Datasets:

BASF-AI

/

WikipediaEasy2SpecialClassification

like 0

Follow

BASF 23

Carboxylation is a chemical reaction in which a carboxylic acid is produced by treating a substrate with carbon dioxide. The opposite reaction is decarboxylation. In chemistry, the term carbonation is sometimes used synonymously with carboxylation, especially when applied to the reaction of carbanionic reagents with CO. More generally, carbonation usually describes the production of carbonates.

Organic Reactions

The Büchner–Curtius–Schlotterbeck reaction can be used to facilitate one carbon ring expansions when the substrate ketone is cyclic. For instance, the reaction of cyclopentanone with diazomethane forms cyclohexanone (shown below). The Büchner ring expansion reactions utilizing diazoalkanes have proven to be synthetically useful as they can not only be used to form 5- and 6-membered rings, but also more unstable 7- and 8-membered rings. An acyl-diazomethane can react with an aldehyde to form a β-diketone in the presence of a transition metal catalyst (SnCl in the example shown below). β-Diketones are common biological products, and as such, their synthesis is relevant to biochemical research. Furthermore, the acidic β-hydrogens of β-diketones are useful for broader synthetic purposes, as they can be removed by common bases. Acyl-diazomethane can also add to esters to form β-keto esters, which are important for fatty acid synthesis. As mentioned above, the acidic β-hydrogens also have productive functionality. The Büchner–Curtius–Schlotterbeck reaction can also be used to insert a methylene bridge between a carbonyl carbon and a halogen of an acyl halide. This reaction allows conservation of the carbonyl and halide functionalities. It is possible to isolate nitrogen-containing compounds using the Büchner–Curtius–Schlotterbeck reaction. For example, an acyl-diazomethane can react with an aldehyde in the presence of a DBU catalyst to form isolable α-diazo-β-hydroxy esters (shown below).

Organic Reactions

The asymmetric Darzens reaction between aldehydes and (alpha)-haloesters is an effective method for the synthesis of glycidic esters. Chiral auxiliaries, chiral boron enolates, and asymmetric phase transfer catalysis have been used successfully to effect asymmetric induction in the Darzens reaction. Diastereoselective epoxidations of chiral, non-racemic alkenes suffer from the limitation that removal of the auxiliary without disturbing the epoxide is often difficult. Nonetheless, diastereoselectivity is high in some cases. Oxidation of epoxy alcohols generated via Sharpless epoxidation is a third method for the enantioselective synthesis of chiral α,β-epoxy carbonyl compounds. Swern and Parikh-Doering conditions are most commonly applied to accomplish these oxidations.

Organic Reactions

Barium nitrite is a chemical compound, the nitrous acid salt of barium. It has the chemical formula Ba(NO). It is a water-soluble yellow powder. It is used to prepare other metal nitrites, such as lithium nitrite. __TOC__

Inorganic Reactions + Inorganic Compounds

HCN is obtainable from fruits that have a pit, such as cherries, apricots, apples, and bitter almonds, from which almond oil and flavoring are made. Many of these pits contain small amounts of cyanohydrins such as mandelonitrile and amygdalin, which slowly release hydrogen cyanide. One hundred grams of crushed apple seeds can yield about 70 mg of HCN. So-called "bitter" roots of the cassava plant may contain up to 1 gram of HCN per kilogram. Some millipedes, such as Harpaphe haydeniana, Desmoxytes purpurosea, and Apheloria release hydrogen cyanide as a defense mechanism, as do certain insects, such as burnet moths and the larvae of Paropsisterna eucalyptus. Hydrogen cyanide is contained in the exhaust of vehicles, and in smoke from burning nitrogen-containing plastics.

Inorganic Reactions + Inorganic Compounds

The decreasing electronegativity with increasingly heavy chalcogenides leads to a reversal of the dipole. In NO, oxygen is the more electronegative element. In NS, nitrogen is more electronegative. The NS radical is significantly more unstable and prone to catenation than NO.

Inorganic Reactions + Inorganic Compounds

Hydrolysis of xenon hexafluoride or xenon tetrafluoride yields a solution from which colorless XeO crystals can be obtained by evaporation. The crystals are stable for days in dry air, but readily absorb water from humid air to form a concentrated solution. The crystal structure is orthorhombic with a = 6.163 Å, b = 8.115 Å, c = 5.234 Å, and 4 molecules per unit cell. The density is 4.55 g/cm.

Inorganic Reactions + Inorganic Compounds

The intramolecular Heck reaction may be used to form rings of a variety of sizes and topologies. β-Hydride elimination need not be the final step of the reaction, and tandem methods have been developed that involve the interception of palladium alkyl intermediates formed after migratory insertion by an additional reactant. This section discusses the most common ring sizes formed by the intramolecular Heck reaction and some of its tandem and asymmetric variants. 5-Exo cyclization, which establishes a five-membered ring with an exocyclic alkene, is the most facile cyclization mode in intramolecular Heck reactions. In this and many other modes of intramolecular Heck cyclization, annulations typically produce a cis ring juncture. 6-Exo cyclization is also common. The high stability of Heck reaction catalysts permits the synthesis of highly strained compounds at elevated temperatures. In the example below, the arene and alkene must both be in energetically unfavorable axial positions in order to react. Endo cyclization is observed most often when small or large rings are involved. For instance, 5-endo cyclization is generally preferred over 4-exo cyclization. The yield of endo product increases with increasing ring size in the synthesis of cycloheptenes, -octenes, and -nonenes. Tandem reactions initiated by IMHR have been extensively explored. Palladium alkyl intermediates generated after migratory insertion may undergo a second round of insertion in the presence of a second alkene (either intra- or intermolecular). When dienes are involved in the intramolecular Heck reaction, insertion affords π-allylpalldium intermediates, which may be intercepted by nucleophiles. This idea was applied to a synthesis of (–)-morphine. Asymmetric IMHR may establish tertiary or quaternary stereocenters. BINAP is the most commonly chiral ligand used in this context. An interesting application of IMHR is group-selective desymmetrization (enantiotopic group selection), in which the chiral palladium aryl intermediate undergoes insertion predominantly with one of the enantiotopic double bonds.

Organic Reactions

Two-metal dual activation represents the combination of the enolate activation mode and the alkyne activation mode into a single reaction system. Generally, a hard, oxophilic metal (K, Na, Ag) activates the enolate oxygen, while a soft, carbophilic metal (Pd, Cu, Mo) coordinates with the alkyne. In some instances, however, the precise role of each metal is unclear. For example, in a 2005 study Toste et al. found that treatment of an alkynyl-tethered β-ketoester with a Pd(II) phosphine complex and Yb(OTf) effected asymmetric cyclization to the corresponding cyclopentane. It is proposed that a Pd-enolate adds into a Yb-activated alkyne, though there is also precedent for Pd activation of alkynes.

Organic Reactions

Strontium bromate is a rarely considered chemical in the laboratory or in industries. It is, however, mentioned in the book Uncle Tungsten: Memories of a Chemical Boyhood by Oliver Sacks. There it is said that this salt glows when crystallized from a saturated aqueous solution. Chemically this salt is soluble in water, and is a moderately strong oxidizing agent. Strontium bromate is toxic if ingested and irritates the skin and respiratory tract if come into contact with or inhaled, respectively. Its chemical formula is Sr(BrO).

Inorganic Reactions + Inorganic Compounds

is built up of double layers of hydroxyl groups with aluminium ions occupying two-thirds of the octahedral holes between the two layers. Four polymorphs are recognized. All feature layers of octahedral aluminium hydroxide units, with hydrogen bonds between the layers. The polymorphs differ in terms of the stacking of the layers. All forms of crystals are hexagonal : * gibbsite is also known as γ- or α- * bayerite is also known as α- or β-alumina trihydrate * nordstrandite is also known as * doyleite Hydrargillite, once thought to be aluminium hydroxide, is an aluminium phosphate. Nonetheless, both gibbsite and hydrargillite refer to the same polymorphism of aluminium hydroxide, with gibbsite used most commonly in the United States and hydrargillite used more often in Europe. Hydrargillite is named after the Greek words for water () and clay ().

