Alkynes: Hydrocarbons with at least one triple bond in the linear portion, of the general formula Cn-H2n-2.Metals: Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)Transition Elements: Elements with partially filled d orbitals. They constitute groups 3-12 of the periodic table of elements.Ticlopidine: An effective inhibitor of platelet aggregation commonly used in the placement of STENTS in CORONARY ARTERIES.Platelet Aggregation Inhibitors: Drugs or agents which antagonize or impair any mechanism leading to blood platelet aggregation, whether during the phases of activation and shape change or following the dense-granule release reaction and stimulation of the prostaglandin-thromboxane system.Rhodium: Rhodium. A hard and rare metal of the platinum group, atomic number 45, atomic weight 102.905, symbol Rh. (Dorland, 28th ed)Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Cyclization: Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Copper: A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.Nickel: A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.Click Chemistry: Organic chemistry methodology that mimics the modular nature of various biosynthetic processes. It uses highly reliable and selective reactions designed to "click" i.e., rapidly join small modular units together in high yield, without offensive byproducts. In combination with COMBINATORIAL CHEMISTRY TECHNIQUES, it is used for the synthesis of new compounds and combinatorial libraries.Cobalt: A trace element that is a component of vitamin B12. It has the atomic symbol Co, atomic number 27, and atomic weight 58.93. It is used in nuclear weapons, alloys, and pigments. Deficiency in animals leads to anemia; its excess in humans can lead to erythrocytosis.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Alkenes: Unsaturated hydrocarbons of the type Cn-H2n, indicated by the suffix -ene. (Grant & Hackh's Chemical Dictionary, 5th ed, p408)Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Zinc: A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Chelating Agents: Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.Manganese: A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)Organometallic Compounds: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)Coordination Complexes: Neutral or negatively charged ligands bonded to metal cations or neutral atoms. The number of ligand atoms to which the metal center is directly bonded is the metal cation's coordination number, and this number is always greater than the regular valence or oxidation number of the metal. A coordination complex can be negative, neutral, or positively charged.Metals, Alkaline Earth: Metals that constitute the group 2 (formerly group IIa) of the periodic table.Alkadienes: Acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds.Ruthenium: A hard, brittle, grayish-white rare earth metal with an atomic symbol Ru, atomic number 44, and atomic weight 101.07. It is used as a catalyst and hardener for PLATINUM and PALLADIUM.Iron: A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.Cations, Divalent: Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.Palladium: A chemical element having an atomic weight of 106.4, atomic number of 46, and the symbol Pd. It is a white, ductile metal resembling platinum, and following it in abundance and importance of applications. It is used in dentistry in the form of gold, silver, and copper alloys.Azides: Organic or inorganic compounds that contain the -N3 group.Propanols: Isomeric forms and derivatives of PROPANOL (C3H7OH).Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Cycloparaffins: Alicyclic hydrocarbons in which three or more of the carbon atoms in each molecule are united in a ring structure and each of the ring carbon atoms is joined to two hydrogen atoms or alkyl groups. The simplest members are cyclopropane (C3H6), cyclobutane (C4H8), cyclohexane (C6H12), and derivatives of these such as methylcyclohexane (C6H11CH3). (From Sax, et al., Hawley's Condensed Chemical Dictionary, 11th ed)Ions: An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Chemistry, Organic: The study of the structure, preparation, properties, and reactions of carbon compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Kinetics: The rate dynamics in chemical or physical systems.Metals, Heavy: Metals with high specific gravity, typically larger than 5. They have complex spectra, form colored salts and double salts, have a low electrode potential, are mainly amphoteric, yield weak bases and weak acids, and are oxidizing or reducing agents (From Grant & Hackh's Chemical Dictionary, 5th ed)Amination: The creation of an amine. It can be produced by the addition of an amino group to an organic compound or reduction of a nitro group.IminesCycloaddition Reaction: Synthetic organic reactions that use reactions between unsaturated molecules to form cyclical products.Heterocyclic Compounds: Ring compounds having atoms other than carbon in their nuclei. (Grant & Hackh's Chemical Dictionary, 5th ed)Gold: A yellow metallic element with the atomic symbol Au, atomic number 79, and atomic weight 197. It is used in jewelry, goldplating of other metals, as currency, and in dental restoration. Many of its clinical applications, such as ANTIRHEUMATIC AGENTS, are in the form of its salts.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Chromium: A trace element that plays a role in glucose metabolism. It has the atomic symbol Cr, atomic number 24, and atomic weight 52. According to the Fourth Annual Report on Carcinogens (NTP85-002,1985), chromium and some of its compounds have been listed as known carcinogens.Metals, Alkali: Metals that constitute group 1(formerly group Ia) of the periodic table. They are the most strongly electropositive of the metals. Note that HYDROGEN is not considered an alkali metal even though it falls under the group 1 heading in the periodic table.