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Phenanthroline
1,10-Phenanthroline (phen) is a heterocyclic organic compound. It is a white solid that is soluble in organic solvents. The 1,10 refer to the location of the nitrogen atoms that replace CH's in the hydrocarbon called phenanthrene. Abbreviated "phen", it is used as a ligand in coordination chemistry, forming strong complexes with most metal ions.Luman, C.R. and Castellano, F.N. (2003) "Phenanthroline Ligands" in Comprehensive Coordination Chemistry II. Elsevier. . It is often sold as the monohydrate. Synthesis Phenanthroline may be prepared by two successive Skraup reactions of glycerol with ''o''-phenylenediamine, catalyzed by sulfuric acid, and an oxidizing agent, traditionally aqueous arsenic acid or nitrobenzene. Dehydration of glycerol gives acrolein which condenses with the amine followed by a cyclization. Coordination chemistry In terms of its coordination properties, phenanthroline is similar to 2,2'-bipyridine (bipy) with the advantage that the two nitrogen don ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenanthroline Numbering
1,10-Phenanthroline (phen) is a heterocyclic organic compound. It is a white solid that is soluble in organic solvents. The 1,10 refer to the location of the nitrogen atoms that replace CH's in the hydrocarbon called phenanthrene. Abbreviated "phen", it is used as a ligand in coordination chemistry, forming strong complexes with most metal ions.Luman, C.R. and Castellano, F.N. (2003) "Phenanthroline Ligands" in Comprehensive Coordination Chemistry II. Elsevier. . It is often sold as the monohydrate. Synthesis Phenanthroline may be prepared by two successive Skraup reactions of glycerol with ''o''-phenylenediamine, catalyzed by sulfuric acid, and an oxidizing agent, traditionally aqueous arsenic acid or nitrobenzene. Dehydration of glycerol gives acrolein which condenses with the amine followed by a cyclization. Coordination chemistry In terms of its coordination properties, phenanthroline is similar to 2,2'-bipyridine (bipy) with the advantage that the two nitrogen donors a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neocuproine
Neocuproine is a heterocyclic organic compound and chelating agent. Phenanthroline ligands were first published in the late 19th century, and the derivatives substituted at the 2 and 9 positions are among the most studied of the modified phenanthrolines. Synthesis and structure Neocuproine can be prepared by sequential Skraup reactions ( Doebner-Miller reaction/condensation) of o-nitroaniline ( 2-Nitroaniline) with crotonaldehyde diacetate. An alternate synthesis involves the condensation of o-phenylenediamine, m-nitrobenzenesulphonate, and crotonaldehyde diacetate. This method gives higher yields but is less economical. Neocuproine crystallizes as a dihydrate and a hemihydrate. Coordination chemistry In the early 1930s, phenanthroline derivatives became known for their use as colorimetric indicators for many transition metals. Neocuproine proved to be highly selective for copper(I). The resulting complex, u(neocuproine)2sup>+ has a deep orange-red color. The properties of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathocuproine
Bathocuproine is a derivative of 1,10-phenanthroline with two methyl groups and two phenyl groups in the 2,9 and 4,7 positions, respectively. Like 1,10-phenanthroline, bathocuproine is a bidentate chelating ligand. The two methyl groups flank the nitrogen centers, such that bathocuproine is a bulky 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 electro .... It is a pale yellow solid that is soluble in polar organic solvents.{{cite encyclopedia, author=Guosheng Liu, Yichen, Wu, year=2012, title = Encyclopedia of Reagents for Organic Synthesis, doi=10.1002/047084289X.rn01392, encyclopedia=eEROS, chapter=Bathocuproine, isbn=978-0471936237 References Chelating agents Phenanthrolines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathocuproine
Bathocuproine is a derivative of 1,10-phenanthroline with two methyl groups and two phenyl groups in the 2,9 and 4,7 positions, respectively. Like 1,10-phenanthroline, bathocuproine is a bidentate chelating ligand. The two methyl groups flank the nitrogen centers, such that bathocuproine is a bulky 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 electro .... It is a pale yellow solid that is soluble in polar organic solvents.{{cite encyclopedia, author=Guosheng Liu, Yichen, Wu, year=2012, title = Encyclopedia of Reagents for Organic Synthesis, doi=10.1002/047084289X.rn01392, encyclopedia=eEROS, chapter=Bathocuproine, isbn=978-0471936237 References Chelating agents Phenanthrolines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferroin
Ferroin is the chemical compound with the formula e(''o''-phen)3O4, where ''o''-phen is an abbreviation for 1,10- phenanthroline, a bidentate ligand. The term "ferroin" is used loosely and includes salts of other anions such as chloride. Redox indicator This coordination compound is used as an indicator in analytical chemistry. The active ingredient is the e(''o''-phen)3sup>2+ ion, which is a chromophore that can be oxidized to the ferric derivative e(''o''-phen)3sup>3+. The potential for this redox change is +1.06 volts in 1 M H2SO4. It is a popular redox indicator for visualizing oscillatory Belousov–Zhabotinsky reactions. Ferroin is suitable as a redox indicator, as the color change is reversible, very pronounced and rapid, and the ferroin solution is stable up to 60 °C. It is the main indicator used in cerimetry.{{cite book, title=Handbook on the Physics and Chemistry of Rare Earths, url=https://books.google.com/books?id=_Ro3Fqtz4xgC&pg=PA289, date= 200 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redox Indicator
