Hyperline interactions

Santos JG, Silveira LB, Oliveira AC, Garg VK, Lacava BM, Tedesco AC, Morais PC (2007) Hyperline Interact 175 71... 

The number of isotropic hyperfine lines from a particular nucleus depends on the nuclear spin, I, and the line multiplicity is 2/ + 1. For n equivalent nuclei, the EPR spectrum consists of 2nl + 1 lines whose relative intensities are given by binomial coefficients obtained in the expansion of (1 + x)n (Knowles et al., 1976). When nuclear hyperline interactions occur, Eq. (16.4) becomes... 

For each of the alkali metals used the e.s.r. spectrum at 77°K consisted of a single narrow line (Fig. 12a, b). The relevant features of the e.s.r. spectra are summarized in Table 4. The absence of any effect of the cation on the line width or p-factors shows conclusively that the electron has been transferred completely from the alkali metal atom and is therefore not held in an expanded orbital around the cation, as suggested by Jortner and Sharf (1962). The difference in line width between the spectra in D2O (3-2 G) and in water (9-2 G) suggests that there is a hyperline interaction between the electron and the protons in water. This was shown conclusively by the observation of seven equally spaced hyperfine lines when a deposit prepared from water was warmed carefully (Fig. 12c), whereas no hyperfine structure was observed from a sample containing deuterium oxide. The hyperfine structure shows that the electron interacts primarily with six protons and that it is not delocalized over a large number of water molecules but is located in a well-defined trap surrounded by these protons. 

The effects of the hyperline interaction on NMR properties of nuclei can be exploited to obtain information on molecular structure beyond what is available using traditional restraints such as NOEs and coupling constants. 

Let us consider the simple case of no hyperline interaction, A = 0 (Fig. 2b). A transition is induced by the microwave field when its angular frequency a> equals the Larmor frequency two(w) = ( 1/2 —... 

Nuclear forward scattering (NFS) allows to study hyperline interactions, as obtained with conventional Mossbauer spectroscopy nuclear inelastic scattering (NIS) allows to investigate local phonon spectra (partial density of states, PDOS) at the Mossbauer probe nucleus. Compared, for instance, to Raman spectroscopy, NIS can achieve a higher resolution without perturbation of surrounding vibrations. Both synchrotron radiation techniques, NFS and NIS, are certainly on then-way to a great future. 

In case of Fe, the resonant absorption of 14.4 keV y-rays emitted by a radioactive Co source is measured. The spectra are determined by the hyperfine interactions (isomer shift, quadrupole splitting, and magnetic hyperline field) of the Mossbauer nucleus caused by the surrounding electron shell. 

DPPH = 2,2-diphenyl-l-picrylhydrazyl ENDOR= electron-nuclear double resonance EPR = electron paramagnetic resonance ESE = electron spin echoes ESEEM = electron spin echo envelope modulation FFT = fast fourier transformations FWHM = full width at half maximum HYSCORE = hyperline sublevel correlation nqi = nuclear quadrupole interaction TauD = taurine/aKG dioxygenase TWTA = traveling wave tube amplifier ZFS = zero field splitting. 

Magnetic tuning of diatomic bound-state and scattering properties relies on the Zee-man effect in the hyperline structure of alkali-metal atoms. The splitting into sublevels of the 5i/2 electronic ground state of such an atom which is exposed to a magnetic field B can be described by the following Hamiltonian comprised of hyperfine and Zeeman interactions [27] ... 

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