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Isotopomers or isotopic isomers are isomers with isotopic atoms, having the same number of each isotope of each element but differing in their positions in the molecule. The result is that the molecules are either constitutional isomers or stereoisomers solely based on isotopic location.
The isomeric shift on atomic spectral lines is the energy or frequency shift in atomic spectra, which occurs when one replaces one nuclear isomer by another. The effect was predicted by Richard M. Weiner [2] in 1956, whose calculations showed that it should be measurable by atomic (optical) spectroscopy (see also [3]).
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.
The term isotopes (originally also isotopic elements, [4] now sometimes isotopic nuclides [5]) is intended to imply comparison (like synonyms or isomers). For example, the nuclides 12 6 C, 13 6 C, 14 6 C are isotopes (nuclides with the same atomic number but different mass numbers [6]), but 40 18 Ar, 40 19 K, 40 20 Ca are isobars (nuclides with ...
The mass difference (mass shift), which dominates the isotope shift of light elements. [2] It is traditionally divided to a normal mass shift (NMS) resulting from the change in the reduced electronic mass, and a specific mass shift (SMS), which is present in multi-electron atoms and ions.
A chart or table of nuclides maps the nuclear, or radioactive, behavior of nuclides, as it distinguishes the isotopes of an element.It contrasts with a periodic table, which only maps their chemical behavior, since isotopes (nuclides that are variants of the same element) do not differ chemically to any significant degree, with the exception of hydrogen.
There are 28 known radioisotopes and 8 nuclear isomers, the most stable of which are 60 Fe (half-life 2.6 million years) and 55 Fe (half-life 2.7 years). Much of the past work on measuring the isotopic composition of iron has centered on determining 60 Fe variations due to processes accompanying nucleosynthesis (i.e., meteorite studies) and ore ...
The alcohol "3-propanol" is not another isomer, since the difference between it and 1-propanol is not real; it is only the result of an arbitrary choice in the direction of numbering the carbons along the chain. For the same reason, "ethoxymethane" is the same molecule as methoxyethane, not another isomer.