Isotope shifts listed

The six fundamental vibrational frequencies for SeF and TeFe are given in Table XII (21,37,38,103). Force constants for SeFs, calculated with the frequencies from vapor-phase Raman spectra (21) and using isotope shifts and Coriolis coupling constants as additional data (103), are listed in Table XIII in comparison to TeFg (1,24,104,125,139). 

Initially, ground-state geometry and vibrational frequencies were reported erroneously 7 . However, electronic, microwave, gas-phase infrared and matrix infrared spectra reported more recently turned out to be consistent with the ground-state parameters listed in Table 18. i>, and v3 at 850 cm-1 are perturbed by their close proximity and overlap, but the assignment has been supported by the observation of 29Si and 30Si isotopic shifts. v2 has been observed directly ° and been obtained from the microwave spectrum for the v=0 and v=l levels of v2. Furthermore the electronic transitions 4, - 1BI and 3fi, - lA3 exhibit a moderately pronounced progression with v2 = 343 cm-181-83 ... 

Cation bands, out-of-plane vibrational bands and combination-overtone bands are not listed. b Numbers in parentheses indicate 58Ni minus 62Ni isotope shifts, s = strong, m = medium, w = weak, and sh = shoulder. Data taken from (2). 

The table below lists all the NMR-active nuclei that appear in Chapters I 1-5, together with all their relevant properties. For a more complete listing, see Brevard and Granger. 6 Some nuclei, such as 180, have 1 = 0 and so are not NMR-active. However, they can sometimes be detected through the isotope shift that they induce in the resonances of nearby nuclei. 

In addition to the four strong infrared bands, table 1 lists five weak bands which also show the isotope shifts expected of pure carbon. There may also be more weaker bands. It is possible that these may also arise from the same C o molecule, but with its symmetry disturbed by the carbon impurity mass present in approximately 1% abundance. The disturbed symmetry may be causing some disallowed modes to become observable. Other symmetry distortions may occur by interaction of Ceo with the carbon grains. One may also speculate on the possibility that these additional bands are from the C70 molecule, which appears to a lesser extent in the mass spectra under conditions that produce a strong Cm peak [2]. 

Previously it was necessary to use N labelled samples in order to determine isotope shifts A N(X). By the application HEED extended pulse sequences,it proved possible to determine these parameters for numerous compounds in the natural abundance of (0.37%). Table 11 lists a number of these data and an example for the application of the HEED INEPT pulse sequence is shown in Fig. 9. 

The valence and symmetry force constants of benzene calculated using density functional theory were first reported by us [10c,d]. These results are summarized in this section. We discuss the vibrational frequencies (Table 5), isotopic shifts, and absorption intensities (Table 6). Selected force constants in symmetry-coordinate representations are listed and compared to the fields due to the Pulay [10b] et al. as well as OG [10a] in Table 7. 

There are several references where this information has been tabulated and reference to the original work may be found. Nuclear Spins and Moments by G. H. Fuller and V. W. Cohen, Nuclear Data Tables, 5,433 (1969) contains data for all the elements. A later compilation by S. Gerstenkorn, J. Physique, 34, 55 (1973) entitled Nuclear Properties Deduced from the Optical Spectra of the Atoms, Nuclear Moments and Isotope Shift of the Actinide and Rare Earth Series, lists the data through 1973. A report Table of Nuclear Moments by V. S. Shirley and C. M. Lederer, Lawrence Berkeley Laboratory, LBL-3450 (Dec. 1974) is a listing of all the elements. They have made corrections to the magnetic dipole moments based on a revised proton moment and have also corrected for diamagnetic shielding. 

In practice isotopic shifts in frequencies are usually a little less than 1/2. As an example of a molecule with two bends and one stretch sensitive to substitution, the vibration frequencies [14a] of CHCI3 and CDCI3 are listed in Table 1, and it is clear that the ratios ofisotopic... 

Moore s level list [8] is based on the results of van Kleef [2] who has found new levels in both parities, determined the g value of most of them and assigned tentative designations to a number of levels. As the studies of hyperfine structure and isotope shift and the theoretical calculations of the group of configurations (5d+6s) have led to the modification of some earlier designations, the lists of levels will be given (Tables 2/19 and 2/20, pp. 187/8). 

The structural picture is better clarified for the dichlorides (see Drake and Rosenblatt 1979 and references therein). Scandium dichloride is known to be linear (Dooh) as indicated by matrix IR isotope shifts and selection rules, while YCI2 is predicted to be bent (C2v configuration). The known lanthanide dichlorides SmCb, EuCl2 and YbCl2 are bent (C2v) and the Cl-R-Cl angles have been determined as 130 , 135 and 140 , respectively. Table 7 lists the vibrational frequencies of the dichlorides of Sm, Eu and Yb assigned on the basis of bent C2v geometry. 

The non-transferability of actual subsystems is manifested on all levels, even on the level of atomic nuclei. Although chemists often regard two nuclei of the same isotope as interchangeable, even such nuclei of identical lists of nucleons are not fully transferable, as evidenced, for example, by NMR spectroscopy. Chemical shifts of nuclei of identical lists of nucleons are different, precisely as a consequence of the nuclei being slightly different, caused by their different interactions with their different surroundings. Consequently, even nuclei are not rigorously transferable. 

Purification of industrial grade Cr to produce reagent-grade Cr compounds could involve processes in which 1) Cr isotope fractionation occurs and 2) fractionated Cr is lost so that the final product is shifted in 5 Cr from the initial Cr. Such an effect is suggested by the slightly positive 5 Cr values of the two reagent-grade Cr compounds listed in Table 7. However, the differences are very small. 

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