Inorganic Reactions + Inorganic Compounds

One of the methods of synthesis is the reaction of direct neutralization of oxalic acid with lithium hydroxide:

Inorganic Reactions + Inorganic Compounds

The redox mechanism involves a change in the oxidation state of the catalytic material. In this mechanism, CO is oxidized by an O-atom intrinsically belonging to the catalytic material to form CO. A water molecule undergoes dissociative adsorption at the newly formed O-vacancy to yield two hydroxyls. The hydroxyls disproportionate to yield H and return the catalytic surface back to its pre-reaction state.

Inorganic Reactions + Inorganic Compounds

A detailed mechanism for the Murai reaction has not been elucidated. Experimental and computational studies give evidence for at least two different mechanisms, depending on the catalyst. For catalysts such as [Ru(H)(CO)(PR)] which are active as Ru, a combination of computational density functional studies and experimental evidence has resulted in the following proposed mechanism: It is proposed that at high temperatures RuH(CO)(PPh) converts to an unsaturated Ru(CO)(PPh) species. The catalytic cycle is proposed to begins with coordination of the ketone followed by oxidative addition of a C-H bond. The resulting five-coordinated metallocycle is stabilized by an agostic interaction. The C-C bond formation is the rate limiting step.

Organic Reactions

Sodium aluminosilicate refers to compounds which contain sodium, aluminium, silicon and oxygen, and which may also contain water. These include synthetic amorphous sodium aluminosilicate, a few naturally occurring minerals and synthetic zeolites. Synthetic amorphous sodium aluminosilicate is widely used as a food additive, E 554.

Inorganic Reactions + Inorganic Compounds

Sodium molybdate, NaMoO, is useful as a source of molybdenum. This white, crystalline salt is often encountered as the dihydrate, NaMoO·2HO.

Inorganic Reactions + Inorganic Compounds

Reaction of soluble lanthanum nitrate with an excess of oxalic acid: Also, a reaction of lanthanum chloride with oxalic acid:

Inorganic Reactions + Inorganic Compounds

Barium azide can be used to make azides of magnesium, sodium, potassium, lithium, rubidium and zinc with their respective sulfates. It can also be used as a source for high purity nitrogen by heating: This reaction liberates metallic barium, which is used as a getter in vacuum applications.

Inorganic Reactions + Inorganic Compounds

Generally this topic is discussed when covering tandem mass spectrometry fragmentation and occurs generally by the same mechanisms. For example, of a mechanism of alpha-cleavage, an electron is knocked off an atom (usually by electron collision) to form a radical cation. Electron removal generally happens in the following order: 1) lone pair electrons, 2) pi bond electrons, 3) sigma bond electrons. One of the lone pair electrons moves down to form a pi bond with an electron from an adjacent (alpha) bond. The other electron from the bond moves to an adjacent atom (not one adjacent to the lone pair atom) creating a radical. This creates a double bond adjacent to the lone pair atom (oxygen is a good example) and breaks/cleaves the bond from which the two electrons were removed. In molecules containing carbonyl groups, alpha-cleavage often competes with McLafferty rearrangement.

Organic Reactions

In the Hunsdiecker reaction, carboxylic acids are converted to organic halide, whose carbon chain is shortened by one carbon atom with respect to the carbon chain of the particular carboxylic acid. The carboxylic acid is first converted to its silver salt, which is then oxidized with halogen: Many organometallic compounds react with halogens to give the organic halide:

Organic Reactions

Some authors have shown that neurons can produce hydrogen cyanide upon activation of their opioid receptors by endogenous or exogenous opioids. They have also shown that neuronal production of HCN activates NMDA receptors and plays a role in signal transduction between neuronal cells (neurotransmission). Moreover, increased endogenous neuronal HCN production under opioids was seemingly needed for adequate opioid analgesia, as analgesic action of opioids was attenuated by HCN scavengers. They considered endogenous HCN to be a neuromodulator. It has also been shown that, while stimulating muscarinic cholinergic receptors in cultured pheochromocytoma cells increases HCN production, in a living organism (in vivo) muscarinic cholinergic stimulation actually decreases HCN production. Leukocytes generate HCN during phagocytosis, and can kill bacteria, fungi, and other pathogens by generating several different toxic chemicals, one of which is hydrogen cyanide. The vasodilatation caused by sodium nitroprusside has been shown to be mediated not only by NO generation, but also by endogenous cyanide generation, which adds not only toxicity, but also some additional antihypertensive efficacy compared to nitroglycerine and other non-cyanogenic nitrates which do not cause blood cyanide levels to rise. HCN is a constituent of tobacco smoke.

Inorganic Reactions + Inorganic Compounds

The Hirao coupling (also called the Hirao reaction or the Hirao cross-coupling) is the chemical reaction involving the palladium-catalyzed cross-coupling of a dialkyl phosphite and an aryl halide to form a phosphonate. This reaction is named after Toshikazu Hirao and is related to the Michaelis-Arbuzov reaction. In contrast to the classic Michaelis-Arbuzov reaction, which is limited to alkyl phosphonates, the Hirao coupling can also deliver aryl phosphonates.

Organic Reactions

Hydrogen cyanide will react with alkenes under catalysis of nickel complexes. This reaction is called hydrocyanation. :RCH=CH + HCN → RCH-CH-CN Four molecules of HCN will tetramerize into diaminomaleonitrile, which can be converted to various purines.

Inorganic Reactions + Inorganic Compounds

Hexaammineplatinum(IV) chloride is the chemical compound with the formula [Pt(NH)]Cl. It is the chloride salt of the metal ammine complex [Pt(NH)]. The cation features six ammonia (called ammines in coordination chemistry) ligands attached to the platinum(IV) ion. It is a white, water soluble solid.

Inorganic Reactions + Inorganic Compounds

The active site of PLE facilitates both substrate binding and hydrolysis. A key serine residue in the active site promotes hydrolysis, but the substrate must present an ester group to this residue after binding to the enzyme active site for hydrolysis to take place. Whether the substrate is able to present an ester group to the catalytic serine residue depends on its bound conformation in the active site, which is dictated by amino acid side-chains in the active site. Thus, active site models of PLE have been advanced with the goal of predicting from the structure of the substrate which of two enantiotopic ester groups will be hydrolyzed (or whether hydrolysis is likely to occur at all). A simple model for the binding conformation of an ester in the active site of PLE is shown below. This model accurately predicts the configuration of hydrolyzed glutarates and similar substrates.

Organic Reactions

A mixture of bromo acetal 1 (549 mg, 1.78 mmol), AIBN (30.3 mg, 0.185 mmol), and BuSnH (0.65 mL, 2.42 mmol) in dry benzene (12 mL) was heated under reflux for 1 hour and then evaporated under reduced pressure. Silicagel column chromatography of the crude product with hexane–EtOAc (92:8) as eluant gave tetrahydropyran 2 (395 mg, 97%) as an oily mixture of two diastereomers. (c 0.43, CHCl); IR (CHCl):1732 cm–1;1H NMR (CDCl)δ 4.77–4.89 (m, 0.6H), 4.66–4.69 (m, 0.4H), 3.40–4.44 (m, 4H), 3.68 (s, 3H), 2.61 (dd, J = 15.2, 4.2 Hz, 1H), 2.51 (dd, J = 15.2, 3.8 Hz, 1H), 0.73–1.06 (m, 3H); mass spectrum: m/z 215 (M+–Me); Anal. Calcd for CHO: C, 62.6; H, 9.65. Found: C, 62.6; H, 9.7.

Organic Reactions

Aluminium hydroxide, , is found in nature as the mineral gibbsite (also known as hydrargillite) and its three much rarer polymorphs: bayerite, doyleite, and nordstrandite. Aluminium hydroxide is amphoteric, i.e., it has both basic and acidic properties. Closely related are aluminium oxide hydroxide, AlO(OH), and aluminium oxide or alumina (), the latter of which is also amphoteric. These compounds together are the major components of the aluminium ore bauxite. Aluminium hydroxide also forms a gelatinous precipitate in water.

Inorganic Reactions + Inorganic Compounds

Iodolactonization (or, more generally, halolactonization) is an organic reaction that forms a ring (the lactone) by the addition of an oxygen and iodine across a carbon-carbon double bond. It is an intramolecular variant of the halohydrin synthesis reaction. The reaction was first reported by M. J. Bougalt in 1904 and has since become one of the most effective ways to synthesize lactones. Strengths of the reaction include the mild conditions and incorporation of the versatile iodine atom into the product. Iodolactonization has been used in the synthesis of many natural products including those with medicinal applications such as vernolepin and vernomenin, two compounds used in tumor growth inhibition, and vibralactone, a pancreatic lipase inhibitor. Iodolactonization has also been used by Elias James Corey to synthesize numerous prostaglandins.