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Ferrous Compounds: Inorganic or organic compounds that contain divalent iron.Aldehydes: Organic compounds containing a carbonyl group in the form -CHO.Vanadium: A metallic element with the atomic symbol V, atomic number 23, and atomic weight 50.94. It is used in the manufacture of vanadium steel. Prolonged exposure can lead to chronic intoxication caused by absorption usually via the lungs.Trientine: An ethylenediamine derivative used as stabilizer for EPOXY RESINS, as ampholyte for ISOELECTRIC FOCUSING and as chelating agent for copper in HEPATOLENTICULAR DEGENERATION.Vinyl CompoundsPhosphines: Inorganic or organic compounds derived from phosphine (PH3) by the replacement of H atoms. (From Grant & Hackh's Chemical Dictionary, 5th ed)Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Quantum Theory: The theory that the radiation and absorption of energy take place in definite quantities called quanta (E) which vary in size and are defined by the equation E=hv in which h is Planck's constant and v is the frequency of the radiation.Silanes: Compounds similar to hydrocarbons in which a tetravalent silicon atom replaces the carbon atom. They are very reactive, ignite in air, and form useful derivatives.Indolizidines: Saturated indolizines that are fused six and five-membered rings with a nitrogen atom at the ring fusion. They are biosynthesized in PLANTS by cyclization of a LYSINE coupled to ACETYL COENZYME A. Many of them are naturally occurring ALKALOIDS.Epithelial-Mesenchymal Transition: Phenotypic changes of EPITHELIAL CELLS to MESENCHYME type, which increase cell mobility critical in many developmental processes such as NEURAL TUBE development. NEOPLASM METASTASIS and DISEASE PROGRESSION may also induce this transition.Manganese Compounds: Inorganic chemicals that contain manganese as an integral part of the molecule.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Organogold Compounds: Organic compounds that contain GOLD as an integral part of the molecule. Some are used as ANTIRHEUMATIC AGENTS. The term chrysotherapy derives from an ancient Greek term for gold.KetonesOrganosilicon Compounds: Organic compounds that contain silicon as an integral part of the molecule.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Isocyanates: Organic compounds that contain the -NCO radical.Hempa: A chemosterilant agent that is anticipated to be a carcinogen.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Thermodynamics: A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Diynes: Compounds with two triple bonds. Some of them are CYTOTOXINS.Andropogon: A plant genus of the family POACEAE. The common name of bluestem is also used for other plants in this family. Andropogon nardus has been reclassified as CYMBOPOGON nardus and Andropogon zizanioides to VETIVERIA zizanioides.PhenanthrolinesCations: Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Combinatorial Chemistry Techniques: A technology, in which sets of reactions for solution or solid-phase synthesis, is used to create molecular libraries for analysis of compounds on a large scale.Molybdenum: A metallic element with the atomic symbol Mo, atomic number 42, and atomic weight 95.94. It is an essential trace element, being a component of the enzymes xanthine oxidase, aldehyde oxidase, and nitrate reductase. (From Dorland, 27th ed)EthylenediaminesMagnesium: A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.Gallium: A rare, metallic element designated by the symbol, Ga, atomic number 31, and atomic weight 69.72.Sulfhydryl Compounds: Compounds containing the -SH radical.Silica Gel: A non-crystalline form of silicon oxide that has absorptive properties. It is commonly used as a desiccating agent and as a stationary phase for CHROMATOGRAPHY. The fully hydrated form of silica gel has distinct properties and is referred to as SILICIC ACID.Phase Transition: A change of a substance from one form or state to another.Hydroxyl Radical: The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.Cadmium: An element with atomic symbol Cd, atomic number 48, and atomic weight 114. It is a metal and ingestion will lead to CADMIUM POISONING.Tungsten: Tungsten. A metallic element with the atomic symbol W, atomic number 74, and atomic weight 183.85. It is used in many manufacturing applications, including increasing the hardness, toughness, and tensile strength of steel; manufacture of filaments for incandescent light bulbs; and in contact points for automotive and electrical apparatus.
... es are most common for the early transition metals, especially niobium, tantalum, molybdenum, ... Metal alkylidyne complexes have mainly been used for specialized reactions in the laboratory, the main used being alkyne ... Many cluster-bound carbyne complexes are known, typically with CO ligands. These compounds do not feature MC triple bonds; ... In a Fischer carbyne the C-carbyne exhibits electrophilic behavior while Schrock carbynes display nucleophilic reactivity on ...
Two is added for every lone pair bonding to the metal (e.g. each phosphine ligand can bind with a lone pair). Similarly Lewis ... One counts valence electrons for main group elements differently from transition metals. E.g. in period 2: B, C, N, O, and F ... each Lewis base binds with a lone pair). Unsaturated hydrocarbons such as alkenes and alkynes are considered Lewis bases. ... electron counting is an important tool for identifying the reactivity of molecules. Two methods of electron counting are ...
The group 11 metals (or coinage metals), copper, silver, and gold, are typically categorised as transition metals given they ... and alkynes, the last demonstrating the phenomenal degree of their reactivity. Their great power as reducing agents makes them ... Sodium tetraphenylborate can also be classified as an organosodium compound since in the solid state sodium is bound to the ... "s-block Metal-Metal Bonds". In Liddle, Stephen T. Molecular Metal-Metal Bonds: Compounds, Synthesis, Properties. John Wiley and ...
Many metal-containing compounds, especially those of transition metals, are coordination complexes. A coordination complex ... the ions would bind via the ammonia chains Blomstrand had described or the ions would bind directly to the metal. It was not ... In contrast, coordination chemistry focuses on reactivity and properties of complexes containing individual metal atoms or ... alkynes, alkyls) as well as "organic-like" ligands such as phosphines, hydride, and CO. Example: (C5H5)Fe(CO)2CH3 Bioinorganic ...
