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Theory U

Theory U is a change management method and the title of a book by Otto Scharmer. During his doctoral studies at Witten/Herdecke University, Scharmer studied a similar method in classes taught by Friedrich Glasl, whom he also interviewed. Scharmer ...

Acid hydrolysis

In organic chemistry, acid hydrolysis is a process in which a protic acid is used to catalyze the cleavage of a chemical bond via a nucleophilic substitution reaction, with the addition of the elements of water. For example, in the conversion of ...

Addition reaction

An addition reaction, in organic chemistry, is in its simplest terms an organic reaction where two or more molecules combine to form a larger one. Addition reactions are limited to chemical compounds that have multiple bonds, such as molecules wi ...

Adduct

An adduct is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is considered a distinct molecular species. Examples include the addition ...

Adduct purification

Adduct purification is a technique for preparing extremely pure simple organometallic compounds, which are generally unstable and hard to handle, by purifying a stable adduct with a Lewis acid and then obtaining the desired product from the pure ...

Air–fuel ratio

Air–fuel ratio is the mass ratio of air to a solid, liquid, or gaseous fuel present in a combustion process. The combustion may take place in a controlled manner such as in an internal combustion engine or industrial furnace, or may result in an ...

Alkali–aggregate reaction

Alkali–aggregate reaction is a term mainly referring to a reaction which occurs over time in concrete between the highly alkaline cement paste and non-crystalline silicon dioxide, which is found in many common aggregates. This reaction can cause ...

Alkali–carbonate reaction

The alkali–carbonate reaction is a process suspected for the degradation of concrete containing dolomite aggregate. Alkali from the cement might react with the dolomite crystals present in the aggregate inducing the production of brucite, MgOH 2, ...

Alkali–silica reaction

The alkali–silica reaction, more commonly known as "concrete cancer", is a swelling reaction that occurs over time in concrete between the highly alkaline cement paste and the reactive non-crystalline silica found in many common aggregates, given ...

Alkaline hydrolysis

Alkaline hydrolysis, in organic chemistry, usually refers to types of nucleophilic substitution reactions in which the attacking nucleophile is a hydroxide ion.

Anaerobic glycolysis

Anaerobic glycolysis is the transformation of glucose to lactate when limited amounts of oxygen are available. Anaerobic glycolysis is only an effective means of energy production during short, intense exercise, providing energy for a period rang ...

Arrow pushing

Arrow pushing or electron pushing is a technique used to describe the progression of organic chemistry reaction mechanisms. It was first developed by Sir Robert Robinson. In using arrow pushing, "curved arrows" or "curly arrows" are superimposed ...

Associative substitution

Associative substitution describes a pathway by which compounds interchange ligands. The terminology is typically applied to coordination and organometallic complexes, but resembles the Sn2 mechanism in organic chemistry. The opposite pathway is ...

Asymmetric addition of alkenylmetals to aldehydes

Asymmetric addition of alkenylmetals to aldehydes is a chemical reaction in enantioselective synthesis that reacts an alkenylmetal with an aldehyde to give an allyl alcohol. The stereoselectivity in the reaction is typically controlled by the asy ...

Auxochrome

An auxochrome is a group of atoms attached to a chromophore which modifies the ability of that chromophore to absorb light. They themselves fail to produce the colour; but when present along with the chromophores in an organic compound intensifie ...

Bargellini reaction

The Bargellini reaction is a chemical reaction discovered in 1906 by Italian chemist Guido Bargellini. The original reaction was a mixture of the reagents phenol, chloroform, and acetone in the presence of a sodium hydroxide solution. Prior to Ba ...

Barking dog reaction

The Barking Dog is an exothermic chemical reaction that results from the ignition of a mixture of carbon disulfide and nitrous oxide. When ignited in a cylindrical tube, the reaction produces a bright flash and a loud "woof" - reminiscent of a ba ...

Bergmann azlactone peptide synthesis

The Bergmann azlactone peptide synthesis is a classic organic synthesis process for the preparation of dipeptides. In the presence of a base, peptides are formed. s of N-carboxyanhydrides of amino acids with amino acid esters 1. This reaction can ...

Beta-carbon elimination

β-carbon elimination is a type of reaction in organometallic chemistry wherein an allyl ligand bonded to a metal center is broken into the corresponding metal-bonded alkyl ligand and an alkene. It is a subgroup of elimination reactions. Though le ...

Bioorthogonal chemistry

The term bioorthogonal chemistry refers to any chemical reaction that can occur inside of living systems without interfering with native biochemical processes. The term was coined by Carolyn R. Bertozzi in 2003. Since its introduction, the concep ...

Boekelheide reaction

The Boekelheide reaction is a rearrangement of α-picoline- N -oxides to hydroxymethylpyridines. It is named after Virgil Boekelheide who first reported it in 1954. Originally the reaction was carried out using acetic anhydride, which typically re ...

Browning in red wine

Oxidation and reduction in red wines can lead to a particularly undesirable brick red color in red wines. This process is sometimes referred to as browning. In chemical terms, this is called a redox reaction because first the color of the wine de ...

Captodative effect

The captodative effect is the stabilization of radicals by a synergistic effect of an electron-withdrawing substituent and an electron-donating substituent. The name originates as the electron-withdrawing group is sometimes called the "captor" gr ...

Carboalkoxylation

In industrial chemistry, carboalkoxylation is a process for converting alkenes to esters. Also called hydroesterification, this reaction is a form of carbonylation. A closely related reaction is hydrocarboxylation, which employs water in place of ...

