Fermi doublets

The 0 3 connection has a chiral component that seems to imply that Ti v has a chiral component, or is mixed with the chiral component of the other SU(2) chiral field of the electroweak theory. This is what happens to SU(2) electromagnetism at very high energies. It becomes very similar in formal structure to the theory of weak interactions and has implications for the theory of leptons. The electromagnetic interaction acts on a doublet that can be treated as an element of a Fermi doublet of charged leptons and their neutrinos in the SU(2) theory of the weak interaction. 

Shurvell175 and collaborators have published the Raman and IR spectra of tetramethylcyclobutane-l-one-3-thione and the fully deuterated derivative. For this compound, the C=0 stretching was observed as a very strong Fermi doublet at 1811-1782 cm-1. For the deuterated species this doublet is red-shifted and was found at 1808-1775 cm-1. The C=S stretching mode was assigned to a band of medium intensity at 1303 cm-1 and 1302 cm-1 in the IR and Raman spectra, respectively, and the same for the deuterated species are found at 1306 cm-1 and 1309 cm-1, respectively. 

In their initial studies, Tfayli et al. [33] acquired spectra from an Episkin model. This model is comprised of human adult keratinocytes which produce stratified epidermis following a 13 h culture period. Raman spectra from this model were compared with normal human skin. Significant differences were noted, particularly in spectral features arising from the 850/830 tyr Fermi doublet (which is sensitive to the H-bonding state of the -OH group [34]) and in the protein amide III region. Usable spectra were acquired to a depth of 15-20 pm. 

The 27-cliads in the vibrational Raman spectrum of CO2 and its isotopic variants were measured and their intensity distribution simulated (Srinivasan et al., 1977 Finsterholzl et al., 1978 Kldckneret al., 1978 Finsterholzl, 1982 Wienecke et al., 1986). In Fig. 4.3-25 the experimental and the calculated Raman spectra of natural CO2 in the Fermi resonance region are presented, the lowest (calculated) spectrum showing only the 2-branches of the Fermi doublet of C 02 and its hot bands and those of the isotopomers C 02, and occuming in natural abundances of 1.1 %, 0.4 %, and 0.08 %,... 

Strong Fermi resonance occurs (13) in NH2 between the vibrational levels (0 10 0) and (16 0) and between the levels (0 12 0) and (1 8 0). The first of the above two Fermi doublets appears more sensitive to environmental perturbations than the latter. For example, the energy splitting between the two members of the lower doublet decreases steadily from 196 cm. i for vapor-phase NH2 to 168 cm. i for NH2 in xenon. For the higher doublet, the splitting remains essentially constant at 167 cmr This peculiar effect is not understood. It does indicate that the anharmonicities which give rise to the Fermi interaction are affected to some extent by the environment. 

Figure 7. Variation of measured relaxation rates 2F+ and 2F for D,. line ( —solid o—liquid) and n line ( —solid —liquid) of Fermi doublet in CO2. Dashed line indicates phase transition. Note scale change between liquid and solid. Full lines are calculated using a four-phonon relaxation mechanism.

IR and Raman bands due to vOH from Fe OH and A1 OH units were seen for the minerals cacoxenite and gormanite.334 Dioxygen reacted with recombinant human serum albumin incorporating Fen(TPP) to give v02 at 1158 cm 1 due to coordinated 02.335 The complex (61) forms an 02 adduct with vOO as a Fermi doublet at 877, 893 cm-1.336... 

The Fermi resonance effect usually leads to two bands appearing close together when only one is expected. When an overtone or a combination band have the same or a similar frequency to that of a fundamental, two bands appear, split either side of the expected value, which are of about equal intensity. This effect is greatest when the frequencies match, but it is also present when there is a mismatch of a few tens of wavenumbers. The two bands are referred to as a Fermi doublet. 

H = —2JSi-S2. Solid sample. Frozen solution sample. 4,4-Coordinate isomer. 5,5-Coordinate isomer. Fermi doublet. 

Bands other than those associated with pure internal tyrosyl vibrations have also been detected in both phosphatases Most notable among these are intense, polarized bands at 872, 805, 575, and 521 cm The pair of bands at 872 and 805 cm have been ascribed to a Fermi doublet, which are bands of coupled vibrations arising when an overtone of one vibration interacts with the fundamental of another vibration having the same symmetry Most probably, this Fermi resonance is between a tyrosyl ring breathing mode (v = 830 cm and an overtone of an out-of-plane bending mode of the same symmetry (vi a = 410 cm (nomenclature of Ref. 48 )). This assignment also implies resonance enhancement of the Vie, fundamental (the mode near 400 cm ) and recent low temperature Raman studies of both add phosphatases have detected a band at... 

Figure 23.8. Transmittance spectra of supercritical CO2 in a 1-cm-pathlength flow cell at 40°C and pressures between 900 psi (61 atm) and 2100 psi (142 atm). The intensification of the Fermi doublet near 1400 cm with increasing pressure should be noted. (Reproduced from [43], by permission of the American Chemical Society copyright 1986.)...

The optical spectra of Cu(III)(//-0)2Cu(III) complexes are unique with intense charge transfer bands at around 300 and 400 run. Resonance Raman studies on [(Cu(III)tacn )2(/i-oxo)2] found isotopicaUy sensitive bands at 602 and 612 cm that shifted to a single peak at 583 cm when the complex was prepared with 2. This isotopic shift is too small to be from a peroxo ligand but is consistent for a Cu-O vibration. The Cu-O vibration in the isotopomer is split into a Fermi doublet, giving rise to two observable peaks. Conclusive structural evidence was obtained from low-temperature XRD measurements that revealed Cu Cu and Cu-O distances of 2.794(2) and 1.81 A (Fig. 6.24) - these distances are significantly shorter than those found in complexes with Cu(ll)(y -OH)2Cu(II) or Cu(II)(,u- / / -00)Cu(II) cores. 

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