Organic Reactions

Amino acid N-carboxyanhydrides, also called Leuchs' anhydrides, are a family of heterocyclic organic compounds derived from amino acids. They are white, moisture-reactive solids. They have been evaluated for applications the field of biomaterials.

Organic Reactions

Some electronic properties of gallium arsenide are superior to those of silicon. It has a higher saturated electron velocity and higher electron mobility, allowing gallium arsenide transistors to function at frequencies in excess of 250 GHz. GaAs devices are relatively insensitive to overheating, owing to their wider energy band gap, and they also tend to create less noise (disturbance in an electrical signal) in electronic circuits than silicon devices, especially at high frequencies. This is a result of higher carrier mobilities and lower resistive device parasitics. These superior properties are compelling reasons to use GaAs circuitry in mobile phones, satellite communications, microwave point-to-point links and higher frequency radar systems. It is also used in the manufacture of Gunn diodes for the generation of microwaves. Another advantage of GaAs is that it has a direct band gap, which means that it can be used to absorb and emit light efficiently. Silicon has an indirect band gap and so is relatively poor at emitting light. As a wide direct band gap material with resulting resistance to radiation damage, GaAs is an excellent material for outer space electronics and optical windows in high power applications. Because of its wide band gap, pure GaAs is highly resistive. Combined with a high dielectric constant, this property makes GaAs a very good substrate for integrated circuits and unlike Si provides natural isolation between devices and circuits. This has made it an ideal material for monolithic microwave integrated circuits (MMICs), where active and essential passive components can readily be produced on a single slice of GaAs. One of the first GaAs microprocessors was developed in the early 1980s by the RCA Corporation and was considered for the Star Wars program of the United States Department of Defense. These processors were several times faster and several orders of magnitude more radiation resistant than their silicon counterparts, but were more expensive. Other GaAs processors were implemented by the supercomputer vendors Cray Computer Corporation, Convex, and Alliant in an attempt to stay ahead of the ever-improving CMOS microprocessor. Cray eventually built one GaAs-based machine in the early 1990s, the Cray-3, but the effort was not adequately capitalized, and the company filed for bankruptcy in 1995. Complex layered structures of gallium arsenide in combination with aluminium arsenide (AlAs) or the alloy AlGaAs can be grown using molecular-beam epitaxy (MBE) or using metalorganic vapor-phase epitaxy (MOVPE). Because GaAs and AlAs have almost the same lattice constant, the layers have very little induced strain, which allows them to be grown almost arbitrarily thick. This allows extremely high performance and high electron mobility HEMT transistors and other quantum well devices. GaAs is used for monolithic radar power amplifiers (but GaN can be less susceptible to heat damage).

Inorganic Reactions + Inorganic Compounds

In the presence of excess arsenic, GaAs boules grow with crystallographic defects; specifically, arsenic antisite defects (an arsenic atom at a gallium atom site within the crystal lattice). The electronic properties of these defects (interacting with others) cause the Fermi level to be pinned to near the center of the band gap, so that this GaAs crystal has very low concentration of electrons and holes. This low carrier concentration is similar to an intrinsic (perfectly undoped) crystal, but much easier to achieve in practice. These crystals are called "semi-insulating", reflecting their high resistivity of 10–10 Ω·cm (which is quite high for a semiconductor, but still much lower than a true insulator like glass).

Inorganic Reactions + Inorganic Compounds

Thin films of lanthanum aluminate were considered as candidate materials for high-k dielectrics in the early-mid 2000s. Despite their attractive relative dielectric constant of ~25, they were not stable enough in contact with silicon at the relevant temperatures (~1000 °C).

Inorganic Reactions + Inorganic Compounds

in sodium hydroxide at 50–70 °C followed by crystallizing the filtered product. If crystallized below 10 °C, the decahydrate forms. Above 10 °C, the dihydate crystallizes. The anhydrous salt is obtained by heating this product at 100 °C.

Inorganic Reactions + Inorganic Compounds

Reaction of 1-norbornyllithium with the ·THF in pentane produces the brown, thermally stable tetrakis(1-norbornyl)cobalt(IV) — a rare example of a stable transition metal/saturated alkane compound, different products are obtained in other solvents.

Inorganic Reactions + Inorganic Compounds

Red iron(III) oxide (FeO, commonly known as rust) is the most common iron oxide used in thermite. Black iron(II,III) oxide (FeO, magnetite) also works. Other oxides are occasionally used, such as MnO in manganese thermite, CrO in chromium thermite, SiO (quartz) in silicon thermite, or copper(II) oxide in copper thermite, but only for specialized purposes. All of these examples use aluminium as the reactive metal. Fluoropolymers can be used in special formulations, Teflon with magnesium or aluminium being a relatively common example. Magnesium/Teflon/Viton is another pyrolant of this type. Combinations of dry ice (frozen carbon dioxide) and reducing agents such as magnesium, aluminium and boron follow the same chemical reaction as with traditional thermite mixtures, producing metal oxides and carbon. Despite the very low temperature of a dry ice thermite mixture, such a system is capable of being ignited with a flame. When the ingredients are finely divided, confined in a pipe and armed like a traditional explosive, this cryo-thermite is detonatable and a portion of the carbon liberated in the reaction emerges in the form of diamond. In principle, any reactive metal could be used instead of aluminium. This is rarely done, because the properties of aluminium are nearly ideal for this reaction: * It forms a passivation layer making it safer to handle than many other reactive metals. * Its relatively low melting point (660 °C) means that it is easy to melt the metal, so that the reaction can occur mainly in the liquid phase, thus it proceeds fairly quickly. * Its high boiling point (2519 °C) enables the reaction to reach very high temperatures, since several processes tend to limit the maximum temperature to just below the boiling point. Such a high boiling point is common among transition metals (e.g., iron and copper boil at 2887 and 2582 °C, respectively), but is especially unusual among the highly reactive metals (cf. magnesium and sodium, which boil at 1090 and 883 °C, respectively). * Further, the low density of the aluminium oxide formed as a result of the reaction tends to leave it floating on the resultant pure metal. This is particularly important for reducing contamination in a weld. Although the reactants are stable at room temperature, they burn with an extremely intense exothermic reaction when they are heated to ignition temperature. The products emerge as liquids due to the high temperatures reached (up to 2500 °C (4532°F) with iron(III) oxide)—although the actual temperature reached depends on how quickly heat can escape to the surrounding environment. Thermite contains its own supply of oxygen and does not require any external source of air. Consequently, it cannot be smothered, and may ignite in any environment given sufficient initial heat. It burns well while wet, and cannot be easily extinguished with water—though enough water to remove sufficient heat may stop the reaction. Small amounts of water boil before reaching the reaction. Even so, thermite is used for welding under water. The thermites are characterized by almost complete absence of gas production during burning, high reaction temperature, and production of molten slag. The fuel should have high heat of combustion and produce oxides with low melting point and high boiling point. The oxidizer should contain at least 25% oxygen, have high density, low heat of formation, and produce metal with low melting and high boiling points (so the energy released is not consumed in evaporation of reaction products). Organic binders can be added to the composition to improve its mechanical properties, but they tend to produce endothermic decomposition products, causing some loss of reaction heat and production of gases. The temperature achieved during the reaction determines the outcome. In an ideal case, the reaction produces a well-separated melt of metal and slag. For this, the temperature must be high enough to melt both reaction products, the resulting metal and the fuel oxide. Too low a temperature produces a mixture of sintered metal and slag; too high a temperature (above the boiling point of any reactant or product) leads to rapid production of gas, dispersing the burning reaction mixture, sometimes with effects similar to a low-yield explosion. In compositions intended for production of metal by aluminothermic reaction, these effects can be counteracted. Too low a reaction temperature (e.g., when producing silicon from sand) can be boosted with addition of a suitable oxidizer (e.g., sulfur in aluminium-sulfur-sand compositions); too high a temperature can be reduced by using a suitable coolant and/or slag flux. The flux often used in amateur compositions is calcium fluoride, as it reacts only minimally, has relatively low melting point, low melt viscosity at high temperatures (therefore increasing fluidity of the slag) and forms a eutectic with alumina. Too much flux, however, dilutes the reactants to the point of not being able to sustain combustion. The type of metal oxide also has dramatic influence to the amount of energy produced; the higher the oxide, the higher the amount of energy produced. A good example is the difference between manganese(IV) oxide and manganese(II) oxide, where the former produces too high temperature and the latter is barely able to sustain combustion; to achieve good results, a mixture with proper ratio of both oxides can be used. The reaction rate can be also tuned with particle sizes; coarser particles burn slower than finer particles. The effect is more pronounced with the particles requiring being heated to higher temperature to start reacting. This effect is pushed to the extreme with nano-thermites. The temperature achieved in the reaction in adiabatic conditions, when no heat is lost to the environment, can be estimated using Hess's law – by calculating the energy produced by the reaction itself (subtracting the enthalpy of the reactants from the enthalpy of the products) and subtracting the energy consumed by heating the products (from their specific heat, when the materials only change their temperature, and their enthalpy of fusion and eventually enthalpy of vaporization, when the materials melt or boil). In real conditions, the reaction loses heat to the environment, the achieved temperature is therefore somewhat lower. The heat transfer rate is finite, so the faster the reaction is, the closer to adiabatic condition it runs and the higher is the achieved temperature.