ReactivityEdit. Main article: Reactivity (chemistry). The reactivities of the alkali metals increase going down the group. This ... The group 11 metals (or coinage metals), copper, silver, and gold, are typically categorised as transition metals given they ... The alkali metal peroxides are ionic compounds that are unstable in water. The peroxide anion is weakly bound to the cation, ... The alkali metals and their hydrides react with acidic hydrocarbons, for example cyclopentadienes and terminal alkynes, to give ...
... binds well to most transition metals, especially those in the middle and late transition metals of groups 7- ... Stryker's reagent, [(PPh3)CuH]6, PPh3-stabilized transition metal hydride cluster that used as a reagent for "conjugate ... The nucleophilicity of PPh3 is indicated by its reactivity toward electrophilic alkenes, such as Michael-acceptors, and alkyl ... 2 was used by Walter Reppe for the synthesis of acrylate esters from alkynes, carbon monoxide, and alcohols. Wilkinson's ...
One obstacle to the use of Shvo's catalyst in the hydrogenation of alkynes is its propensity to bind the alkyne quite tightly, ... The proposed alternatives are an inner-sphere mechanism, where the transition state involves interaction with the metal only, ... industrial hydrogenation processes involve heterogeneous catalysts containing one or more transition metals. While this ... further examination in the area has revealed ways to tailor reactivity of the complex to achieve desired outcomes. The most ...
Many metal-containing compounds, especially those of transition metals, are coordination complexes.[4] A coordination complex ... the ions would bind via the ammonia chains Blomstrand had described or the ions would bind directly to the metal. ... Reactivity[edit]. Complexes show a variety of possible reactivities:[22] *Electron transfers A common reaction between ... Organometallic Chemistry: Ligands are organic (alkenes, alkynes, alkyls) as well as "organic-like" ligands such as phosphines, ...
The examples of late transition metal hydrophosphination catalysts generally work on activated substrates (alkenes and alkynes ... phosphines can be used to tune the electronic and steric characteristics of the metals they bind to. Their most important ... The following reactivity varies from the other late metal catalysts in that P-C bond forming step involves a [2+2] ... early metals. Since many of the transition metal catalysts that are involved in hydrophosphination employ a phosphido ...
In certain transition metal-arene complexes, such as ferrocenes, the transition metal attracts electron-density from the arene ... and the transition state is not as tightly bound as a six-membered chair. The percentage of (Z) enolates also increases when ... This reactivity is widely applied in the industrial syntheses of pharmaceutical compounds. An example is the Merck and Dupont ... doi:10.1016/S0040-4039(00)99279-7. Carey, Francis A. (2007). "Organometallic compounds of Group I and II metals". Advanced ...
doi:10.1021/ja001511o) Crabtree, R. H. The Organometallic Chemistry of the Transition Metals, 5th ed.; Wiley: New York, 2009. ... Furthermore, the X group can dissociate at any time during the mechanism and bind to the Sn+ complex at the end. Density ... First, when the organostannane initially adds to the trans metal complex, the X group can coordinate to the tin, in addition to ... The most common side reactivity associated with the Stille reaction is homocoupling of the stannane reagents to form an R2-R2 ...
Redox reactions involving transition metals can also be used to produce aromatic systems which then serve as ligands in ... Alkyne trimerization is one simple case whereby the [2+2+2] cycloaddition of three alkynes yields a substituted benzene - ... Historic interest in benzene arose from the uncertainty over its structure and reactivity. It was well established that it had ... It is formed readily by direct reaction with potassium metal and uranocene, an analogue of ferrocene, has been prepared from ...
Louie's research aims to mediate these transitions via metal catalyzed reactions, mainly involving nickel catalysis. Dr. Louie ... "N-Heterocyclic Carbene Bound Nickel(I) Complexes and Their Roles in Catalysis." Organometallics 30.9 (2011): 2546-552. Web. [9] ... R. M. Stolley, H. A. Duong, J. Louie "Mechanistic Evaluation of the Ni(IPr)2-Catalyzed Cycloaddition of Alkynes and Nitriles to ... 2015, 48, 2534-2365; Invited Contribution to a Special Issue (Earth Abundant Metals in Homogeneous Catalysis). ● Y. Zhong, N. A ...
Like other transition metals, zirconium forms a wide range of inorganic compounds and coordination complexes. In general, these ... Most Zr metal is produced by the reduction of the zirconium(IV) chloride with magnesium metal in the Kroll process. The ... Zirconium binds urea, a property that has been utilized extensively to the benefit of patients with chronic kidney disease. For ... The high reactivity of zirconium with oxygen at high temperatures is exploited in some specialised applications such as ...
Carbon dioxide binds to metals in only a few ways. The bonding mode depends on the electrophilicity and basicity of the metal ... Illustrative structures of transition metal carbon dioxide complexes, from the left: Ni(η2-CO2)(PCy3)2, Rh(η1-CO2)ClL4 (L4 = ( ... Phenanthroline)Cu(PR3)] catalyst effect C-H carboxylation on terminal alkynes together with Cs2CO3[7] NHC-Cu-H species to ... Aresta, Michele; Gobetto, Roberto; Quaranta, Eugenio; Tommasi, Immacolata (October 1992). "A bonding-reactivity relationship ...