A redox indicator (also called an oxidation-reduction indicator) is an indicator which undergoes a definite color change at a specific electrode potential. The requirement for fast and reversible color change means that the oxidation-reduction equilibrium for an indicator redox system needs to be established very quickly. Therefore, only a few classes of organic redox systems can be used for indicator purposes. There are two common classes of redox indicators: * metal complexes of phenanthroline and bipyridine. In these systems, the metal changes oxidation state. * organic redox systems such as methylene blue. In these systems, a proton participant in the redox reaction. Therefore, sometimes redox indicators are also divided into two general groups: independent or dependent on pH. The most common redox indicator are organic compounds. Redox Indicator example: The molecule 2,2'- Bipyridine is a redox Indicator. In solution, it changes from light blue to red at an electrode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grignard Reagents
A Grignard reagent or Grignard compound is a chemical compound with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide . They are a subclass of the organomagnesium compounds. Grignard compounds are popular reagents in organic synthesis for creating new carbon-carbon bonds. For example, when reacted with another halogenated compound in the presence of a suitable catalyst, they typically yield and the magnesium halide as a byproduct; and the latter is insoluble in the solvents normally used. In this aspect, they are similar to organolithium reagents. Pure Grignard reagents are extremely reactive solids. They are normally handled as solutions in solvents such as diethyl ether or tetrahydrofuran; which are relatively stable as long as water is excluded. In such a medium, a Grignard reagent is invariably present as a complex with the magnesium atom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenanthrene
Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) with formula C14H10, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics and pesticides, explosives and drugs. It has also been used to make bile acids, cholesterol and steroids. Phenanthrene occurs naturally and also is a man-made chemical. Commonly, humans are exposed to phenanthrene through inhalation of cigarette smoke but there are many routes of exposure. Animal studies have shown that phenanthrene is a potential carcinogen. However, according to IARC, it is not identified as a probable, possible or confirmed human carcinogen. Phenanthrene's three fused rings are angled as in the phenacenes, rather than straight as in the acenes. The compound with a phenanthrene skeleton and nitrogens at the 4 and 5 positions is known as phenanthroline. Chemistry Phenanthrene is nearly insoluble in water but is soluble in most low p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallopeptidase
A metalloproteinase, or metalloprotease, is any protease enzyme whose catalytic mechanism involves a metal. An example is ADAM12 which plays a significant role in the fusion of muscle cells during embryo development, in a process known as myogenesis. Most metalloproteases require zinc, but some use cobalt. The metal ion is coordinated to the protein via three ligands. The ligands coordinating the metal ion can vary with histidine, glutamate, aspartate, lysine, and arginine. The fourth coordination position is taken up by a labile water molecule. Treatment with chelating agents such as EDTA leads to complete inactivation. EDTA is a metal chelator that removes zinc, which is essential for activity. They are also inhibited by the chelator orthophenanthroline. Classification There are two subgroups of metalloproteinases: * Exopeptidases, metalloexopeptidases ( EC number: 3.4.17). * Endopeptidases, metalloendopeptidases (3.4.24). Well known metalloendopeptidases include ADAM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group (these may respectively be called alkylamines and arylamines; amines in which both types of substituent are attached to one nitrogen atom may be called alkylarylamines). Important amines include amino acids, biogenic amines, trimethylamine, and aniline; Inorganic derivatives of ammonia are also called amines, such as monochloramine (). The substituent is called an amino group. Compounds with a nitrogen atom attached to a carbonyl group, thus having the structure , are called amides and have different chemical properties from amines. Classification of amines Amines can be classified according to the nature and number of substituents on nitrogen. Aliphatic amines contain only H and alkyl substitue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endpoint (chemistry)
The equivalence point, or stoichiometric point, of a chemical reaction is the point at which chemically equivalent quantities of reactants have been mixed. For an acid-base reaction the equivalence point is where the moles of acid and the moles of base would neutralize each other according to the chemical reaction. This does not necessarily imply a 1:1 molar ratio of acid:base, merely that the ratio is the same as in the chemical reaction. It can be found by means of an indicator, for example phenolphthalein or methyl orange. The endpoint (related to, but not the same as the equivalence point) refers to the point at which the indicator changes color in a colorimetric titration. Methods to determine the equivalence point Different methods to determine the equivalence point include: ;pH indicator: A pH indicator is a substance that changes color in response to a chemical change. An acid-base indicator (e.g., phenolphthalein) changes color depending on the pH. Redox indicators are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
