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Molecular promiscuity

Molecular promiscuity indicates the ability of a molecule to bind to interact with one or more other classes and subtypes of molecules, in synergistic or antagonistic ways. These interactions may involve multiple paracrine, endocrine and autocrin ...

Molecularity

Molecularity in chemistry is the number of molecules that come together to react in an elementary reaction and is equal to the sum of stoichiometric coefficients of reactants in this elementary reaction. Depending on how many molecules come toget ...

Neutralization (chemistry)

In chemistry, neutralization or neutralisation is a chemical reaction in which an acid and a base react quantitatively with each other. In a reaction in water, neutralization results in there being no excess of hydrogen or hydroxide ions present ...

Nitrolysis

Nitrolysis is a chemical reaction involving cleavage of a chemical bond concomitant with installation of a nitro group. Typical reagents for effecting this conversion are nitric acid and acetyl nitrate. A commercially important nitrolysis reactio ...

Nitrosylation

Nitrosylation is the general term for covalent incorporation of a nitric oxide "nitrosyl" moiety into another molecule. There are multiple chemical mechanisms by which this can be achieved; including biological enzymes and industrial processes. T ...

S-Nitrosylation

S-Nitrosylation is the covalent attachment of a nitric oxide group to cysteine thiol within a protein to form an S -nitrosothiol. S-nitrosylation has diverse regulatory roles in bacteria, yeast and plants and in all mammalian cells. It thus opera ...

Nucleophilic acyl substitution

Nucleophilic acyl substitution describe a class of substitution reactions involving nucleophiles and acyl compounds. In this type of reaction, a nucleophile – such as an alcohol, amine, or enolate – displaces the leaving group of an acyl derivati ...

Nucleophilic addition

In organic chemistry, a nucleophilic addition reaction is an addition reaction where a chemical compound with an electron-deficient or electrophilic double or triple bond, a π bond, reacts with electron-rich reactant, termed a nucleophile, with d ...

Nucleophilic aromatic substitution

A nucleophilic aromatic substitution is a substitution reaction in organic chemistry in which the nucleophile displaces a good leaving group, such as a halide, on an aromatic ring. There are 6 nucleophilic substitution mechanisms encountered with ...

Nucleophilic substitution

In organic chemistry and inorganic chemistry, nucleophilic substitution is a fundamental class of reactions in which an electron rich nucleophile selectively bonds with or attacks the positive or partially positive charge of an atom or a group of ...

Old Nassau reaction

The Old Nassau reaction or Halloween reaction is a chemical clock reaction in which a clear solution turns orange and then black. This reaction was discovered by two undergraduate students at Princeton University researching the inhibition of the ...

Oxidative addition

Oxidative addition and reductive elimination are two important and related classes of reactions in organometallic chemistry. Oxidative addition is a process that increases both the oxidation state and coordination number of a metal centre. Oxidat ...

Oxidative carbonylation

Oxidative carbonylation is a class of reactions that use carbon monoxide in combination with an oxidant to generate esters and carbonate esters. These transformations utilize transition metal complexes as homogeneous catalysts. Many of these reac ...

Oxidative coupling

Oxidative coupling in chemistry is a coupling reaction of two molecular entities through an oxidative process. Usually oxidative couplings are catalysed by a transition metal complex like in classical cross-coupling reactions, although the underl ...

Oxidative coupling of methane

The oxidative coupling of methane is a type of chemical reaction discovered in the 1980s for the direct conversion of natural gas, primarily consisting of methane, into value-added chemicals.

Oxidative dissolution of silver nanoparticles

Silver nanoparticles act primarily through a process known as oxidative dissolution, wherein Ag+ ions are released through an oxidative mechanism. AgNPs have potentially vast applications within the fields of medicine, science, and food and drug ...

Partial oxidation

Partial oxidation is a type of chemical reaction. It occurs when a substoichiometric fuel-air mixture is partially combusted in a reformer, creating a hydrogen-rich syngas which can then be put to further use, for example in a fuel cell. A distin ...

Peters four-step chemistry

Peters four-step chemistry is a systematically reduced mechanism for methane combustion, named after Norbert Peters, who derived it in 1985. The mechanism reads as CH 4 + 2 H + H 2 O → I CO + 4 H 2 {\displaystyle {\ce {CH4 + 2H + H2O -> 2H + 2 ...

Photochlorination

Photochlorination is a chemical reaction which is initiated by light, in which either hydrogen is replaced by chlorine in a hydrocarbon compound or chlorine is reacted via an addition reaction to an aromatic or olefinic hydrocarbon. Photochlorina ...

Photodissociation

Photodissociation, photolysis, or photodecomposition is a chemical reaction in which a chemical compound is broken down by photons. It is defined as the interaction of one or more photons with one target molecule. Photodissociation is not limited ...

Photoelectrochemical process

Photoelectrochemical processes are processes in photoelectrochemistry; they usually involve transforming light into other forms of energy. These processes apply to photochemistry, optically pumped lasers, sensitized solar cells, luminescence, and ...

Photoinduced electron transfer

Photoinduced electron transfer is an excited state electron transfer process by which an excited electron is transferred from donor to acceptor. Due to PET a charge separation is generated, i.e., redox reaction takes place in excited state.

Photoisomerization

In chemistry, photoisomerization is a form of isomerization induced by photoexcitation. Both reversible and irreversible photoisomerizations are known. The term "photoisomerization" usually, however, refers to a reversible process.

Potentiator

In clinical terms, a potentiator is a reagent that enhances sensitization of an antigen. Potentiators are used in the clinical laboratory for performing blood banking procedures that require enhancement of agglutination to detect the presence of ...

