Quadrupole pattern

Lowering the temperature has a similar effect on the deuterium spectra as does increased loadings. In Figure 3, spectra for benzene-d6/(Na)X at 0.7 molecules/supercage over the temperature range 298 to 133 K are shown. It is observed that both benzene species are detected simultaneously between 228 and 188 K. Below this temperature the oriented benzene species becomes the predominant form. A similar situation occurs for polycrystalline benzene-dg in which two quadrupole patterns, one static and the other motionally narrowed due to C rotation, are observed to coexist at temperatures between 110 and 130 K (7). This behavior has been attributed to sample imperfections (8) which give rise to a narrow distribution in correlation times for reorientation about the hexad axis. For benzene in (Na)X and (Cs,Na)X such imperfections may result from the ion/benzene interaction, and a nonuniform distribution of benzene molecules and ions within the zeolite. These factors may also be responsible for producing the individual species. However, from the NMR spectra it is not possible to... 

Fig. 7.32 Mossbauer spectra of (i) ruthenium red, [Ru302(NH3)i4]Cl6 and (ii) ruthenium brown, [Ru302(NH3)i4]Cl7, fitted with a side-by-side (a) and an overlapping (b) arrangement of two quadrupole patterns (from [116])...

Two superimposed quadrupole patterns with large and small A respectively have been observed in pressure-dependence studies [22]. Interpretation was in terms of spin excitation from 5 = 1 to 5 = 2 states, but the possibility of a phase change has not been eliminated. 

Fig. 11. Quadrupole hyperfine spectrum of Np in Np metal. The bar diagram shows the decomposition into two quadrupole patterns meaning that Np occupies two lattice sites with different local symmetries. In both cases the electric field gradient is not rotationally symmetric (rj 0). The fit (solid line) includes the Goldanskii-Karyagin effect (see text). The dashed line shows the spectrum expected in case of full isotropy. [Taken from Dunlap et al. (1970).]...

Ho is not a practical Mossbauer isotope, thus Mossbauer spectroscopy is restricted to Fe. Some spectra are shown in fig. 51. At high temperatures one observes a pure quadrupole pattern (two lines) below 175 K an additional magnetic pattern... 

The effectiveness of strike-slip faults in generating tsunamis relative to dip-slip faults has recently been debated. Although the slip vector is parallel to the surface, there is vertical displacement associated with strike-slip faults, occurring in a quadrupole pattern (see also Fig. 2b). Using a dislocation model, the vertical displacement pattern for dip-slip and strike-slip faults is compared in Fig. 2 for the same amount of slip and depth to the up-dip edge of the dislocation. For this case, the maximum vertical... 

Molecular motion of PDES in the liquid crystalline phase. In the observed spectra of PDES in the biphasic (mainly LC) phase, the typical quadrupole pattern of the signal disappears as a result of fast uniaxial molecular rotation... 

Figure 1 shows a positive static SIMS spectrum (obtained using a quadrupole) for polyethylene over the mass range 0—200 amu. The data are plotted as secondary ion intensity on a linear y-axis as a function of their chaige-to-mass ratios (amu). This spectrum can be compared to a similar analysis from polystyrene seen in Figure 2. One can note easily the differences in fragmentation patterns between the...

Fig. 4.14 Magnetically perturbed quadrupole spectra simulated for powder distributions of the EFG (Vzz > 0) with an applied field B = 4T which is fixed in the laboratory system perpendicular to the y-beam/ The value of the quadrupole splitting is kept constant at AEq = +4 mm s For negative quadrupole splitting (V z < 0), the spectra would be inverted on the velocity scale. Note the difference in relative intensities for the spectrum for ry = 0 and the single-crystal type spectrum given in Fig. 4.13. Similar patterns are obtained for B y...

In general, the mass resolution required for most analyses is such that the singly charged isotope patterns of the detected ions are readily discernible. For applications involving molecular weights up to about 1500 Da, this can be provided by magnetic sector, quadrupole, and time-of-flight mass spectrometers. 

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