Iodine quadrupole splitting

Relationship between Isomer Shift and Quadrupole Splitting in Some Iodine Compounds... 

Stable bonds are not always formed during the /3-decay. A source of showed only a single-line resonance without any quadrupole splitting. Apparently atomic xenon is formed which does not interact with the immediate neighbour undecayed iodine whose chemical state is unknown [119]. 

Polyvinylferrocene, 14, polyferrocenylene, 15, and polyethynylferro-cene, 16, were each oxidized by dichlorodicyanoquinone (DDQ), iodine, and TCNQ to give a polymer series e.g. Equations 1, 2, and 3) with a range of Fe(II)/Fe(III) ratios. The amount of oxidation was controlled by the reactant stoichiometry, and Fe(II)/Fe(III) ratios were firmly established by both elemental analyses and by Mossbauer spectroscopy (21). In each case, the isomer shifts and quadrupole splittings were about 0.78 and 0.0-0.2 for ferricenium units. Each DDQ molecule incorporated into the polysalts was reduced to DDQ" as was indicated by the absence of the 1680 cm" vco of DDQ and the presence of the 1590 cm" vco of DDQ" (21). The Fe(II)/Fe(III) ratios from elemental analyses agreed within 5% with those determined by Mossbauer spectroscopy. All mixed valence polymers were blue-black or black because of the ferricenium 620 nm 2 / transition. Polysalts of 15... 

It is cleaur, however, that these two parauneters measure very different types of bond polarity. The isomer shift is correlated with electronegativity and places the orgamic groups between iodine and bromine. Quadrupole splitting, on the other hauid, can be correlated with Taft a -values amd places the orgauiic groups and the halogens at opposite extremes of the... 

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.)... 

Results obtained from the alkali iodides on the isomer shift, the NMR chemical shift and its pressure dependence, and dynamic quadrupole coupling are compared. These results are discussed in terms of shielding by the 5p electrons and of Lbwdins technique of symmetrical orthogonalization which takes into account the distortion of the free ion functions by overlap. The recoilless fractions for all the alkali iodides are approximately constant at 80°K. Recent results include hybridization effects inferred from the isomer shifts of the iodates and the periodates, magnetic and electric quadrupole hyperfine splittings, and results obtained from molecular iodine and other iodine compounds. The properties of the 57.6-k.e.v. transition of 1 and the 27.7-k.e.v. transition of 1 are compared. 

Three zf ODMR transitions of triplet IIN are observed at frequencies of 601, 3435, and 4038 MHz and are shown under high-resolution conditions in Fig. 3A-C. Immediately apparent from these spectra is the splitting of two of the three transitions in zf the 601 MHz transition shows a partially resolved feature on the high-frequency side and the 3435 MHz transition shows a well-resolved feature on the low-frequency side. This structure arises from the iodine hyperfine interaction (see below) and is not observed in the 4038 MHz transition although it is somewhat broader than the resolved components of the two lower-frequency transitions. The 3435 MHz transition is most intense and exhibits six forbidden quadrupole satellites at high microwave power as shown in Fig. 3F. For the 601 MHz transition sufficient... 

---