Product (chemistry)

Products are the species formed from chemical reactions. During a chemical reaction reactants are transformed into products after passing through a high energy transition state. This process results in the consumption of the reactants. It can be ...

Product-determining step

The product-determining step is the step of a chemical reaction that determines the ratio of products formed via differing reaction mechanisms that start from the same reactants. The product determining step is not rate limiting if the rate limit ...

Protodeboronation

Protodeboronation, or protodeborylation is a chemical reaction involving the protonolysis of a boronic acid in which a carbon-boron bond is broken and replaced with a carbon-hydrogen bond. Protodeboronation is a well-known undesired side reaction ...

Protonation

In chemistry, protonation is the addition of a hydrogen ion, an isotopes of hydrogen to an atom, molecule, or ion, forming the conjugate acid. Some examples include the protonation of isobutene in the formation of a carbocation: CH 3 2 C=CH 2 + H ...

Protonolysis

Protonolysis is the cleavage of a chemical bond by acids. Many examples are found in organometallic chemistry since the reaction requires polar M δ+ -R δ- bonds, where δ+ and δ- signify partial positive and negative charges associated with the bo ...

PROX

PROX is an acronym for PReferential OXidation, and refers to the preferential oxidation of a gas on a catalyst. The catalyst preferentially oxidises carbon monoxide CO using a heterogeneous catalyst placed upon a ceramic support. Catalysts includ ...

Racemization

In chemistry, racemization is a conversion, by heat or by chemical reaction, of an optically active compound into an optically inactive form which half of the optically active substance becomes its mirror image referred as racemic mixtures and fo ...

Radiolysis

Radiolysis is the dissociation of molecules by ionizing radiation. It is the cleavage of one or several chemical bonds resulting from exposure to high-energy flux. The radiation in this context is associated with ionizing radiation; radiolysis is ...

Rate equation

The rate law or rate equation for a chemical reaction is an equation that links the reaction rate with the concentrations or pressures of the reactants and constant parameters. For many reactions the rate is given by a power law such as v = k exp ...

Rate-determining step

In chemical kinetics, the overall rate of a reaction is often approximately determined by the slowest step, known as the rate-determining step or rate-limiting step. For a given reaction mechanism, the prediction of the corresponding rate equatio ...

Reaction intermediate

A reaction intermediate or an intermediate is a molecular entity that is formed from the reactants and reacts further to give the directly observed products of a chemical reaction. Most chemical reactions are stepwise, that is they take more than ...

Reagent

A reagent is a substance or compound added to a system to cause a chemical reaction, or added to test if a reaction occurs. The terms reactant and reagent are often used interchangeably - however, a reactant is more specifically a substance consu ...

Redistribution (chemistry)

In chemistry, redistribution usually refers to the exchange of anionic ligands bonded to metal and metalloid centers. The conversion does not involve redox, in contrast to disproportionation reactions. Some useful redistribution reactions are con ...

Redox

Redox is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the transfer of electrons between chemical species, most often with one species undergoing oxidation while another speci ...

Reducing agent

Reducing agent is an element or compound that loses an electron to an electron recipient in a redox chemical reaction. A reducing agent is thus oxidized when it loses electrons in the redox reaction. Reducing agents "reduce" or, are "oxidized" by ...

Reductive elimination

Reductive elimination is an elementary step in organometallic chemistry in which the oxidation state of the metal center decreases while forming a new covalent bond between two ligands. It is the microscopic reverse of oxidative addition, and is ...

Retarder (chemistry)

A retarder is a chemical agent that slows down a chemical reaction. For example, retarders are used to slow the chemical reaction hardening of plastic materials such as wallboard, concrete, and adhesives. Sugar water acts as a retarder for the cu ...

Ring forming reaction

A ring forming reaction or ring-closing reaction in organic chemistry is a general term for a variety of reactions that introduce one or more rings into a molecule. A heterocycle forming reaction is such a reaction that introduces a new heterocyc ...

Roskamp reaction

The Roskamp reaction was first discovered by Eric J. Roskamp and co-workers in 1989. This reaction is very useful in synthesizing β-keto esters from aldehydes and diazoacetate, using various Lewis acids as catalysts. The two most noteworthy aspec ...

S-acylation

S-acylation is the process of chemically linking a molecule to another molecule via a thioester bond. Protein S-acylation is a sub-type of S-acylation where the first of those molecules is a protein, and connected to the second through a cysteine ...

Salt metathesis reaction

Reaction in which two compounds in their aqueous solution react to form two new product by interchanging their radicals or ions is called a double decomposition reaction or double displacement reaction A-B + C-D → A-D + C-B The bond between the r ...

Scavenger resin

Scavenger resins are polymers with bound functional groups that react with specific by-products, impurities, or excess reagents produced in a reaction. Polymer-bound functional groups permit the use of many different scavengers, as the functional ...

Screaming jelly babies

Screaming jelly babies ", also known as Growling gummy bears ", is a classroom chemistry demonstration, variants of which are practised in schools around the world. It is often used at open evenings to demonstrate the more light-hearted side of s ...

SEA Native Peptide Ligation

Protein chemical synthesis by native peptide ligation of unprotected peptide segments is an interesting complement and potential alternative to the use of living systems for producing proteins. The synthesis of proteins requires efficient native ...

Self-assembling peptide

Self-assembling peptides are a category of peptides which undergo spontaneous assembling into ordered nanostructures. Originally described in 1993, these designer peptides have attracted interest in the field of nanotechnology for their potential ...

Semiclassical transition state theory

Semiclassical Transition State Theory is an efficient chemical rate theory, which aims to calculate accurate rate constants of chemical reactions, including nuclear quantum effects such as tunnelling, from ab initio quantum chemistry. The method ...