Carbonylation

Carbonylation refers to reactions that introduce carbon monoxide into organic and inorganic substrates. Carbon monoxide is abundantly available and conveniently reactive, so it is widely used as a reactant in industrial chemistry. The term carbon ...

Carbothermic reaction

Carbothermic reactions involve the reduction of substances, often metal oxides, using carbon as the reducing agent. These chemical reactions are usually conducted at temperatures of several hundred degrees Celsius. Such processes are applied for ...

Catalysis

Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst, which is not consumed in the catalyzed reaction and can continue to act repeatedly. Because of this, only very small amounts of cata ...

Catalytic resonance theory

In chemistry, catalytic resonance theory was developed by Paul Dauenhauer to describe the kinetics of reaction acceleration using dynamic catalyst surfaces. Catalytic reactions occurring on surfaces that undergo variation in surface binding energ ...

Catellani reaction

The Catellani reaction was discovered by Marta Catellani and co-workers in 1997. The reaction uses aryl iodides to perform bi- or tri-functionalization, including C-H functionalization of the unsubstituted ortho position, followed a terminating c ...

Cerium(IV) oxide–cerium(III) oxide cycle

The cerium oxide–cerium oxide cycle or CeO 2 /Ce 2 O 3 cycle is a two-step thermochemical process that employs cerium oxide and cerium oxide for hydrogen production. The cerium-based cycle allows the separation of H 2 and O 2 in two steps, making ...

Chain scission

Chain scission is a term used in polymer chemistry describing the degradation of a polymer main chain. It is often caused by thermal stress or ionizing radiation, often involving oxygen. During chain cleavage, the polymer chain is broken at a ran ...

Chemical clock

A chemical clock is a complex mixture of reacting chemical compounds in which the onset of an observable property occurs after a predictable induction time. In cases where one of the reagents has a visible color, crossing a concentration threshol ...

Chemical decomposition

Chemical decomposition is the breakdown of a single entity into two or more fragments. Chemical decomposition is usually regarded and defined as the exact opposite of chemical synthesis. In short, the chemical reaction in which two or more produc ...

Chemical kinetics

Chemical kinetics, also known as reaction kinetics, is the branch of physical chemistry that is concerned with understanding the rates of chemical reactions. It is to be contrasted with thermodynamics, which deals with the direction in which a pr ...

Chemical process of decomposition

Decomposition in animals is a process that begins immediately after death and involves the destruction of soft tissue, leaving behind skeletonized remains. The chemical process of decomposition is complex and involves the breakdown of soft tissue ...

Chemoselectivity

Chemoselectivity is the preferential outcome of a chemical reaction over a set of possible alternative reactions. In another definition, chemoselectivity refers to the selective reactivity of one functional group in the presence of others; often ...

Chichibabin reaction

The Chichibabin reaction -chē-bā-bēn) is a method for producing 2-aminopyridine derivatives by the reaction of pyridine with sodium amide. It was reported by Aleksei Chichibabin in 1914. The following is the overall form of the general reaction: ...

Coherent control

Coherent control is a quantum mechanics-based method for controlling dynamical processes by light. The basic principle is to control quantum interference phenomena, typically by shaping the phase of laser pulses. The basic ideas have proliferated ...

Collision theory

Collision theory states that when suitable particles of the reactant hit each other, only a certain fraction of the collisions cause any noticeable or significant chemical change; these successful changes are called successful collisions. The suc ...

Color reaction

In chemistry, a color reaction or colour reaction is a chemical reaction that is used to transform colorless chemical compounds into colored derivatives which can be detected visually or with the aid of a colorimeter. The concentration of a color ...

Colorimetric analysis

Colorimetric analysis is a method of determining the concentration of a chemical element or chemical compound in a solution with the aid of a color reagent. It is applicable to both organic compounds and inorganic compounds and may be used with o ...

Combination reaction

A combination reaction is a reaction where two or more elements or compounds combine to form a single compound. Such reactions may be represented by equations of the following form: X + Y → XY. The combination of two or more elements and form one ...

Combustion

Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion doesnt always res ...

Comproportionation

Comproportionation or synproportionation is a chemical reaction where two reactants, each containing the same element but with a different oxidation number, form a product in which the elements involved reach the same oxidation number. It is oppo ...

Copper–chlorine cycle

The copper–chlorine cycle is a four-step thermochemical cycle for the production of hydrogen. The Cu–Cl cycle is a hybrid process that employs both thermochemical and electrolysis steps. It has a maximum temperature requirement of about 530 degre ...

Corey–Link reaction

In organic chemistry, the Corey–Link reaction is a name reaction that converts a 1.1.1-tricholoro-2-keto structure into a 2-aminocarboxylic acid or other acyl functional group with control of the chirality at the alpha position. The reaction is n ...

Coupled substitution

Coupled substitution is the geological process by which two elements simultaneous substitute into a crystal in order to maintain overall electrical neutrality and keep the charge constant. In forming a solid solution series, ionic size is more im ...

Cross-reactivity

Cross-reactivity, in a general sense, is the reactivity of an observed agent which initiates reactions outside the main reaction expected. In immunology, the cross-reactivity has a more narrow meaning of the reaction between an antibody and an an ...

Cyanation

In organic synthesis, cyanation is the attachment or substitution of a cyanide group on various substrates. Such transformations are high-value because they generate C-C bond. Furthermore nitriles are versatile functional groups.

Cyanoethylation

Cyanethylation is a nucleophilic addition reaction. A molecule of acrylonitrile is added to a nucleophile, for example an alcohol, thiol or an amine. Y H + H 2 C = C H − C N ⟶ Y − C H 2 − C H 2 − C N {\displaystyle \mathrm {YH+H_{2}C{=}CH{-}CN\lo ...