Chlorine-35 is a naturally occurring, stable isotope of the chemical element chlorine, which, in addition to the element-specific 17 protons, has 18 neutrons in the atomic nucleus, resulting in the mass number 35 ; the proportion of earthly chlorine is 75.8%. Isotopically pure 35Cl is obtained from conventional chlorine and is used, among other things, to produce Chlorine-36, a radioisotope that is used in research.
The nuclide 35Cl acts as a neutron absorber with a relatively high capture cross section for thermal neutrons of 44 barn. The natural chlorine isotope mixture of Cl-35 and Cl-36 (0.43 barn) still has a total neutron capture cross section of 33.45 barn.
See also: list of Chlorine isotopes.
Direct parent isotopes are: 35Ar, 35S, 36K.
|Atomic Mass ma||Quantity||Half-life||Spin|
|35.45 u||100 %|
|Isotope 36Cl||35.96830682(4) u|
|3.013(15) × 105 a||2+|
|Isotope 37Cl||36.9659026(4) u||24.2 %|
[23.9 - 24.5 %]
|Isotope 35Cl||34.9688527(3) u||75.80(17) %|
[75.5 - 76.1 %]
Nuclear magnetic properties of the NMR active Nuclide 35Cl
35Cl, along with 37Cl is one of the two natural chlorine isotopes that are suitable for NMR spectroscopy (36Cl only occurs in trace amounts and is radioactive). 35Cl-NMR spectroscopy is mainly used to investigate ionic and inorganic chlorides. In the spectra of organic chlorine compounds, the nucleus delivers very broad signals that become even broader with decreasing symmetry and the molecular size of the sample, which makes the use of this method in organic chemistry strongly limited.
Compared to the 37Cl nucleus, the 35Cl NMR is significantly more sensitive, but provides somewhat broader signals and shows a slightly worse resolution. The chemical shift range is between -50 and 1050 ppm.
|OZ||Isotone N = 18||Isobar A = 35|
Last update: 2023-12-05
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