Iodine nuclear parameters

There are several approaches to the use of NAA for iodine determination in foodstuffs and other biological materials. Of the two nuclear reactions of stable the reaction of T(n, ) I with thermal and epithermal neutrons is almost exclusively used, because favorable nuclear parameters (high activation cross-section and resonance integral for thermal and epithermal neutrons, respectively, cf. Table 2.3) provide much lower detection limits compared... 

The rotational dependence of the iodine nuclear quadrupole interaction, the aluminum spin-rotation coupling parameter (C(A1)), and the tensor iD a) as well as scalar ( ) spin-spin coupling constants have been determined for the first time, the remaining parameters (with the exception of D) have been improved in aeeuraey as compared to the literature values [73T6r, 72Wys]. 

As mentioned, the quadrupolar and magnetic shielding interactions are frequently the most important contributors to the total SSNMR spectrum of the quadrupolar halogens. Some calculations of indirect nuclear spin-spin coupling tensors involving chlorine, bromine, and iodine have been performed, particularly for gaseous diatomic molecules.However, we focus here on the parameters of current importance to the analysis of solid powdered samples (i.e. the EFG and a tensors). 

Table 2.3 Nuclear reactions and parameters of iodine radioisotopes used in neutron activation anaiysis...

In the case of nitrogen, whose nucleus has a spin 7=1, the situation is more favourable, as the experiment allows the determination of both the nuclear quadrupole coupling constant and the asymmetry parameter, and it is possible to make conclusions about sp hybridization, if the molecular geometry is known. However, the meaning of nuclear NQI for p electrons is not known with as much accuracy as for chlorine, bromine or iodine, but the estimation... 

The beta decay of in an iodine compound often leads to a xenon compound with the same ligands. The Mossbauer spectrum of the gamma radiation emitted from the Xe nuclei so formed shows hyperfine structure. This is due to the nuclear electric quadrupole moment eQ of the excited Xe nucleus, which results in a doublet absorption spectrum if the electric field gradient eq —d VIdz ) does not vanish. The observed quadrupole splitting equals e qQ 2 if the asymmetry parameter of the electric field gradient is negligible. (See Chapter 2.)... 

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