Inorganic Reactions + Inorganic Compounds

Electrophilic alkylating agents deliver the equivalent of an alkyl cation. Alkyl halides are typical alkylating agents. Trimethyloxonium tetrafluoroborate and triethyloxonium tetrafluoroborate are particularly strong electrophiles due to their overt positive charge and an inert leaving group (dimethyl or diethyl ether). Dimethyl sulfate is intermediate in electrophilicity.

Organic Reactions

Sodium hydroxide has been used for detection of carbon monoxide poisoning, with blood samples of such patients turning to a vermilion color upon the addition of a few drops of sodium hydroxide. Today, carbon monoxide poisoning can be detected by CO oximetry.

Inorganic Reactions + Inorganic Compounds

High-brightness GaN light-emitting diodes (LEDs) completed the range of primary colors, and made possible applications such as daylight visible full-color LED displays, white LEDs and blue laser devices. The first GaN-based high-brightness LEDs used a thin film of GaN deposited via metalorganic vapour-phase epitaxy (MOVPE) on sapphire. Other substrates used are zinc oxide, with lattice constant mismatch of only 2% and silicon carbide (SiC). Group III nitride semiconductors are, in general, recognized as one of the most promising semiconductor families for fabricating optical devices in the visible short-wavelength and UV region.

Inorganic Reactions + Inorganic Compounds

Trifluoroiodomethane is a reagent in aromatic coupling reactions. It has also been used with enones, for example with chalcone, a reaction catalysed by diethyl zinc and Wilkinson's catalyst:

Organic Reactions

Praseodymium(III) nitride forms black crystals of a cubic system. The space group is Fm3m, with cell parameter a = 0.5165 nm, Z = 4, its structure similar to that of sodium chloride (NaCl). The compound is readily hydrolyzed with water and reacts with acids.

Inorganic Reactions + Inorganic Compounds

UF is prepared from UO in a fluidized bed by reaction with HF. The UO is derived from mining operations. Around 60,000 tonnes per year are prepared in this way annually. A common impurity is UOF. UF4 is susceptible to hydrolysis as well. UF is formed by the reaction of UF with hydrogen gas in a vertical tube-type reactor. UF is less stable than the uranium oxides and reacts slowly with moisture at ambient temperature, forming UO and HF, the latter of which is very corrosive and toxic; it is thus less favourable for long-term disposal. The bulk density of UF varies from about 2.0 g/cm to about 4.5 g/cm depending on the production process and the properties of the starting uranium compounds. A molten salt reactor design, a type of nuclear reactor where the working fluid is a molten salt, would use UF as the core material. UF is generally chosen over other salts because of the usefulness of the elements without isotope separation, better neutron economy and moderating efficiency, lower vapor pressure and better chemical stability.

Inorganic Reactions + Inorganic Compounds

The Claus reaction is an example of comproportionation reaction (the inverse of disproportionation) involving hydrogen sulfide () and sulfur dioxide () to produce elemental sulfur and water as follows: The Claus reaction is one of the chemical reactions involved in the Claus process used for the desulfurization of gases in the oil refinery plants and leading to the formation of solid elemental sulfur, more easy to store, transport and dispose off.

Organic Reactions

Some radioactive iodide salts of sodium, including NaI and NaI, have radiopharmaceutical uses for thyroid cancer and hyperthyroidism or as radioactive tracer in imaging (see Isotopes of iodine > Radioiodines I-123, I-124, I-125, and I-131 in medicine and biology).

Inorganic Reactions + Inorganic Compounds

In type I rearrangements (Y-A-B-X conversion to X-A-B-Y) the two migrating groups are oriented trans to each other and as a result of the rearrangement they migrate to opposite sides. The first example of a dyotropic rearrangement involving a carbon-carbon bond was reported by Cyril A. Grob and Saul Winstein. They observed the interconversion of 2 bromine atoms in a certain steroid. In a straightforward example the two bromine atoms in 3-tert-butyl-trans-1,2-dibromohexane mutarotate by heating. In the transition state both bromine atoms connect symmetrically to both carbon atoms on opposite sides and the reaction is concerted. Stepwise mechanisms in dyotropic reactions have also been investigated. In organic synthesis an important application is the conversion of 4-substituted-gamma-lactones to butyrolactones. Type I dyotropic rearrangements also occur around carbon-oxygen bonds, such as the thermal equilibration of (RSi)RC-O-SiR to (RSi)RC-O-SiR. The 1,2-Wittig rearrangement can also be considered an example of this reaction type. More dyotropic reactions are found involving N-O bonds and N-N bonds.

Organic Reactions

The Heck–Matsuda (HM) reaction is an organic reaction and a type of palladium catalysed arylation of olefins that uses arenediazonium salts as an alternative to aryl halides and triflates. The use of arenediazonium salts presents some advantages over traditional aryl halide electrophiles, for example, the use of phosphines as ligand are not required and thus negating the requirement for anaerobic conditions, which makes the reaction more practical and easier to handle. Additionally, the reaction can be performed with or without a base and is often faster than traditional Heck protocols. Allylic alcohols, conjugated alkenes, unsaturated heterocycles and unactivated alkenes are capable of being arylated with arenediazonium salts using simple catalysts such as palladium acetate (Pd(OAc)) or tris(dibenzylideneacetone)dipalladium(0) (Pddba) at room temperature in air, and in benign and conventional solvents. In addition to the intermolecular variant of the HM reaction, intramolecular cyclization processes have also been developed for the construction of a range of oxygen and nitrogen heterocycles. The catalytic cycle for the Heck-Matsuda arylation reaction has four main steps: oxidative addition, migratory insertion or carbopalladation, syn β-elimination and reductive elimination. The proposed Heck catalytic cycle involving cationic palladium with diazonium salts was reinforced by studies with mass spectrometry (ESI) by Correia and co-workers. These results also show the complex interactions that occur in the coordination sphere of palladium during the Heck reaction with arenediazonium salt. A related reaction is the Meerwein arylation that precedes the Heck reaction. Meerwein arylation often use copper salts, but may in some cases be done without a transition metal.

Organic Reactions

Imines may be reduced enantioselectively using stoichiometric amounts of chiral metal hydrides. Such methods have the advantage that they are easy to implement. Reduction with hydrosilanes is a second alternative to transition-metal catalyzed hydrogenation.

Organic Reactions

Wolffram’s Red Salt is an inorganic compound with the double salt formula [Pt(CHNH)Cl] [Pt(CHNH)]Cl·4HO. This compound is an early example of a one-dimensional coordination polymer, serving as a representative structure for studies in solid-state physics. This species has been of interest due to the unusual mixed valence system of Pt(II) and Pt(IV) bridged by a chlorine atom. The deep red color of the double salt, where the components were colorless, piqued the interest of early inorganic chemists and ultimately inspired studies into the physical properties of the compound in search of potential applications.

Inorganic Reactions + Inorganic Compounds

Enantioselective benzylic functionalization reactions depend on the use of enantiomerically pure, planar chiral chromium arene complexes. This section describes methods for the enantioselective synthesis of planar chiral chromium arene complexes, then outlines methods for functionalization of both sp- and sp-hybridized benzylic positions.