With transition metal alkyls, these oxides behave as electrophiles and insert into the bond between metals and their relatively ... Subsequent to the migration, the metal binds free CO (see figure below). CO insertion does not always involve migration. ... increasing the reactivity of insertion reactions. Oxidation state - Oxidation of the metal tends to increase insertion reaction ... The neutral ligand can be CO, alkene, alkyne, or in some cases, even carbene. Diverse reactions apply to the migratory ...
The orthogonal reactivity of the two metals shows high selectivity and extreme functional group tolerance in Sonogashira ... Here, FeCl3 is proposed to act as the transition-metal catalyst and Cs2CO3 as the base, thus theoretically proceeding through a ... It is suggested that the presence of base results in the formation of a pi-alkyne complex, complex E, which makes the terminal ... nicotine binding and psychotropic potency". Drug Development Research. 45 (1): 10-16. doi:10.1002/(SICI)1098-2299(199809)45:1. ...
These transition metal carbene complexes fall into two categories: Fischer carbenes in which carbenes are tethered to a metal ... from alkali metals, main group elements, transition metals and even lanthanides and actinides. A periodic table of elements ... Lithium ions may be chemically removed by binding to species such as cryptands or crown ethers. Metal free carbenes have been ... They exhibit both carbenic and alkynic reactivity. An X-ray structure of this molecule has not been obtained and at the time of ...
Crabtree, Robert H. (2009). The Organometallic Chemistry of the Transition Metals (5th ed.). Wiley. pp. 99-100. ISBN 978-0-470- ... Due to the chelate effect, ligands with two phosphine groups bind more tightly to metal centers than do two monodentate ... Reactivity[edit]. Phosphine ligands are usually "spectator" rather than "actor" ligands. They generally do not participate in ... which included reactions of alkynes, carbon monoxide, and alcohols.[12] In his studies, Reppe discovered that this reaction ...
Periana, for example, reported that complexes containing late transition metals, such as Pt, Pd, Au, and Hg, react with methane ... Kuhl, N.; Hopkinson, M. N.; Wencel-Delord, J.; Glorius, F. (2012). "Beyond Directing Groups: Transition Metal-Catalyzed C H ... The innate reactivity of the indole and enolate leads to the formation of the C-C bond to form the indole-carvone intermediate ... The pathway was proposed to involve binding of methane to Pt(II). In 1972, the Shilov group was able to produce methanol and ...
... transition metal - elements that have incomplete d sub-shells, but also may be referred to as the d-block elements transuranic ... the metals of Group 2 on the periodic table alkane - alkene - alkyl group - alkyne - allomer - a substance that has different ... reactivity series - reagent - redox - reducing agent - reduction potential - s-block elements - Group 1 and 2 elements (alkali ... a compound with two acyl groups bound to a single oxygen atom acid dissociation constant - an equilibrium constant for the ...
As with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. Copper does not react with ... This complex exhibits the fastest water exchange rate (speed of water ligands attaching and detaching) for any transition metal ... Cytochrome c oxidase is the protein that binds the O2 between a copper and an iron; the protein transfers 8 electrons to the O2 ... Conjugate addition to enones and carbocupration of alkynes can also be achieved with organocopper compounds. Copper(I) forms a ...
The theoretical and computational description of this zinc binding in proteins (as well as that of other transition metals) is ... "Transition Metal Elements" (PDF). Archived (PDF) from the original on October 10, 2014. Retrieved October 14, 2014. Habib, ... The relative reactivity of zinc and its ability to attract oxidation to itself makes it an efficient sacrificial anode in ... arenes and alkynes. The catalysts are nickel and palladium. A key step in the catalytic cycle is a transmetalation in which a ...
Several transition metal difluorides, such as those of copper(II) and nickel(II), are soluble. The alkaline earth metals form ... The reactivity of such species varies greatly-sulfur hexafluoride is inert, while chlorine trifluoride is extremely reactive- ... Bihary, Z.; Chaban, G. M.; Gerber, R. B. (2002). "Stability of a Chemically Bound Helium Compound in High-pressure Solid Helium ... However, if a perfluorocarbon contains double or triple bonds (perfluoroalkenes or -alkynes), a very reactive towards ligand ...
Alkali metal Alkaline earth metal Lan-thanide Actinide Transition metal Post-​transition metal Metalloid Reactive nonmetal ... Most of the chlorides of the pre-transition metals (groups 1, 2, and 3, along with the lanthanides and actinides in the +2 and ... Because of its great reactivity, all chlorine in the Earth's crust is in the form of ionic chloride compounds, which includes ... Chlorine adds to the multiple bonds on alkenes and alkynes as well, giving di- or tetra-chloro compounds. However, due to the ...
Many reactions of ethylene are catalyzed by transition metals, which bind transiently to the ethylene using both the π and π* ... ionic metal hydride. Beryllium hydride. Left (gas phase): BeH2. covalent metal hydride. Right: (BeH2)n (solid phase). polymeric ... The π-bond in the ethylene molecule is responsible for its useful reactivity. The double bond is a region of high electron ... Linear alkynes. *C2H2. *C3H4. *C4H6 ... This hydrocarbon has four hydrogen atoms bound to a pair of ...
