Doublet separation

L3M45M4 5 would often appear as L3M2,3V and L3W, respectively, and similarly 1 2,3 4,5 4,51 as M2,3W. In Fig. 2.22 the increase in the intensity of the L3W peak relative to the other two, upon going from chromium to iron, is because of the progressive increase in the electron density in the valence band. The characteristic doublet seen in the MNN series arises from the M4 5N4,sN4,5 transitions, in which the doublet separation is that of the core levels M4 and M5. 

Fig. 21. Schematic illustration of MP-HNCA-TROSY antiphase (a) and in-phase (b) spectra with long acquisition time in q. The corresponding subspectra are shown after addition of the antiphase and in-phase data sets (c) and after subtraction of the antiphase and in-phase data sets (d). Due to very small Vcc > the intraresidual cross peaks are almost entirely cancelled out from the antiphase spectrum (a). In the subspectra, the intraresidual cross peaks are shown as doublets, separated by 53 Hz splitting in Fi-dimension, whereas sequential cross peaks are shown as singlets, and they exhibit 53 Hz offset for the upheld and downfield components between the subspectra.

Disregarding the actual amount of this doublet separation, it is important to note that the presence of this doublet, rather than a singlet, at temperatures... 

The quantum version of the Hamiltonian Eq. (7) has been studied for decades in both Physics and Chemistry in the 2-level limit. If the potential energy surface (PES) is represented as a quartic double well, then the energy eigenvalues are doublets separated by, roughly, the well frequency. When the mass of the transferred particle is small (e g. electron), or the barrier is very high, or the temperature is low, then only the lowest doublet is occupied this is the 2-level limit of the Zwanzig Hamiltonian. 

The Lorentzian shape of x-ray emission lines is well founded in quantum theory and has been substantiated experimentally (Hoyt, 1932). Siegbahn et al. (1967) discuss the aluminum anode x-ray source as applied to ESCA. Beatham and Orchard (1976) list doublet separations and half-widths derived from the literature and optimized by computer simulation. Kallne and Aberg (1975) and Senemaud (1968) also provide values. 

The [2AP]A GGAi2- and [2AP]T GGTi2- oligonucleotides containing a single 2AP residue and a single GG doublet separated only by adenine (n=0, 2, 4, 6, 8) or thymine (n=0, 1, 2, 3, 4) bases were used to study base sequence effects on electron transfer at a distance. The [2AP]Ai4 and [2AP]Ti4 oligonucleotides were used as controls. All of the duplexes exhibit well-defined... 

Table I. The energy levels (E) and the doublet separation for the fundamental and the first over-tone as a function of q...

A curve is constructed, in which the theoretical doublet separation is plotted against von. However, it must be pointed out that in the case of very short H-bonds, the circumstances are very complicated and the curve is no more valid. 

It can be seen that the doublet separation increases and the height of the potential hill decreases rapidly with decreasing of the bridge length or v0H, With very short hydrogen bonds, the central potential hill between the two minima is almost perfectly flattened out. 

Exercise 19-5 When optically active 1-phenylethanamine is dissolved in racemic 1-phenyl-2,2,2-trifluoroethanol, the 19F nmr resonance shows two sets of doublets separated by 2 Hz at 56 MHz. With the racemic amine, only a doublet 19F resonance is observed. 

By inserting a hypodermic needle through the O-ring seal, this equipment was adapted to reverse osmosis experiments by using a cellophane doublet separated by a powder gap in place of the single cellophane used by Richards [14). After some difficulty with the reliability of the pressure system, fresh water was produced at the rate of 0.06 gallon per square foot per day. 

The refocusing delay just before acquisition has been eliminated, so the peaks in F2 will be antiphase doublets separated by the long-range/cH (2-15 Hz). This splitting is in addition to any H splitting pattern already present in the ID proton spectrum (Fig. 11.11). The second 13 C 90° pulse is phase cycled as before to make sure that only H magnetization... 

Fig. 1 indicates which transitions may be observed in microwave, infrared and Raman spectroscopy. The line frequencies and doublet separations are related to the tunneling frequency. 

Monomeric 2,4,6-tri-t-butylphenyllithium 20 provided unusual insights into the nature of 7 Li relaxation. Schleyer and coworkers reported NMR data on 20 in THF with PMDTA. At 193 K, the 13C NMR spectrum of Li bound carbon consisted of two resonances, a broad doublet, separation 70 Hz due to 13C—7Li overlaid by a cleanly resolved triplet due to the 20-6Li isotopomer (6Li in natural abundance) with. /(I3C, 6Li) of 16 Hz, the signature for... 

The EPR spectrum [17] confirms this conclusion - showing the anisotropic low-spin signal exclusively (g = 2.014, g = 2.256 see the 77K-spectrum of Cs2KNiF6 in Fig. 3 for comparison), even up to 298 K. The deviation of g from the spin-only value ((5g = 0.012) allows an estimation of the quartet-doublet separation energy for large values the following equation is valid ... 

Proceeding to nitrogen as the ligator atom, one usually observes a spin-flip from t2g eg to t2g, though thorough studies are scarce [42], small spin sextet-to-doublet separation energies can be suggested (vide infra). We refrain to go into details, because the cross-over is only weakly influenced by JT forces. 

Tb (Did) ground orbital doublet separated by A = 2.2 cm" from the first excited singlet... 

The AB part of the ABX spectrum is made up of two overlapping quartets (Figure A4-3). The doublet separation between the first and second and between the third and fourth peaks in both quartets gives four independent measurements of 7ab- (No absolute or relative information about the sign is obtained.) The separation of alternate peaks (first and third or second and fourth) provides redundant determinations of D+ and D. The separation of the midpoints of the two quartets gives an additional measurement of 2 (Ax Ax) of these spacings are illustrated in the figure. 

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