Organic Reactions

A versatile dialkylborane is 9-BBN. Also called "banana borane", it exists as a dimer. It can be distilled without decomposition at 195 °C (12mm Hg). Reactions with 9-BBN typically occur at 60–80 °C, with most alkenes reacting within one hour. Tetrasubstituted alkenes add 9-BBN at elevated temperature. Hydroboration of alkenes with 9-BBN proceeds with excellent regioselectivity. It is more sensitive to steric differences than SiaBH, perhaps because of it rigid C backbone. 9-BBN is more reactive towards alkenes than alkynes.

Organic Reactions

Vicinal difunctionalization reactions, most generally, lead to new bonds at two adjacent carbon atoms. Often this takes place in a stereocontrolled fashion, particularly if both bonds are formed simultaneously, as in the Diels-Alder reaction. Activated double bonds represent a useful handle for vicinal difunctionalization because they can act as both nucleophiles and electrophiles—one carbon is necessarily electron poor, and the other electron rich. In the presence of a nucleophile and an electrophile, then, the two carbons of a double bond can act as a "relay," mediating electron flow from the nucleophile to the electrophile with the formation of two, rather than the usual one, chemical bonds. Most often, the nucleophile employed in this context is an organometallic compound and the electrophile is an alkyl halide.

Organic Reactions

Anhydrous zinc chloride is able to melt and boil without any decomposition until 900 °C in an inert atmosphere. However, in the presence of oxygen, zinc chloride oxidizes to zinc oxide above 400 °C. When hydrated zinc chloride is heated, Zn(OH)Cl is produced instead of anhydrous zinc chloride:

Inorganic Reactions + Inorganic Compounds

Disarming sugars can also be accomplished by adding 1,3-dioxane and 1,3-dioxolane protecting groups onto sugars. These protecting groups “lock” the sugars into a rigid chair conformation. When the sugar forms the necessary oxocarbenium ion, it flattens at the anomeric position. This change in configuration is a high-energy transformation when cyclic protecting groups are present, and leads to the sugar being “disarmed”. These groups can be easily removed following glycosylation, effectively “arming” the sugar, and allowing for control of the glycosylation. Further work has shown that the effect of 1,3-dioxanes and 1,3-dioxolanes on disarming sugars can be attributed to the electronics of the systems as well as torsional strain. When a 1,3-dioxane is formed between O-4 and O-6, the oxygens adapt an anti-periplanar geometry with O-5. This orientation allows for hyperconjugation of O-5 to O-4 and O-6, removing electron density from O-5. The loss of electron density at O-5 results in a destabilization of the oxocarbenium ion, slowing its formation, and “disarming” the sugar. Experiments were conducted by altering the configuration of the O-6 and examining the rate of hydrolysis of these compounds. The gauche-gauche orientation seen in the second example has a higher rate of hydrolysis due to its longer bond length. The hydrogen at C-5 is able to hyperconjugate with O-6, effectively lengthening the bond. This increase in bond length decreases the inductive electron withdrawing ability of O-6, causing a higher rate of hydrolysis than the other two conformations. The effect of anti-periplanar orientation is also visible in comparing glucopyranose and galactopyranose hydrolysis. Glucopyranose has an anti-perplanar orientation between O-4 and O-5, while galactopyranose does not and shows the appropriate increase in reactivity.

Organic Reactions

In chemistry, a concerted reaction is a chemical reaction in which all bond breaking and bond making occurs in a single step. Reactive intermediates or other unstable high energy intermediates are not involved. Concerted reaction rates tend not to depend on solvent polarity ruling out large buildup of charge in the transition state. The reaction is said to progress through a concerted mechanism as all bonds are formed and broken in concert. Pericyclic reactions, the S2 reaction, and some rearrangements - such as the Claisen rearrangement - are concerted reactions. The rate of the S2 reaction is second order overall due to the reaction being bimolecular (i.e. there are two molecular species involved in the rate-determining step). The reaction does not have any intermediate steps, only a transition state. This means that all the bond making and bond breaking takes place in a single step. In order for the reaction to occur both molecules must be situated correctly.

Organic Reactions

The complex [Ru(o-CHPPh)(H)(CO)(PPh)] catalyzes the Murai reaction at room temperature. For [Ru(H)(H)(PR)], the active complex is [Ru(H)(PR)]. After the active form of the ruthenium catalyst complex is generated from 1, acetophenone coordinates to the complex via its carbonyl oxygen and agostically via its ortho C-H bond (2). As in the Ru proposed mechanism, this agostic interaction leads to the oxidative addition of the ortho C-H. Reductive elimination releases H, which remains coordinated, giving complex 3. Coordination of ethylene and decoordination of the ketone results in complex 4 which then undergoes migratory insertion of ethylene into the hydride to give 5. Following oxidative addition of H (6), the complex reductively eliminates the product to give the product agostically bound to the complex. Coordination of another acetophenone molecule regenerates complex 2.

Organic Reactions

Through hot-isostatically pressing (HIP) a ZrWO-Cu composite (system) can be realized. Work done by C. Verdon and D.C. Dunand in 1997 used similarly sized zirconium tungstate and copper powder in a low carbon steel can coated with Cu, and they were HIPed under 103MPa pressure for 3 hours at 600 °C. A control experiment was also conducted, with only a heat treatment (i.e., no pressing) for the same powder mixture also under 600 °C for 3 hours in a quartz tube gettered with titanium. The results from X-ray diffraction (XRD) in the graph in Verdon & Dunand's paper shows expected products. (a) is from the as received zirconium tungstate powder, (b) is the result from the control experiment , and (c) is the ceramic product from the HIP process. Apparently there are new phases formed according to Spectrum (c) with no ZrWO left. While for the control experiment only partial amount of ZrWO was decomposed. While complex oxides containing Cu, Zr, and W were believed to be created, selected area diffraction (SAD) of the ceramic product has proven the existence of CuO as precipitates after reaction. A model consisted of two concurrent processes were surmised (as presented): (b) the decomposition of the ceramic and loss of oxygen under low oxygen partial pressure at high temperature leads to CuO formation; (c) copper diffuses into the ceramic and forms new oxides that absorb some oxygen upon cooling. Since only very few oxides, those of noble metals which are very expensive, are less stable than CuO and CuO was believed to be more stable than ZrWO, kinetic control of the reaction must be taken into account. For example, reducing reaction time and temperature helps alleviate the residual stress caused by different phases of the ceramic during reaction, which could lead to a delamination of the ceramic particles from the matrix and an increase in the CTE.

Inorganic Reactions + Inorganic Compounds

In a similar fashion, sodium hydroxide is used to digest tissues, as in a process that was used with farm animals at one time. This process involved placing a carcass into a sealed chamber, then adding a mixture of sodium hydroxide and water (which breaks the chemical bonds that keep the flesh intact). This eventually turns the body into a liquid with a dark brown color, and the only solids that remain are bone hulls, which can be crushed between one's fingertips. Sodium hydroxide is frequently used in the process of decomposing roadkill dumped in landfills by animal disposal contractors. Due to its availability and low cost, it has been used by criminals to dispose of corpses. Italian serial killer Leonarda Cianciulli used this chemical to turn dead bodies into soap. In Mexico, a man who worked for drug cartels admitted disposing of over 300 bodies with it. Sodium hydroxide is a dangerous chemical due to its ability to hydrolyze protein. If a dilute solution is spilled on the skin, burns may result if the area is not washed thoroughly and for several minutes with running water. Splashes in the eye can be more serious and can lead to blindness.

Inorganic Reactions + Inorganic Compounds

Borate anions (and functional groups) consist of trigonal planar and/or tetrahedral structural units, joined together via shared oxygen atoms (corners) or atom pairs (edges) into larger clusters so as to construct various ions such as , , , , , etc. These anions may be cyclic or linear in structure, and can further polymerize into infinite chains, layers, and tridimensional frameworks. The terminal (unshared) oxygen atoms in the borate anions may be capped with hydrogen atoms () or may carry a negative charge (). The planar units may be stacked in the crystal lattice so as to have π-conjugated molecular orbitals, which often results in useful optical properties such as strong harmonics generation, birefringence, and UV transmission. Polymeric borate anions may have linear chains of 2, 3 or 4 trigonal structural units, each sharing oxygen atoms with adjacent unit(s). as in lithium metaborate|, contain chains of trigonal structural units. Other anions contain cycles; for instance, Sodium metaborate| and contain the cyclic ion, consisting of a six-membered ring of alternating boron and oxygen atoms with one extra oxygen atom attached to each boron atom. The thermal expansion of crystalline borates is dominated by the fact that and polyhedra and rigid groups consisting of these polyhedra practically do not change their configuration and size upon heating, but sometimes rotate like hinges, which results in greatly anisotropic thermal expansion including linear negative expansion.