The study of main-group molecules that behave and react similarly to transition-metal (TM) complexes has attracted significant ... As we discuss, this character is powerfully demonstrated by the reactivity of boron-based molecules with H2, CO, alkynes, ... Most notably, the attractive idea of replacing the all-too-often rare and costly metals from catalysis has motivated efforts to ... flexibility of TM complexes that arises from combinations of empty and filled d orbitals and that seem ideally suited to bind ...
Transition metal carbyne complexes are most common for the early transition metals, especially niobium, tantalum, molybdenum, ... Metal alkylidyne complexes have mainly been used for specialized reactions in the laboratory, the main used being alkyne ... Many cluster-bound carbyne complexes are known, typically with CO ligands. These compounds do not feature MC triple bonds; ... In a Fischer carbyne the C-carbyne exhibits electrophilic behavior while Schrock carbynes display nucleophilic reactivity on ...
Vanadium is an inexpensive common metal that could replace some of the precious metals currently found in catalysts used in ... While early- and mid-first row transition metals (e.g. Sc, Ti, V, Cr, Mn) have been largely studied for their role as promoter ... The vanadium catalyst exhibits unprecedented reactivity in liquid- and gas- phase alkene/alkyne hydrogenation. Catalyst ... Our group recently developed a series of well-defined, site- isolated first-row organo-transition metal catalysts (V3+, Cr3+, ...
Two is added for every lone pair bonding to the metal (e.g. each phosphine ligand can bind with a lone pair). Similarly Lewis ... One counts valence electrons for main group elements differently from transition metals. E.g. in period 2: B, C, N, O, and F ... each Lewis base binds with a lone pair). Unsaturated hydrocarbons such as alkenes and alkynes are considered Lewis bases. ... electron counting is an important tool for identifying the reactivity of molecules. Two methods of electron counting are ...
Organometallic Dinuclear Complexes of Transition Metals.Alkyl Transfer from Platinum,Palladium and Gold to Transition Metals ... Publications] K.Onitsuka: Synthesis and Properties of Ferrocenylethynyl Transition Metal Complex of Platinum,Palladium and ... Publications] T.Sone: Synthesis,Structure and Reactivities of cis-Dimethyl(ηl-allyl)gold(III)Complexes. Bull.Chem.Jpn. (in ... Publications] K.Nozaki: A Chiral Bimetallic Lewis Acid:A Cooperative Binding of Two Amine Molecules to a Chiral Diboronic ...
EAN rule, Synthesis structure and reactivity of metal carbonyls; carboxylate anions, carbonyl hydrides and metal nitrosyl ... First row transition metals and general properties of their compounds (oxides, halides and sulphides); lanthanide contraction. ... Complexes with aromatic systems, synthesis, structure and bonding in metal olefin complexes, alkyne complexes and ... 1.8 Nuclear Chemistry : Nuclear reactions; mass defect and binding energy, nuclear fission and fusion. Nuclear reactors; ...
... the transition metal complex in a lower oxidation state (Mtn/Lm, where Mt is the metal and L is the ligand) is directly added ... The reactivity of these glycopolymers in the presence of model lectins able to selectively bind mannose (Con A) and galactose ( ... Various transition metals can be employed in ATRP (Cu, Ru, Fe, Ni, etc.). In the first ATRP process, called direct ATRP, ... Alkyne-terminated PNIPAAm (Mn = 2 kDa, Mw/Mn , 1.2) obtained from RAFT was successfully coupled via CuAAC to MUC1 VNTR peptide ...
ReactivityEdit. Main article: Reactivity (chemistry). The reactivities of the alkali metals increase going down the group. This ... The group 11 metals (or coinage metals), copper, silver, and gold, are typically categorised as transition metals given they ... The alkali metal peroxides are ionic compounds that are unstable in water. The peroxide anion is weakly bound to the cation, ... The alkali metals and their hydrides react with acidic hydrocarbons, for example cyclopentadienes and terminal alkynes, to give ...
Add two for every lone pair bonding to the metal (e.g. each Lewis base binds with a lone pair). Unsaturated hydrocarbons such ... Polyhedral skeletal electron pair theory for cluster compounds, including transition metals and main group elements such as ... electron counting is an important tool for identifying the reactivity of molecules. ... as alkenes and alkynes are considered Lewis bases. Similarly Lewis and Bronsted acids (protons) contribute nothing. ...
Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn. ... dipolar cycloaddition using resin-bound alkynes or alkenes. Tetrahedron Letters, 53 2096-2099. DOI: 10.1016/j.tetlet.2012.02. ... Isoxazoline zinc amidase inhibitors bearing diverse metal binding groups. Journal of Medicinal Chemistry, 45 4359-4370. DOI: ... DFT study predicts unprecedented reactivity and intermediates. Journal of the American Chemical Society, 127 210-216. DOI: ...
In addition, alkanes have been shown to interact with, and bind to, certain transition metal complexes in (See: carbon-hydrogen ... and alkyne lowest alkyne nonpolarnya is because among the three compounds on the most easily soluble in water is alkyne and ... Generally, nonmetals have more positive Eea than metals. Atoms whose anions are more stable than neutral atoms have a greater ... In general, alkanes show a relatively low reactivity, because their C bonds are relatively stable and cannot be easily broken. ...
