocene is an organometallic compound with the formula Fe(C5H5)2. The molecule is a complex consisting of two cyclopentadienyl rings sandwiching a central iron atom. It is an orange solid with a camphor-like odor that sublimes above room temperature, and is soluble in most organic solvents. It is remarkable for its stability: it is unaffected by air, water, strong bases, and can be heated to 400 °C without decomposition. In oxidizing conditions it can reversibly react with strong acids to form the ferrocenium cation Fe(C5H5)+2. Ferrocene and the ferrocenium cation are sometimes abbreviated as Fc and Fc+ respectively.
Cobaltocene, known also as bis(cyclopentadienyl)cobalt(II) or even "bis Cp cobalt", is an organocobalt compound with the formula Co(C5H5)2. It is a dark purple solid that sublimes readily slightly above room temperature. Cobaltocene was discovered shortly after ferrocene, the first metallocene. Due to the ease with which it reacts with oxygen, the compound must be handled and stored using air-free techniques.
Hexamethylphosphoramide, often abbreviated HMPA, is a phosphoramide (an amide of phosphoric acid) with the formula [(CH3)2N]3PO. This colorless liquid is a useful reagent in organic synthesis.
The nitrosonium ion is NO+, in which the nitrogen atom is bonded to an oxygen atom with a bond order of 3, and the overall diatomic species bears a positive charge. It can be viewed as nitric oxide with one electron removed. This ion is usually obtained as the following salts: NOClO4, NOSO4H (nitrosylsulfuric acid, more descriptively written ONSO3OH) and NOBF4. The ClO−4 and BF−4 salts are slightly soluble in acetonitrile CH3CN. NOBF4 can be purified by sublimation at 200–250 °C and 0.01 mmHg (1.3 Pa).
In organometallic chemistry, a sandwich compound is a chemical compound featuring a metal bound by haptic, covalent bonds to two arene (ring) ligands. The arenes have the formula CnHn, substituted derivatives and heterocyclic derivatives. Because the metal is usually situated between the two rings, it is said to be "sandwiched". A special class of sandwich complexes are the metallocenes.
Silver hexafluorophosphate, sometimes referred to "silver PF-6," is an inorganic compound with the chemical formula AgPF6.
Organobismuth chemistry is the chemistry of organometallic compounds containing a carbon to bismuth chemical bond. Applications are few. The main bismuth oxidation states are Bi(III) and Bi(V) as in all higher group 15 elements. The energy of a bond to carbon in this group decreases in the order P > As > Sb > Bi. The first reported use of bismuth in organic chemistry was in oxidation of alcohols by Frederick Challenger in 1934 (using Ph3Bi(OH)2). Knowledge about methylated species of bismuth in environmental and biological media is limited.
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.
Ferrocenium tetrafluoroborate is an organometallic compound with the formula [Fe(C5H5)2]BF4. This salt is composed of the cation [Fe(C5H5)2]+ and the tetrafluoroborate anion (BF−
4). The related hexafluorophosphate is also a popular reagent with similar properties. The ferrocenium cation is often abbreviated Fc+ or Cp2Fe+. The salt is deep blue in color and paramagnetic. Ferrocenium salts are sometimes used as one-electron oxidizing agents, and the reduced product, ferrocene, is inert and readily separated from ionic products. The ferrocene–ferrocenium couple is often used as a reference in electrochemistry. The standard potential of ferrocene-ferrocenium is dependent on specific electrochemical conditions.
Nitrosonium tetrafluoroborate, also called nitrosyl tetrafluoroborate, is a chemical compound with the chemical formula NOBF4. This colourless solid is used in organic synthesis as a nitrosating agent.
Organosilver chemistry is the study of organometallic compounds containing a carbon to silver chemical bond. The theme is less developed than organocopper chemistry.
Ruthenium(III) acetylacetonate is a coordination complex with the formula Ru(O2C5H7)3. O2C5H7− is the ligand called acetylacetonate. This compound exists as a dark violet solid that is soluble in most organic solvents. It is used as a precursor to other compounds of ruthenium.
Ferrocenium hexafluorophosphate is an organometallic compound with the formula [Fe(C5H5)2]PF6. This salt is composed of the cation [Fe(C5H5)2]+ and the hexafluorophosphate anion (PF−
6). The related tetrafluoroborate is also a popular reagent with similar properties. The ferrocenium cation is often abbreviated Fc+ or Cp2Fe+. The salt is deep blue in color and paramagnetic.
Rhodocene is a chemical compound with the formula [Rh(C5H5)2]. Each molecule contains an atom of rhodium bound between two planar aromatic systems of five carbon atoms known as cyclopentadienyl rings in a sandwich arrangement. It is an organometallic compound as it has (haptic) covalent rhodium–carbon bonds. The [Rh(C5H5)2] radical is found above 150 °C (302 °F) or when trapped by cooling to liquid nitrogen temperatures (−196 °C [−321 °F]). At room temperature, pairs of these radicals join via their cyclopentadienyl rings to form a dimer, a yellow solid.
Decamethylferrocene or bis(pentamethylcyclopentadienyl)iron(II) is a chemical compound with formula Fe(C5(CH3)5)2 or C20H30Fe. It is a sandwich compound, whose molecule has an iron(II) cation Fe2+ attached by coordination bonds between two pentamethylcyclopentadienyl anions (Cp*−, (CH3)5C−5). It can also be viewed as a derivative of ferrocene, with a methyl group replacing each hydrogen atom of its cyclopentadienyl rings. The name and formula are often abbreviated to DmFc, Me10Fc or FeCp*2.
Tris(trimethylsilyl)amine is the simplest tris(trialkylsilyl)amine which are having the general formula (R3Si)3N, in which all three hydrogen atoms of the ammonia are replaced by trimethylsilyl groups (-Si(CH3)3). Tris(trimethylsilyl)amine has been for years in the center of scientific interest as a stable intermediate in chemical nitrogen fixation (i. e. the conversion of atmospheric nitrogen N2 into organic substrates under normal conditions).
Transition metal nitrile complexes are coordination compounds containing nitrile ligands. Because nitriles are weakly basic, the nitrile ligands in these complexes are often labile.
Ferrocenecarboxylic acid is the organoiron compound with the formula (C5H5)Fe(C5H4CO2H). It is the simplest carboxylic acid derivative of ferrocene. It can be prepared in two steps from ferrocene by acylation with a 2-chlorobenzoyl chloride followed by hydrolysis.