Inorganic Reactions + Inorganic Compounds

The earliest observation of a cycloheptadiene via the title rearrangement was made by Baeyer in his synthesis of eucarvone from carvone hydrobromide. Mechanistic studies revealed that the rearrangement did indeed proceed via a concerted, Cope-type mechanism. In the Eschenmoser synthesis of colchicine, the rearrangement is used to form the seven-membered ring of the target. A racemic synthesis of sirenin employs a Wittig reaction to form the key divinylcyclopropane. Hydrogenation of the rearrangement product afforded the target.

Organic Reactions

Molybdenum(V) chloride is the inorganic compound with the empirical formula . This dark volatile solid is used in research to prepare other molybdenum compounds. It is moisture-sensitive and soluble in chlorinated solvents.

Inorganic Reactions + Inorganic Compounds

Trifluoromethanesulfonyl chloride (or triflyl chloride, CF3SO2Cl) can be used in a highly efficient method to introduce a trifluoromethyl group to aromatic and heteroaromatic systems, including known pharmaceuticals such as Lipitor. The chemistry is general and mild, and uses a photoredox catalyst and a light source at room temperature.

Organic Reactions

The general methodology of TAP data analysis, developed in a series of papers by Grigoriy (Gregory) Yablonsky is based on comparing an inert gas response which is controlled only by Knudsen diffusion with a reactive gas response which is controlled by diffusion as well as adsorption and chemical reactions on the catalyst sample. TAP pulse-response experiments can be effectively modeled by a one-dimensional (1D) diffusion equation with uniquely simple combination of boundary conditions.

Inorganic Reactions + Inorganic Compounds

The Danheiser annulation or Danheiser TMS-cyclopentene annulation is an organic reaction of an α,β-unsaturated ketone and a trialkylsilylallene (e.g., trimethylsilyl- or triisopropylsilyl-) in the presence of a Lewis Acid to give a trialkylsilylcyclopentene in a regiocontrolled annulation.

Organic Reactions

Carbohydrate synthesis is a sub-field of organic chemistry concerned with generating complex carbohydrate structures from simple units (monosaccharides) through natural or unnatural processes. The generation of carbohydrate structures involves linking glycosyl groups like monosaccharides or oligosaccharides through glycosidic bonds is called glycosylation. Carbohydrate synthesis aims to generate the polysaccharides with controlled structures through atomically economic methods. Therefore, it is important to construct glycosidic linkages that have optimum molecular geometry (stereoselectivity) and the stable bond (regioselectivity) at the reaction site (anomeric centre).

Organic Reactions

Lanthanum aluminate is an inorganic compound with the formula LaAlO, often abbreviated as LAO. It is an optically transparent ceramic oxide with a distorted perovskite structure.

Inorganic Reactions + Inorganic Compounds

Temporal Analysis of Products (TAP), (TAP-2), (TAP-3) is an experimental technique for studying the kinetics of physico-chemical interactions between gases and complex solid materials, primarily heterogeneous catalysts. The TAP methodology is based on short pulse-response experiments at low background pressure (10-10 Pa), which are used to probe different steps in a catalytic process on the surface of a porous material including diffusion, adsorption, surface reactions, and desorption.

Inorganic Reactions + Inorganic Compounds

Transglycosylation, which involves the reversible transfer of a sugar moiety from one heterocyclic base to another, is effective for the conversion of pyrimidine nucleosides to purine nucleosides. Most other transglycosylation reactions are low yielding due to a small thermodynamic difference between equilibrating nucleosides. Deoxyribose-derived electrophiles are unable to form the cyclic cation 1; as a result, the stereoselective synthesis of deoxyribonucleosides is more difficult than the synthesis of ribonucleosides. One solution to this problem involves the synthesis of a ribonucleoside, followed by protection of the 3- and 5-hydroxyl groups, removal of the 2'-hydroxyl group through a Barton deoxygenation, and deprotection.

Organic Reactions

Evidence suggests that NS can react with itself to reach NS, NS, and polymers of the form (NS). (NS) forms from polymerization of cyclo-NS. Trans-NSSN results from direct dimerization of NS. NS has been observed through photoelectron spectroscopy of vapors of the (SN), polymer, but has not yet been characterized further. Attempts to produce NS by oxidation of [PPN] [SN] were unsuccessful. Its theorized that rapid dimerization to (NS) will disproportionate irreversibly to NS and NS.

Inorganic Reactions + Inorganic Compounds

The Wöhler synthesis is the conversion of ammonium cyanate into urea. This chemical reaction was described in 1828 by Friedrich Wöhler. It is often cited as the starting point of modern organic chemistry. Although the Wöhler reaction concerns the conversion of ammonium cyanate, this salt appears only as an (unstable) intermediate. Wöhler demonstrated the reaction in his original publication with different sets of reactants: a combination of cyanic acid and ammonia, a combination of silver cyanate and ammonium chloride, a combination of lead cyanate and ammonia and finally from a combination of mercury cyanate and cyanatic ammonia (which is again cyanic acid with ammonia).

Organic Reactions

In chemistry, oxychlorination is a process for generating the equivalent of chlorine gas (Cl) from hydrogen chloride and oxygen. This process is attractive industrially because hydrogen chloride is less expensive than chlorine.

Organic Reactions

Hydrogen for the reduction of C=N double bond can either be provided by hydrogen gas (H) or transferred from sources of H, such as alcohols and formic acid. The process is usually catalyzed by transition metal complexes. For metal catalyzed reactions, the transfer of H to the imine can proceed by either inner sphere or outer sphere mechanisms.

Organic Reactions

Halogenation of saturated hydrocarbons is a substitution reaction. The reaction typically requires free radical pathways. The regiochemistry of the halogenation of alkanes is largely determined by the relative weakness of the C–H bonds. This trend is reflected by the faster reaction at tertiary and secondary positions. Fluorinations with elemental fluorine () are particularly exothermic, so much so that highly specialised conditions and apparatus are required. The method electrochemical fluorination generates small amounts of elemental fluorine in situ from hydrogen fluoride. The method avoids the hazards of handling fluorine gas. Many commercially important organic compounds are fluorinated using this technology. Aside from and its electrochemically generated equivalent, cobalt(III) fluoride is used as sources of fluorine radicals. Free radical chlorination is used for the industrial production of some solvents: Naturally-occurring organobromine compounds are usually produced by free radical pathway catalyzed by the enzyme bromoperoxidase. The reaction requires bromide in combination with oxygen as an oxidant. The oceans are estimated to release 1–2 million tons of bromoform and 56,000 tons of bromomethane annually. The iodoform reaction, which involves degradation of methyl ketones, proceeds by the free radical iodination.

Organic Reactions

Traditionally, aryl amination is difficult reaction which usually requires "activated" aryl halides, such as those with strong electron-withdrawing groups such as nitro groups ortho or para to the halogen atom. For the arylation of amines with unactivated aryl halides, the Buchwald-Hartwig reaction is useful. In this process, palladium complexes serve as catalysts.

Organic Reactions

The radical decay time of NS alone is on the order of 1-3 ms. As evident by no change to this decay time upon addition of NO or O at ambient temperatures, the NS radical is unreactive with NO and O. However, rapid, first-order decay is observed with the addition of NO. This reaction is proposed to proceed through various intermediates, ultimately reaching final products of N and SO. This rapid reaction occurs with a rate constant of k = (2.54 ± 0.12) × 10 cm molecules s at 295 K. By use of Density Functional Theory based computational calculations, the minima and transition states of the potential energy surface of this reaction have been predicted.

