|
Hexaamminecobalt(III) Chloride
Hexaamminecobalt(III) chloride is the chemical compound with the formula o(NH3)6l3. It is the chloride salt of the coordination complex o(NH3)6sup>3+, which is considered an archetypal "Werner complex", named after the pioneer of coordination chemistry, Alfred Werner. The cation itself is a metal ammine complex with six ammonia ligands attached to the cobalt(III) ion. Originally salts of o(NH3)6sup>3+ were described as the ''luteo'' (Latin: yellow) complex of cobalt. This name has been discarded as modern chemistry considers color less important than molecular structure. Other similar complexes also had color names, such as ''purpureo'' (Latin: purple) for a cobalt pentammine complex, and ''praseo'' (Greek: green) and ''violeo'' (Latin: violet) for two isomeric tetrammine complexes. Properties and structure o(NH3)6sup>3+ is diamagnetic, with a low-spin 3d6 octahedral Co(III) center. The cation obeys the 18-electron rule and is considered to be a classic example of an ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octahedral
In geometry, an octahedron (plural: octahedra, octahedrons) is a polyhedron with eight faces. The term is most commonly used to refer to the regular octahedron, a Platonic solid composed of eight equilateral triangles, four of which meet at each vertex. A regular octahedron is the dual polyhedron of a cube. It is a rectified tetrahedron. It is a square bipyramid in any of three orthogonal orientations. It is also a triangular antiprism in any of four orientations. An octahedron is the three-dimensional case of the more general concept of a cross polytope. A regular octahedron is a 3-ball in the Manhattan () metric. Regular octahedron Dimensions If the edge length of a regular octahedron is ''a'', the radius of a circumscribed sphere (one that touches the octahedron at all vertices) is :r_u = \frac a \approx 0.707 \cdot a and the radius of an inscribed sphere (tangent to each of the octahedron's faces) is :r_i = \frac a \approx 0.408\cdot a while the midradius, which t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to 45% of the world's food and fertilizers. Around 70% of ammonia is used to make fertilisers in various forms and composition, such as urea and Diammonium phosphate. Ammonia in pure form is also applied directly into the soil. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical products and is used in many commercial cleaning products. It is mainly collected by downward displacement of both air and water. Although common in nature—both terrestrially and in the outer planets of the Solar System—and in wide use, ammonia is both caust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant materials, and cell stains. Although uncommon, chronic toxicity from bromide can result in bromism, a syndrome with multiple neurological symptoms. Bromide toxicity can also cause a type of skin eruption, see potassium bromide. The bromide ion has an ionic radius of 196 pm. Natural occurrence Bromide is present in typical seawater (35 PSU) with a concentration of around 65 mg/L, which is about 0.2% of all dissolved salts. Seafood and deep sea plants generally have higher levels than land-derived foods. Bromargyrite—natural, crystalline silver bromide—is the most common bromide mineral known but is still very rare. In addition to silver, bromine is also in minerals combined with mercury and copper. Formation and react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrate
Nitrate is a polyatomic ion A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zero. The term molecule may or may no ... with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in water. An example of an insoluble nitrate is bismuth oxynitrate. Structure The ion is the conjugate acid, conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a formal charge of −1. This charge results from a combination formal charge in which each of the three oxygens carries a − charge, whereas the nitrogen carries a +1 charge, all these adding up to formal c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lability
Lability refers to something that is constantly undergoing change or is likely to undergo change. Biochemistry In reference to biochemistry, this is an important concept as far as kinetics is concerned in metalloproteins. This can allow for the rapid synthesis and degradation of substrates in biological systems. Biology Cells Labile cells refer to cells that constantly divide by entering and remaining in the cell cycle. These are contrasted with "stable cells" and "permanent cells". An important example of this is in the epithelium of the cornea, where cells divide at the basal level and move upwards, and the topmost cells die and fall off. Proteins In medicine, the term "labile" means susceptible to alteration or destruction. For example, a heat-labile protein is one that can be changed or destroyed at high temperatures. The opposite of labile in this context is "stable". Soils Compounds or materials that are easily transformed (often by biological activity) are termed ... [...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] |
Octahedral Molecular Geometry
In chemistry, octahedral molecular geometry, also called square bipyramidal, describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron. The octahedron has eight faces, hence the prefix ''octa''. The octahedron is one of the Platonic solids, although octahedral molecules typically have an atom in their centre and no bonds between the ligand atoms. A perfect octahedron belongs to the point group Oh. Examples of octahedral compounds are sulfur hexafluoride SF6 and molybdenum hexacarbonyl Mo(CO)6. The term "octahedral" is used somewhat loosely by chemists, focusing on the geometry of the bonds to the central atom and not considering differences among the ligands themselves. For example, , which is not octahedral in the mathematical sense due to the orientation of the bonds, is referred to as octahedral. The concept of octahedral coordination geometry was developed by Alfred Wern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand Field Theory
Ligand field theory (LFT) describes the bonding, orbital arrangement, and other characteristics of coordination complexes. It represents an application of molecular orbital theory to transition metal complexes. A transition metal ion has nine valence atomic orbitals - consisting of five ''n''d, one (''n''+1)s, and three (''n''+1)p orbitals. These orbitals are of appropriate energy to form bonding interaction with ligands. The LFT analysis is highly dependent on the geometry of the complex, but most explanations begin by describing octahedral complexes, where six ligands coordinate to the metal. Other complexes can be described by reference to crystal field theory.G. L. Miessler and D. A. Tarr "Inorganic Chemistry" 3rd Ed, Pearson/Prentice Hall publisher, . History Ligand field theory resulted from combining the principles laid out in molecular orbital theory and crystal field theory, which describes the loss of degeneracy of metal d orbitals in transition metal complexes. John Sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomeric
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural or constitutional isomerism, in which ''bonds'' between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different isotopologues. The depth of analysis depends on the field of study or the chemical and physical properties of interest. The English word "isomer" () is a back-for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
-3D-balls.png "Click for more on -> Ammonia")