A metal catalyzed click chemistry ligation process is employed to bind azides and terminal acetylenes to give triazoles. In ... Therefore, in order to have a useful reactivity window, one should choose or design such ligands that do bind to the metal ... For a review of reactions of L-ascorbic acid with transition metals see M. B. Davies Polyhedron 1992, 11, 285-321 and ... The reaction proceeded well in fresh human plasma (protein loading 65-85 mg/mL, Cazide=Calkyne=5 mM; CCu+=100 mM) and in whole ...
metal complexes mechanism hydrogenation reactivity spectroscopy parahydrogen alkenes alkynes nitriles two-electron redox ... However, due to the inherent electronic structure of these metals, common first-row transition metal complexes have a ... a nonclassical binding mode of H2 was established, (MesCCC)Co(H2)(PPh3). The scrambling of H2 and D2 by the Co(I)-(H2) species ... The widespread use of homogenous late second- and third-row transition metal complexes for the catalytic hydrogenation of ...
20-25 capping by transition-metal organometallic fragments,26-34 insertion of a transition-metal atom at the center of the ... and a gas-phase proton-bound anionic cluster of peptide-reference acid is formed. The proton-bound cluster is mass isolated and ... Collectively, the three instruments provide complementary information about the chemical composition, reactivity and structure ... 48-50 and functionalization with various organic residues by reactions with organic halides and alkynes.51-58 This latter ...
First row transition metals and general properties of their compounds (oxides, halides and sulphides); lanthanide contraction. ... Metal forming processes and machines-shearing, drawing, spinning, rolling, forging, extrusion. Types of casting and welding ... Binding energy of nuclei, nuclear fission and fusion. Classification of elementary particles and their ... Chemical reactivity of noble gases, preparation, structure and bonding of noble gas ...
Carbon dioxide utilization : from fundamental reactivity to catalysis using transition metals supported by macrocyclic ... Molybdate, a molecular metal oxide, readily binds CO₂ at room temperature to produce a robust monocarbonate complex, [MoO₃(k²- ... and alkynes (Chapter 1). Gold(I) and fluoride add trans across the triple bond of 3-hexyne and ... ... Cathodic electrodeposition of metal-organic frameworks  Li, Minyuan Miller (Massachusetts Institute of Technology, 2015) ...
Transition metal-mediated donor-acceptor coordination of low-oxidation state Group 14 element halides. Anindya K. Swarnakar, ... Binding small molecules and ions to [Fe4S4Cl4]2− modulates rate of protonation of the cluster. Thaer M. M. Al-Rammahia and ... Comparing the reactivities of this dimer with the two monomers that feature different simple chelating phosphine ligands, they ... The carboboration of Me3Si-substituted alkynes and allenes with boranes and borocations. James R. Lawson, Valerio Fasano, ...
Many metal-containing compounds, especially those of transition metals, are coordination complexes.[4] A coordination complex ... the ions would bind via the ammonia chains Blomstrand had described or the ions would bind directly to the metal. ... Complexes show a variety of possible reactivities:[22]. *Electron transfers Electron transfer (ET) between metal ions can occur ... Organometallic Chemistry: Ligands are organic (alkenes, alkynes, alkyls) as well as "organic-like" ligands such as phosphines, ...
In certain transition metal-arene complexes, such as ferrocenes, the transition metal attracts electron-density from the arene ... and the transition state is not as tightly bound as a six-membered chair. The percentage of (Z) enolates also increases when ... This reactivity is widely applied in the industrial syntheses of pharmaceutical compounds. An example is the Merck and Dupont ... doi:10.1016/S0040-4039(00)99279-7. Carey, Francis A. (2007). "Organometallic compounds of Group I and II metals". Advanced ...
Hein JE, Fokin VV (2010) Copper-catalyzed azide-alkyne cycloaddition (CuAAC) and beyond: new reactivity of copper(I) acetylides ... Meanwhile, other transition metals such as ruthenium, rhodium and silver are now under development as alternative sources for ... A global map of lipid-binding proteins and their ligandability in cells. Cell 161:1668-1680CrossRefGoogle Scholar ... Bioorthogonal reaction Transition metal Cycloaddition reaction CuAAC reaction Unnatural amino acids Maiyun Yang and Yi Yang ...
Achiral and chiral transition metal complexes with modularly designed tridentate PNP pincer-type ligands based on N- ... 1. Synthesis and Reactivity of Ru(HB(pz)3)(COD)X (X = Cl, Br) and Ru(HB(pz)3)(L2)Cl (L = Nitrogen and …. C Gemel, G Trimmel, C ... Mechanism for the cyclotrimerization of alkynes and related reactions catalyzed by CpRuCl. K Kirchner, MJ Calhorda, R Schmid, ... Stereospecific and reversible CO binding at iron pincer complexes. D Benito‐Garagorri, M Puchberger, K Mereiter, K Kirchner ...
Dissolution of surface-bound H-atoms. To investigate the dissolution of surface-bound H-atoms in the metal, the activation ... The interaction of hydrogen with transition metals has been extensively studied by both experimental and theoretical methods ... in the active Ni metal phase that has a crucial role in the hydrogenation of alkenes and alkynes. However, a microscopic ... The formation rate of H-atoms largely depends on either the reactivity of the surface site to dissociation of H2 in a thermal ...