Inorganic Reactions + Inorganic Compounds

Three modes allow the addition of allylstannanes to carbonyls: thermal addition, Lewis-acid-promoted addition, and addition involving prior transmetalation. Each of these modes invokes a unique model for stereocontrol, but in all cases, a distinction is made between reagent and substrate control. Substrate-controlled additions typically involve chiral aldehydes or imines and invoke the Felkin-Anh model. When all reagents are achiral, only simple diastereoselectivity (syn versus anti, see above) must be considered. Addition takes place via an S' mechanism involving concerted dissociation of tin and C-C bond formation at the γ position. With the allylstannane and aldehyde in high-temperature conditions, addition proceeds through a six-membered, cyclic transition state, with the tin center serving as an organizing element. The configuration of the double bond in the allylstannane controls the sense of diastereoselectivity of the reaction. This is not the case in Lewis-acid-promoted reactions, in which either the (Z)- or (E)-stannane affords the syn product predominantly (Type II). The origin of this selectivity has been debated, and depends on the relative energies of a number of acyclic transition states. (E)-Stannanes exhibit higher syn selectivity than the corresponding (Z)-stannanes. In the presence of certain Lewis acids, transmetalation may occur before addition. Complex reaction mixtures may result if transmetalation is not complete or if an equilibrium between allylic isomers exists. Tin(IV) chloride and indium(III) chloride have been employed for useful reactions in this mode.

Organic Reactions

Dilute aqueous zinc chloride was used as a disinfectant under the name "Burnett's Disinfecting Fluid". From 1839 Sir William Burnett promoted its use as a disinfectant as well as a wood preservative. The Royal Navy conducted trials into its use as a disinfectant in the late 1840s, including during the cholera epidemic of 1849; and at the same time experiments were conducted into its preservative properties as applicable to the shipbuilding and railway industries. Burnett had some commercial success with his eponymous fluid. Following his death however, its use was largely superseded by that of carbolic acid and other proprietary products.

Inorganic Reactions + Inorganic Compounds

The salt is prepared by the addition of elemental sulfur to potassium sulfide. An idealized equation is shown for potassium hydrosulfide: The structure consists of zigzag chains of paired with ions.

Inorganic Reactions + Inorganic Compounds

A strong base deprotonates the dicarbonyl α-carbon. This carbon is preferred over the methyl carbon because the formed enolate is conjugated and thus resonance stabilized. The carbon then undergoes nucleophilic substitution. When heated with aqueous acid, the newly alkylated ester is hydrolyzed to a β-keto acid, which is decarboxylated to form a methyl ketone.

Organic Reactions

is stable to air. It is, however, unstable in the thermodynamic sense with a positive enthalpy of formation of +460 kJ/mol. This endothermic enthalpy of formation originates in the difference in energy of compared to its highly stable decomposition products: Because one of its decomposition products is a gas, can be used as an explosive. Purer samples tend to be more explosive. Small samples can be detonated by striking with a hammer. is thermochromic, changing from pale yellow below −30 °C to orange at room temperature to deep red above 100 °C.

Inorganic Reactions + Inorganic Compounds

Scandium(III) sulfide is a chemical compound of scandium and sulfur with the chemical formula ScS. It is a yellow solid.

Inorganic Reactions + Inorganic Compounds

In a conventional oil refinery, isobutane is alkylated with low-molecular-weight alkenes (primarily a mixture of propene and butene) in the presence of a Brønsted acid catalyst, which can include solid acids (zeolites). The catalyst protonates the alkenes (propene, butene) to produce carbocations, which alkylate isobutane. The product, called "alkylate", is composed of a mixture of high-octane, branched-chain paraffinic hydrocarbons (mostly isoheptane and isooctane). Alkylate is a premium gasoline blending stock because it has exceptional antiknock properties and is clean burning. Alkylate is also a key component of avgas. By combining fluid catalytic cracking, polymerization, and alkylation, refineries can obtain a gasoline yield of 70 percent. The widespread use of sulfuric acid and hydrofluoric acid in refineries poses significant environmental risks. Ionic liquids are used in place of the older generation of strong Bronsted acids.

Organic Reactions

Sodium hydroxide is used in some cement mix plasticisers. This helps homogenise cement mixes, preventing segregation of sands and cement, decreases the amount of water required in a mix and increases workability of the cement product, be it mortar, render or concrete.

Inorganic Reactions + Inorganic Compounds

Thermite usage is hazardous due to the extremely high temperatures produced and the extreme difficulty in smothering a reaction once initiated. Small streams of molten iron released in the reaction can travel considerable distances and may melt through metal containers, igniting their contents. Additionally, flammable metals with relatively low boiling points such as zinc (with a boiling point of 907 °C, which is about 1,370 °C below the temperature at which thermite burns) could potentially spray superheated boiling metal violently into the air if near a thermite reaction. If, for some reason, thermite is contaminated with organics, hydrated oxides and other compounds able to produce gases upon heating or reaction with thermite components, the reaction products may be sprayed. Moreover, if the thermite mixture contains enough empty spaces with air and burns fast enough, the super-heated air also may cause the mixture to spray. For this reason it is preferable to use relatively crude powders, so the reaction rate is moderate and hot gases could escape the reaction zone. Preheating of thermite before ignition can easily be done accidentally, for example by pouring a new pile of thermite over a hot, recently ignited pile of thermite slag. When ignited, preheated thermite can burn almost instantaneously, releasing light and heat energy at a much higher rate than normal and causing burns and eye damage at what would normally be a reasonably safe distance. The thermite reaction can take place accidentally in industrial locations where workers use abrasive grinding and cutting wheels with ferrous metals. Using aluminium in this situation produces a mixture of oxides that can explode violently. Mixing water with thermite or pouring water onto burning thermite can cause a steam explosion, spraying hot fragments in all directions. Thermites main ingredients were also utilized for their individual qualities, specifically reflectivity and heat insulation, in a paint coating or dope for the German zeppelin Hindenburg, possibly contributing to its fiery destruction. This was a theory put forward by the former NASA scientist Addison Bain, and later tested in small scale by the scientific reality-TV show MythBusters with semi-inconclusive results (it was proven not to be the fault of the thermite reaction alone, but instead conjectured to be a combination of that and the burning of hydrogen gas that filled the body of the Hindenburg). The MythBusters' program also tested the veracity of a video found on the Internet, whereby a quantity of thermite in a metal bucket was ignited while sitting on top of several blocks of ice, causing a sudden explosion. They were able to confirm the results, finding huge chunks of ice as far as 50 m from the point of explosion. Co-host Jamie Hyneman conjectured that this was due to the thermite mixture aerosolizing, perhaps in a cloud of steam, causing it to burn even faster. Hyneman also voiced skepticism about another theory explaining the phenomenon: that the reaction somehow separated the hydrogen and oxygen in the ice and then ignited them. This explanation claims that the explosion is due to the reaction of high temperature molten aluminium with water. Aluminium reacts violently with water or steam at high temperatures, releasing hydrogen and oxidizing in the process. The speed of that reaction and the ignition of the resulting hydrogen can easily account for the explosion verified. This process is akin to the explosive reaction caused by dropping metallic potassium into water.

Inorganic Reactions + Inorganic Compounds

Sodium hydroxide is used to detect the presence of flavonoids. About 5 mg of a compound is dissolved in water, warmed, and filtered. 10% aqueous sodium hydroxide is added to 2 ml of this solution. This produces a yellow coloration. A change in color from yellow to colorless on addition of dilute hydrochloric acid is an indication for the presence of flavonoids.

Inorganic Reactions + Inorganic Compounds

The orthoborate ion is known in the solid state, for example, in calcium orthoborate , where it adopts a nearly trigonal planar structure. It is a structural analogue of the carbonate anion , with which it is isoelectronic. Simple bonding theories point to the trigonal planar structure. In terms of valence bond theory, the bonds are formed by using sp hybrid orbitals on boron. Some compounds termed orthoborates do not necessarily contain the trigonal planar ion. For example, gadolinium orthoborate contains the planar ion only a high temperatures; otherwise it contains the polyborate anion .

Inorganic Reactions + Inorganic Compounds

Naturally occurring minerals that are sometimes given the chemical name, sodium aluminosilicate include albite (NaAlSiO, an end-member of the plagioclase series) and jadeite (NaAlSiO).

