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Hydrogen–deuterium exchange (also called H–D or H/D exchange) is a chemical reaction in which a covalently bonded hydrogen atom is replaced by a deuterium atom, or vice versa. It can be applied most easily to exchangeable protons and deuterons, where such a transformation occurs in the presence of a suitable deuterium source, without any ...
Almost all the organic hydrogen is exchangeable to some extent. Isotopic exchange of organic hydrogen will reorder the distribution of deuterium and often incorporate external hydrogen. Generally, more mature materials are more heavily exchanged. With effective exchange, aliphatic hydrogen can finally reach isotopic equilibrium at the final stage.
The deuterium bottleneck in the formation of helium, together with the lack of stable ways for helium to combine with hydrogen or with itself (no stable nucleus has a mass number of 5 or 8) meant that an insignificant amount of carbon, or any elements heavier than carbon, formed in the Big Bang.
A primary kinetic isotope effect (PKIE) may be found when a bond to the isotopically labeled atom is being formed or broken. [3] [4]: 427 Depending on the way a KIE is probed (parallel measurement of rates vs. intermolecular competition vs. intramolecular competition), the observation of a PKIE is indicative of breaking/forming a bond to the isotope at the rate-limiting step, or subsequent ...
Upon adding phenol to deuterated water (water containing D 2 O in addition to the usual H 2 O), a hydrogen-deuterium exchange is observed to affect phenol's hydroxyl group (resulting in C 6 H 5 OD), indicating that phenol readily undergoes hydrogen-exchange reactions with water. Mainly the hydroxyl group is affected—without a catalyst, the ...
The Shilov system was discovered by Alexander E. Shilov in 1969-1972 while investigating H/D exchange between isotopologues of CH 4 and H 2 O catalyzed simple transition metal coordination complexes. The Shilov cycle is the partial oxidation of a hydrocarbon to an alcohol or alcohol precursor (RCl) catalyzed by Pt II Cl 2 in an aqueous solution ...
The absolute abundance of each isotopologue primarily depends on the traditional carbon and hydrogen isotope compositions (δ 13 C and δD) of the molecules. Clumped isotope composition is calculated relative to the random distribution of carbon and hydrogen isotopes in the methane molecules. The deviations from the random distribution is the ...
Deuterated acetone ((CD 3) 2 CO), also known as acetone-d 6, is a form (isotopologue) of acetone (CH 3) 2 CO in which the hydrogen atom (H) is replaced with deuterium (heavy hydrogen) isotope (2 H or D). Deuterated acetone is a common solvent used in NMR spectroscopy. [1]