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Pseudohalic
Pseudohalogens are polyatomic analogues of halogens, whose chemistry, resembling that of the true halogens, allows them to substitute for halogens in several classes of chemical compounds. Pseudohalogens occur in pseudohalogen molecules, inorganic molecules of the general forms ''Ps''–''Ps'' or ''Ps''–X (where ''Ps'' is a pseudohalogen group), such as cyanogen; pseudohalide anions, such as cyanide ion; inorganic acids, such as hydrogen cyanide; as ligands in coordination complexes, such as ferouscyanide; and as functional groups in organic molecules, such as the nitrile group. Well-known pseudohalogen functional groups include cyanide, cyanate, thiocyanate, and azide. Common pseudohalogens and their nomenclature Many pseudohalogens are known by specialized common names according to where they occur in a compound. Well-known ones include (the true halogen chlorine is listed for comparison): Au− is considered to be a pseudohalogen ion due to its disproportionation reactio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halogens
The halogens () are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). In the modern IUPAC nomenclature, this group is known as group 17. The word "halogen" means "salt former" (or "salt maker"). When halogens react with metals, they produce a wide range of salts, including calcium fluoride, sodium chloride (common table salt), silver bromide and potassium iodide. The group of halogens is the only periodic table group that contains elements in three of the main states of matter at standard temperature and pressure. All of the halogens form acids when bonded to hydrogen. Most halogens are typically produced from minerals or salts. The middle halogens—chlorine, bromine, and iodine—are often used as disinfectants. Organobromides are the most important class of flame retardants, while elemental halogens are dangerous and can be toxic. History The fluo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electron pairs, often through Lewis bases. The nature of metal–ligand bonding can range from covalent to ionic. Furthermore, the metal–ligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic "ligands". Metals and metalloids are bound to ligands in almost all circumstances, although gaseous "naked" metal ions can be generated in a high vacuum. Ligands in a complex dictate the reactivity of the central atom, including ligand substitution rates, the reactivity of the ligands themselves, and redox. Ligand selection requires critical consideration in many practical areas, including bioinorganic and medicinal chemistry, homogeneous catalysis, and environmental chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food, energy or organic micronutrients. Its chemical formula, H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. "Water" is also the name of the liquid state of H2O at standard temperature and pressure. A number of natural states of water exist. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor. Water co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%–6% by weight) in water for consumer use, and in higher concentrations for industrial use. Concentrated hydrogen peroxide, or " high-test peroxide", decomposes explosively when heated and has been used as a propellant in rocketry. Hydrogen peroxide is a reactive oxygen species and the simplest peroxide, a compound having an oxygen–oxygen single bond. It decomposes slowly when exposed to light, and rapidly in the presence of organic or reactive compounds. It is typically stored with a stabilizer in a weakly acidic solution in a dark bottle to block light. Hydrogen peroxide is found in biological systems including the human body. Enzymes that use or decompose hydrogen peroxide are classified as peroxidases. Properties The boiling poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxy Group
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion , called hydroxide, and the neutral radical , known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term ''hydroxyl'' refers to the hydroxyl radical () only, while the functional group is called a ''hydroxy group''. Properties Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isocyanide
An isocyanide (also called isonitrile or carbylamine) is an organic compound with the functional group –. It is the isomer of the related nitrile (–C≡N), hence the prefix is ''isocyano''.IUPAC Goldboo''isocyanides''/ref> The organic fragment is connected to the isocyanide group through the nitrogen atom, not via the carbon. They are used as building blocks for the synthesis of other compounds. Properties Structure and bonding The C-N distance in isocyanides is 115.8 pm in methyl isocyanide. The C-N-C angles are near 180°. Akin to carbon monoxide, isocyanides are described by two resonance structures, one with a triple bond between the nitrogen and the carbon and one with a double bond between. The π lone pair of the nitrogen stabilizes the structure and is responsible of the linearity of isocyanides, although the reactivity of isocyanides reflects some carbene character, at least in a formal sense. Thus, both resonance structures are useful representations. They are sus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isocyanide
An isocyanide (also called isonitrile or carbylamine) is an organic compound with the functional group –. It is the isomer of the related nitrile (–C≡N), hence the prefix is ''isocyano''.IUPAC Goldboo''isocyanides''/ref> The organic fragment is connected to the isocyanide group through the nitrogen atom, not via the carbon. They are used as building blocks for the synthesis of other compounds. Properties Structure and bonding The C-N distance in isocyanides is 115.8 pm in methyl isocyanide. The C-N-C angles are near 180°. Akin to carbon monoxide, isocyanides are described by two resonance structures, one with a triple bond between the nitrogen and the carbon and one with a double bond between. The π lone pair of the nitrogen stabilizes the structure and is responsible of the linearity of isocyanides, although the reactivity of isocyanides reflects some carbene character, at least in a formal sense. Thus, both resonance structures are useful representations. They are sus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Isocyanide
Hydrogen isocyanide is a chemical with the molecular formula HNC. It is a minor tautomer of hydrogen cyanide (HCN). Its importance in the field of astrochemistry is linked to its ubiquity in the interstellar medium. Nomenclature Both ''hydrogen isocyanide'' and ''azanylidyniummethanide'' are correct IUPAC names for HNC. There is no preferred IUPAC name. The second one is according to the ''substitutive nomenclature rules'', derived from the ''parent hydride'' azane () and the anion methanide (). Molecular properties Hydrogen isocyanide (HNC) is a linear triatomic molecule with C∞v point group symmetry. It is a zwitterion and an isomer of hydrogen cyanide (HCN). Both HNC and HCN have large, similar dipole moments, with ''μ''HNC = 3.05 Debye and ''μ''HCN = 2.98 Debye respectively. These large dipole moments facilitate the easy observation of these species in the interstellar medium. HNC−HCN tautomerism As HNC is higher in energy than HCN by 3920&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyaphide
Cyaphide, P≡C−, is the phosphorus analogue of cyanide. It is not known as a discrete salt, however ''In silico'' measurements reveal that the −1 charge in this ion is located mainly on carbon (0.65), as opposed to phosphorus. Preparation Organometallic complexes of cyaphide were first reported in 1992. More recent preparations use two other routes: From SiR3-functionalised phosphaalkynes Treatment of the η1-coordinated phosphaalkyne complex ''trans''– with an alkoxide resulted in desilylation, followed by subsequent rearrangement to the corresponding carbon-bound cyaphide complex. Cyaphide-alkynyl complexes are prepared similarly. From 2-phosphaethynolate anion (−OC≡P) An actinide cyaphide complex can be prepared by C−O bond cleavage of the phosphaethynolate anion, the phosphorus analogue of cyanate. Reaction of the uranium complex [] with [ in the presence of 2.2.2-cryptand results in the formation of a dinuclear, oxo-bridged uranium complex featuring a C≡P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methylidynephosphane
Methylidynephosphane (phosphaethyne) is a chemical compound which was the first phosphaalkyne compound discovered, containing the unusual C≡P carbon-phosphorus triple bond. Description Methylidynephosphane is the phosphorus analogue of hydrogen cyanide, with the nitrile nitrogen replaced by phosphorus. Methylidynephosphane can be synthesised via the reaction of phosphine with carbon, but it is extremely reactive and polymerises readily at temperatures above −120 °C. However, several types of derivatives, with bulky groups, such as ''tert''-butyl or trimethylsilyl, substituted for the hydrogen atom, are much more stable, and are useful reagents for the synthesis of various organophosphorus compounds. The PCO− and PCS− anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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