Inorganic Reactions + Inorganic Compounds

Copper thermite can be prepared using either copper(I) oxide (CuO, red) or copper(II) oxide (CuO, black). The burn rate tends to be very fast and the melting point of copper is relatively low, so the reaction produces a significant amount of molten copper in a very short time. Copper(II) thermite reactions can be so fast that it can be considered a type of flash powder. An explosion can occur, which sends a spray of copper drops to considerable distances. Oxygen-balanced mixture has theoretical maximum density of 5.109 g/cm, adiabatic flame temperature 2843 K (phase transitions included) with the aluminium oxide being molten and copper in both liquid and gaseous form; 343 g of copper vapor per kg of this thermite are produced. The energy content is 974 cal/g. Copper(I) thermite has industrial uses in e.g., welding of thick copper conductors (cadwelding). This kind of welding is being evaluated also for cable splicing on the US Navy fleet, for use in high-current systems, e.g., electric propulsion. Oxygen balanced mixture has theoretical maximum density of 5.280 g/cm, adiabatic flame temperature 2843 K (phase transitions included) with the aluminium oxide being molten and copper in both liquid and gaseous form; 77.6 g of copper vapor per kg of this thermite are produced. The energy content is 575.5 cal/g.

Inorganic Reactions + Inorganic Compounds

serves as a Lewis base by binding through nitrogen to strongly Lewis acidic compounds such as Antimony pentachloride| and Sulfur trioxide|. The cage is distorted in these adducts. The reaction of with is reported to form a complex where a sulfur forms a dative bond to the metal. This compound upon standing is isomerised to a complex in which a nitrogen atom forms the additional bond to the metal centre. It is protonated by Tetrafluoroboric acid| to form a tetrafluoroborate salt: The soft Lewis acid CuCl forms a coordination polymer: Dilute NaOH hydrolyzes as follows, yielding thiosulfate and trithionate: More concentrated base yields sulfite:

Inorganic Reactions + Inorganic Compounds

Type II rearrangements often involve double hydrogen migration in a carbon skeleton. This reaction type can be found in certain transfer hydrogenations. An example is hydrogen transfer in syn-sesquinorbornene disulfones.

Organic Reactions

Praseodymium(IV) fluoride forms light yellow crystals. The crystal structure is anticubic and isomorphic to that of uranium tetrafluoride UF. It decomposes when heated: Due to the high normal potential of the tetravalent praseodymium cations (Pr3+ / Pr4+: +3.2 V), praseodymium(IV) fluoride decomposes in water, releasing oxygen, O.

Inorganic Reactions + Inorganic Compounds

Adenoviral E1A-associated protein of 300kDa (p300) and the CREB-binding protein (CBP) make up the next family of HATs. This family of HATs contain HAT domains that are approximately 500 residues long and contain bromodomains as well as three cysteine-histidine rich domains that help with protein interactions. These HATs are known to acetylate all of the histone subunits in the nucleosome. They also have the ability to acetylate and mediate non-histone proteins involved in transcription and are also involved in the cell-cycle, differentiation and apoptosis.

Organic Reactions

Source: n-Butyllithium (14.0 mL of a 2.5 M solution in hexane, 35 mmol) was added dropwise to a solution of 2,6-dimethylanisole (4.95 mL, 35 mmol) in 60 mL of tetrahydrofuran at 0°, and the resulting solution was stirred at 0° for 1 hour and then at ambient temperature for 4 hours. The reaction mixture was cooled to 0°, treated with cyclohexanecarboxaldehyde (4.2 mL, 35 mmol), allowed to warm to ambient temperature again, and poured into saturated aqueous ammonium chloride solution. The mixture was extracted with ether and the ether extract was washed with water and brine and concentrated in vacuo. The residue was purified by silica gel chromatography (hexane-ether, 5:1 v/v) to give 4.2 g (48%) of the product as a colorless oil; H NMR (CDCl) δ 1.05–1.50 (m, 6H), 1.64–1.82 (m, 4H), 1.92 (m, 1H), 2.28 (d, 1H, J = 3 Hz), 2.31 (s, 3H), 2.68 (dd, 1H, J = 10, 13 Hz), 2.85 (dd, 1H, J = 3, 13 Hz), 3.57 (m, 1H), 3.75 (s, 3H), 6.95–7.10 (m, 3H).

Organic Reactions

Methylation, in the chemical sciences, is the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These terms are commonly used in chemistry, biochemistry, soil science, and biology. In biological systems, methylation is catalyzed by enzymes; such methylation can be involved in modification of heavy metals, regulation of gene expression, regulation of protein function, and RNA processing. In vitro methylation of tissue samples is also a way to reduce some histological staining artifacts. The reverse of methylation is demethylation.

Organic Reactions

Vinyl and aryl Grignard reagents couple with primary alkyl halides in the presence of a catalytic amount of a copper(I) halide salt. The use of LiCuCl rather than simple copper(I) halide salts (CuX) improves yields of these coupling reactions. The addition of Grignard reagents to alkynes is facilitated by a catalytic amount of copper halide. Transmetalation to copper and carbocupration are followed by transmetalation of the product alkene back to magnesium. The addition is syn unless a coordinating group is nearby in the substrate, in which case the addition becomes anti and yields improve.

Organic Reactions

*The Inorganic Crystal Structure Database (ICSD) in its definition of "inorganic" carbon compounds, states that such compounds may contain either C-H or C-C bonds, but not both. *The book series Inorganic Syntheses does not define inorganic compounds. The majority of its content deals with metal complexes of organic ligands. *IUPAC does not offer a definition of "inorganic" or "inorganic compound" but does define inorganic polymer as "...skeletal structure that does not include carbon atoms."

Inorganic Reactions + Inorganic Compounds

XeO should be handled with great caution. Samples have detonated when undisturbed at room temperature. Dry crystals react explosively with cellulose.

Inorganic Reactions + Inorganic Compounds

Neptunium diarsenide forms crystals of the tetragonal system, space group P4/nmm, cell parameters a = 0.3958 nm, c = 0.8098 nm.

Inorganic Reactions + Inorganic Compounds

GaN-based violet laser diodes are used to read Blu-ray Discs. The mixture of GaN with In (InGaN) or Al (AlGaN) with a band gap dependent on the ratio of In or Al to GaN allows the manufacture of light-emitting diodes (LEDs) with colors that can go from red to ultra-violet.

Inorganic Reactions + Inorganic Compounds

The Class IIB HDACs include HDAC6 and HDAC10. These two HDACs are most closely related to each other in overall sequence. However, HDAC6's catalytic domain is most similar to HDAC9. A unique feature of HDAC6 is that it contains two catalytic domains in tandem of one another. Another unique feature of HDAC6 is the HDAC6-, SP3, and Brap2-related zinc finger motif (HUB) domain in the C-terminus which shows some functions related to ubiquitination, meaning this HDAC is prone to degradation. HDAC10 has two catalytic domains as well. One active domain is located in the N-terminus and a putative catalytic domain is located in the C-terminus along with an NES domain. Two putative Rb-binding domains have also been found on HDAC10 which shows it may have roles in the regulation of the cell cycle. Two variants of HDAC10 have been found, both having slight differences in length. HDAC6 is the only HDAC to be shown to act on tubulin, acting as a tubulin deacetylase which helps in the regulation of microtubule-dependent cell motility. It is mostly found in the cytoplasm but has been known to be found in the nucleus, complexed together with HDAC11. HDAC10 has been seen to act on HDACs 1, 2, 3 (or SMRT), 4, 5 and 7. Some evidence has been shown that it may have small interactions with HDAC6 as well. This leads researchers to believe that HDAC10 may function more as a recruiter rather than a factor for deacetylation. However, experiments conducted with HDAC10 did indeed show deacetylation activity.

Organic Reactions

Sodium hydroxide is also widely used in pulping of wood for making paper or regenerated fibers. Along with sodium sulfide, sodium hydroxide is a key component of the white liquor solution used to separate lignin from cellulose fibers in the kraft process. It also plays a key role in several later stages of the process of bleaching the brown pulp resulting from the pulping process. These stages include oxygen delignification, oxidative extraction, and simple extraction, all of which require a strong alkaline environment with a pH > 10.5 at the end of the stages.

Inorganic Reactions + Inorganic Compounds

Histone Acetyltransferases, also known as HATs, are a family of enzymes that acetylate the histone tails of the nucleosome. This, and other modifications, are expressed based on the varying states of the cellular environment. Many proteins with acetylating abilities have been documented and, after a time, were categorized based on sequence similarities between them. These similarities are high among members of a family, but members from different families show very little resemblance. Some of the major families identified so far are as follows.

Organic Reactions