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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 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 ...
Deuterium (hydrogen-2, symbol 2 H or D, also known as heavy hydrogen) is one of two stable isotopes of hydrogen; the other is protium, or hydrogen-1, 1 H. The deuterium nucleus (deuteron) contains one proton and one neutron, whereas the far more common 1 H has no neutrons. The name deuterium comes from Greek deuteros, meaning "second".
Hydrogen is the only element whose isotopes have different names that remain in common use today: 2 H is deuterium [6] and 3 H is tritium. [7] The symbols D and T are sometimes used for deuterium and tritium; IUPAC ( International Union of Pure and Applied Chemistry ) accepts said symbols, but recommends the standard isotopic symbols 2 H and 3 ...
Isotopic shifts are best known and most widely used in vibration spectroscopy, where the shifts are large, being proportional to the ratio of the square root of the isotopic masses. In the case of hydrogen, the "H-D shift" is (1/2) 1/2 ≈ 1/1.41. Thus, the (totally symmetric) C−H and C−D vibrations for CH 4 and CD
However only certain ratios are possible in mixture, due to prevalent hydrogen swapping. The atom(s) of the different isotope may be anywhere in a molecule, so the difference is in the net chemical formula. If a compound has several atoms of the same element, any one of them could be the altered one, and it would still be the same isotopologue.