Group 9, by modern IUPAC numbering, is a group (column) of chemical elements in the d-block of the periodic table. Members of Group 9 include cobalt (Co), rhodium (Rh), iridium (Ir) and meitnerium (Mt). These elements are among the rarest of the transition metals.
In organic chemistry, an allyl group is a substituent with the structural formula −CH2−HC=CH2. It consists of a methylene bridge attached to a vinyl group. The name is derived from the scientific name for garlic, Allium sativum. In 1844, Theodor Wertheim isolated an allyl derivative from garlic oil and named it "Schwefelallyl". The term allyl applies to many compounds related to H2C=CH−CH2, some of which are of practical or of everyday importance, for example, allyl chloride.
Cobalt(II) chloride is an inorganic compound, a salt of cobalt and chlorine, with the formula CoCl
2. The compound forms several hydrates CoCl
2·nH
2O, for n = 1, 2, 6, and 9. Claims of the formation of tri- and tetrahydrates have not been confirmed. The anhydrous form is a blue crystalline solid; the dihydrate is purple and the hexahydrate is pink. Commercial samples are usually the hexahydrate, which is one of the most commonly used cobalt salts in the lab.
In coordination chemistry, metal ammine complexes are metal complexes containing at least one ammonia ligand. "Ammine" is spelled this way for historical reasons; in contrast, alkyl or aryl bearing ligands are spelt with a single "m". Almost all metal ions bind ammonia as a ligand, but the most prevalent examples of ammine complexes are for Cr(III), Co(III), Ni(II), Cu(II) as well as several platinum group metals.
Cobalt(III) fluoride is the inorganic compound with the formula CoF3. Hydrates are also known. The anhydrous compound is a hygroscopic brown solid. It is used to synthesize organofluorine compounds.
The 18-electron rule is a chemical rule of thumb used primarily for predicting and rationalizing formulas for stable transition metal complexes, especially organometallic compounds. The rule is based on the fact that the valence orbitals in the electron configuration of transition metals consist of five (n−1)d orbitals, one ns orbital, and three np orbitals, where n is the principal quantum number. These orbitals can collectively accommodate 18 electrons as either bonding or non-bonding electron pairs. This means that the combination of these nine atomic orbitals with ligand orbitals creates nine molecular orbitals that are either metal-ligand bonding or non-bonding. When a metal complex has 18 valence electrons, it is said to have achieved the same electron configuration as the noble gas in the period, lending stability to the complex. Transition metal complexes that deviate from the rule are often interesting or useful because they tend to be more reactive. The rule is not helpful for complexes of metals that are not transition metals. The rule was first proposed by American chemist Irving Langmuir in 1921.
Cobalt(II) oxide is an inorganic compound that has been described as an olive-green or gray solid. It is used extensively in the ceramics industry as an additive to create blue-colored glazes and enamels, as well as in the chemical industry for producing cobalt(II) salts. A related material is cobalt(II,III) oxide, a black solid with the formula Co3O4.
Dioxygen complexes are coordination compounds that contain O2 as a ligand. The study of these compounds is inspired by oxygen-carrying proteins such as myoglobin, hemoglobin, hemerythrin, and hemocyanin. Several transition metals form complexes with O2, and many of these complexes form reversibly. The binding of O2 is the first step in many important phenomena, such as cellular respiration, corrosion, and industrial chemistry. The first synthetic oxygen complex was demonstrated in 1938 with cobalt(II) complex reversibly bound O2.
Organorhodium chemistry is the chemistry of organometallic compounds containing a rhodium-carbon chemical bond, and the study of rhodium and rhodium compounds as catalysts in organic reactions.
Cobalt(III) chloride or cobaltic chloride is an unstable and elusive compound of cobalt and chlorine with formula CoCl
3. In this compound, the cobalt atoms have a formal charge of +3.
Nickel(II) perchlorate is a inorganic compound with the chemical formula of Ni(ClO4)2, and it is a strong oxidizing agent. Its colors are different depending on water. For example, the hydrate forms cyan crystals, the pentahydrate forms green crystals, but the hexahydrate (Ni(ClO4)2·6H2O) forms blue crystals.
Cobalt compounds are chemical compounds formed by cobalt with other elements.
Tin(II) stearate is a metal-organic compound with the chemical formula C
18H
36SnO
2. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid.
Copper(II) stearate is a metal-organic compound, a salt of copper and stearic acid with the formula Cu(C17H35COO)2. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid.
Mercury(II) stearate is a metal-organic compound, a salt of mercury and stearic acid with the chemical formula C
36H
70HgO
4. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid. The compound is highly toxic by inhalation, ingestion, and skin absorption.
Nickel(II) stearate is a metal-organic compound, a salt of nickel and stearic acid with the chemical formula C
36H
70NiO
4. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid. The compound is harmful if swallowed and may cause skin sensitization.
Strontium stearate is a metal-organic compound, a salt of strontium and stearic acid with the chemical formula C
36H
70SrO
4. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid.
Manganese stearate is a metal-organic compound, a salt of manganese and stearic acid with the chemical formula C
36H
70MnO
4. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid.
Lead stearate is a metal-organic compound, a salt of lead and stearic acid with the chemical formula C
36H
70PbO
4. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid. The compound is toxic.
Caesium stearate is a metal-organic compound, a salt of caesium and stearic acid with the chemical formula C
18H
35CsO
2. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid.