Comparable carbonyl metal compounds are not yet known. Table 1. Metal isocyanide complexes of 3d transition metals Like CO, ... The question thus raised regarding the mechanism of the conversion of 1-alkynes to metal-bound vinylidenes could at first be ... form very stable complexes with transition metals. This article documents the family relationships by structure and reactivity ... 78i the possible threefold bridging seems particularly likely when M is a transition metal and M an electropositive metal such ...
... using neutral or anionic complexes of transition metals. ... and typically bind to transition metals via electron pair ... solubility or reactivity of the resulting metal complex, or any combination of these factors. Both aryl and heteroaryl ... alkynes, halogens, ethers, thioethers, amides, esters, acids, and nitrogen containing groups. In one embodiment, the ligand ... a metal ion may bind six monodentate ligands, three bidentate ligands, or two tridentate ligands. The metal ion may even bind a ...
First row transition metals and general properties of their compounds (oxides, halides and sulphides); lanthanide contraction. ... d) Complexes with aromatic systems, synthesis, structure and bonding in metal olefin complexes, alkyne complexes and ... Chemical reactivity of noble gases, preparation, structure and bonding of noble gas compounds.. (iii) Chemistry of d block ... 1.8 Nuclear Chemistry : Nuclear reactions; mass defect and binding energy, nuclear fission and fusion. Nuclear reactors; ...
  • As we discuss, this character is powerfully demonstrated by the reactivity of boron-based molecules with H2, CO, alkynes, alkenes and even with N2. (uni-wuerzburg.de)
  • Last, the vanadium atoms had to be "low-coordinated", which means that there would be electronic room for the target molecules to bind. (greencarcongress.com)
  • Hydrides can be components of discrete molecules , oligomers or polymers , ionic solids , chemisorped monolayers, bulk metals, and other materials. (thefullwiki.org)
  • New organometallic chemosensors which are based on triad molecules, ferrocenyl naphthoquinone linearly/angularly fused crown ethers (Fc-cnq-1a and Fc-cnq-1b) bearing ferrocene, quinone, and crown ether functional groups together, were synthesized and utilized for selective sensing trace amount of Be2+ ion (5.41 mu M) among other metal cations. (benran.ru)
  • Building on preliminary results showing that a C=O bond can function as a hemilabile ligand in a catalytic cycle, I will undertake a systematic, experimental and theoretical investigation of the structure and reactivity of M-C-E three membered rings formed by side-on coordination of C=E bonds to a first-row metal. (europa.eu)
  • They are also called metal alkylidynes-the carbon is a carbyne ligand. (wikipedia.org)
  • Also, the higher the energy of the d-orbitals belonging to an electron-rich metal center the higher the energy of the metal-carbon π-bonds. (wikipedia.org)
  • Here, we review recent studies that examine the chemical activity of metal carbide and phosphides as a function of size, from clusters to extended surfaces, and metal/carbon or metal/phosphorous ratio. (unt.edu)
  • In these studies, X-ray crystallographic analysis showed that for carbonyl-stabilised ylides, σ -coordination through the ylide carbon-atom was the preferred mode of bonding, rather than the alternative oxygen-bound possibility. (springer.com)
  • C08F4/65908 - Component covered by group C08F4/64 containing a transition metal-carbon bond in combination with an ionising compound other than alumoxane, e.g. (google.com)
  • The HOMO of the carbyne ligand interacts with the LUMO of the metal to create the σ-bond. (wikipedia.org)
  • One is added for every halide or other anionic ligand which binds to the central atom through a sigma bond. (wikipedia.org)
  • This method begins by calculating the number of electrons of the element, assuming an oxidation state E.g. for a Fe2+ has 6 electrons S2− has 8 electrons Two is added for every halide or other anionic ligand which binds to the metal through a sigma bond. (wikipedia.org)
  • Two is added for every lone pair bonding to the metal (e.g. each phosphine ligand can bind with a lone pair). (wikipedia.org)
  • Comparisons of the carboxylate 13C signal enhancement of ethyl propionate using [(dppb)Rh(COD)]BF4 and (MesCCC)Co-py, showed that the cobalt complex hyperpolarization efficiency is comparable with the rhodium system, demonstrating that the monoanionic bis(carbene) pincer ligand supports noble-metal reactivity with cobalt. (illinois.edu)
  • Importantly, the analysis was first conducted without any preset metal-ligand bonds, to assure a reliable structure determination in an unbiased manner. (jove.com)
  • The atom within a ligand that is bonded to the central metal atom or ion is called the donor atom . (wikipedia.org)
  • Our tridentate ancillary ligand (PNP) incorporates both the "hard" amide donor and the "soft" phosphine ligand to generate a unique environment capable of binding to most elements in the periodic table. (ubc.ca)
  • Furthermore, complexation as a ligand with an Rh-I ion afforded a unique binding mode and retained the Mobius aromaticity. (benran.ru)
  • Ligand binding (Biochemistry). (dartmouth.edu)
  • Metal-organic frameworks (MOFs) represent a class of functional coordination polymers with long-range order, great synthetic flexibility, and exceptionally high internal surface area. (mit.edu)
  • carbonylmetal clusters have achieved a degree of importance undreamed of twenty years ago, in particular as cage frameworks for both smaller and larger metal and nonmetal atoms. (docme.ru)
  • These results comprise an unprecedented example of a metal complex that is capable of facile N-H bond activation in such a wide range of substrates, including challenging substrates such as ammonia and alkyl amines. (oatd.org)
  • The electrophilic C=E multiple bond is designed to act as an acceptor moiety that adapts its binding mode to the electronic structure of reactive intermediates with the unique additional possibility of involving the lone pairs on heteroelement E in cooperative reactivity. (europa.eu)
  • Additionally, these two carbenes only differ in their electrophilic character and not their steric parameters, making them ideal for studying how carbene electronics influence reactivity. (jove.com)
  • When the addition reactions of electrophilic reagents, such as strong Brønsted acids and halogens, to alkynes are studied we find a curious paradox. (msu.edu)
  • Although these electrophilic additions to alkynes are sluggish, they do take place and generally display Markovnikov Rule regioselectivity and anti-stereoselectivity. (msu.edu)
  • Generally when a transition metal carbyne complex undergoes photooxidation a new organic ring structure is formed. (wikipedia.org)
  • 1. A Cu(I) catalyzed process for preparing a 1,4-disubstituted 1,2,3-triazole comprising: contacting an organic azide and a terminal alkyne with a catalytic quantity of Cu(I) ion for a time sufficient to form by cycloaddition a 1,4-disubstituted 1,2,3-triazole. (freepatentsonline.com)
  • Some metal hydrides behave as hydrogen-atom donors and as acids. (thefullwiki.org)
  • Hydrides are already of vast importance in storage battery technologies such as Nickel-metal hydride battery . (thefullwiki.org)
  • Various metal hydrides are currently being studied for use as a means of hydrogen storage for fuel cell -powered electric cars and other purposed aspects of a hydrogen economy . (thefullwiki.org)
  • In this paper a unified view of coherent and incoherent dihydrogen exchange in transition metal hydrides by nuclear magnetic resonance (NMR) and inelastic neutron scattering (INS) is presented. (unt.edu)
  • The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), [note rubidium (Rb), caesium (Cs), [note and francium (Fr). (wikipedia.org)
  • [note Indeed, the alkali metals provide the best example of group trends in properties in the periodic table, with elements exhibiting well-characterised homologous behaviour. (wikipedia.org)
  • The alkali metals are all shiny, soft , highly reactive metals at standard temperature and pressure and readily lose their outermost electron to form cations with charge +1. (wikipedia.org)
  • All the alkali metals react with water, with the heavier alkali metals reacting more vigorously than the lighter ones. (wikipedia.org)
  • Most alkali metals have many different applications. (wikipedia.org)
  • Sodium and potassium are also essential elements , having major biological roles as electrolytes , and although the other alkali metals are not essential, they also have various effects on the body, both beneficial and harmful. (wikipedia.org)
  • In a typical complex, a metal ion is bonded to several donor atoms, which can be the same or different. (wikipedia.org)
  • In some cases an atom or a group offers a pair of electrons to two similar or different central metal atoms or acceptors-by division of the electron pair-into a three-center two-electron bond . (wikipedia.org)
  • 5 0 i .2510 1077 ecule to one or several metal atoms can be either end-on or via p2 or p3 bridges (Fig. 2). (docme.ru)
  • When a threshold H-coverage is passed, corresponding to 1.00 ML for the crystalline Ni(111) surface, the surface-bound H-atoms start to diffuse to the subsurface. (rsc.org)
  • 5-7 Here, the H-kinetics of dissociative adsorption of H 2 or, equivalently, the associative desorption of H 2 , and the dissolution of surface-bound H-atoms are investigated for different H-coverages at the Ni(111) surface. (rsc.org)
  • This results in the reduction of surface-bound H-atoms and consequently the increase the rate of products rather than reactants. (rsc.org)
  • 14. Solid inorganic polymer derived from organo group-containing phosphorous or phosphoric acids, in which the organo group is selected from the group consisting of alicyclics, aromatics and heterocyclics wherein, three oxygens bonded tophosphorus are structurally linked to one or more tetravalent zirconium atoms, and wherein the molar ratio of phosphorus to zirconium metal is about 2 to 1. (patentgenius.com)
  • The two π-bonds are formed when the two HOMO orbitals of the metal back-donate to the LUMO of the carbyne. (wikipedia.org)
  • The M-C distances are typically shorter than the M-C bonds found in metal carbenes. (wikipedia.org)
  • A solution of the mixture of the peptide and a reference acid is introduced into the mass spectrometer, and a gas-phase proton-bound anionic cluster of peptide-reference acid is formed. (jove.com)
  • even if it does turn out to be an alkali metal, it is predicted to have some differences in physical and chemical properties from its lighter homologues. (wikipedia.org)
  • 4. A method, as claimed in claim 1 , wherein in the staining mixture at least one metal ion is a ruthenium, an osmium, a rhenium, or a platinum ion. (google.com)
  • High-temperature thermolysis also can result in complete cleavage of the alcohol arm, eliminating tert-butyloxirane and forming the B-N bound imidazolium borate 7. (jove.com)
  • The molecular basis of protein partner selection and DNA binding of the basic helix loop helix (bHLH) and basic region-leucine zipper (bZIP) superfamilies of dimeric transcription factors is fundamental toward understanding gene regulation. (utoronto.ca)