Frequency table

Socrates G 1994 Infrared Characteristic Group Frequencies Tables and Charts 2nd edn (Chichester Wiley)... 

The skeleton vibrations. C3NSX, CjNSXj. C NSXY, or C NSXj (where X or Y is the monoatomic substituent or the atom of the substituent which is bonded to the ring for polyatomic substituents), have been classified into suites, numbered I to X. A suite is a set of absorption bands or diffusion lines assigned, to a first approximation, to a same mode of vibration for the different molecules. Suites I to VIII concern bands assigned to A symmetry vibrations, while suites IX and X describe bands assigned to A" symmetry vibrations. For each of these suites, the analysis of the various published works gives the limits of the observed frequencies (Table 1-29). 

The data in Table 4.12 are best displayed as a histogram, in which the frequency of occurrence for equal intervals of data is plotted versus the midpoint of each interval. Table 4.13 and figure 4.8 show a frequency table and histogram for the data in Table 4.12. Note that the histogram was constructed such that the mean value for the data set is centered within its interval. In addition, a normal distribution curve using X and to estimate p, and is superimposed on the histogram. 

Adduct formation by IrCl(CO)(PPh3)2 and similar compounds results in a shift in the IR carbonyl stretching frequency (Table 2.8). 

Since one is only rarely interested in the density at a precise point on the z-axis, the cumulative probability (cumulative frequency) tables are more important in effect, the integral from -oo to +z over the probability density function for various z > 0 is tabulated again a few entries are given in Fig. 1.13. 

G. Socrates, Infrared and Raman Characteristic Group Frequencies Tables and Charts, 3rd ed., Wiley, Chichester, 2001, p. 142. 

The calculated C14—C13 DQ correlation frequency (Table 1) is 268.0 ppm correlations were expected to be observed at +93 ppm... 

Finally, the calculated C14-C15 DQ correlation frequency (Table 1) is — 291.6 ppm, with correlations expected at +58.4 ppm after folding in A single correlation is observed from the H20b proton at a DQ frequency of + 58 ppm the correlation pathway is shown by 41. 

The IR and XH-NMR spectral data for the various titanocene mono-carbonyl-phosphine complexes are compiled in Table III. Examination of the carbonyl stretching frequencies (Table III) nicely demonstrates the enhanced 7r-backbonding of the titanium center to CO as the -accepting ability of the phosphine ligand decreases. 

Further evidence for covalency effects comes from a comparison of interatomic distances and Y—0 symmetric stretching frequencies (Table 6) in the MYO4 scheelite compounds where Y =Mo or W. As the covalent character of the M—0 bond increases (as measured by xm in Table 6) and thus that of the Y—0 bond decreases, the mean Y—0 distance increases. This increase in Y—0 distance is accompanied by a decrease in the symmetric stretching frequency of the YO4 group. A similar relationship between M—0 covalency and IO4 stretching frequencies exists for the MIO4 scheelite compounds (Tarte, 1973). 

The changes in geometry (Table 1) and vibrational frequencies (Table 2) of 1 (A = C), as well as the differences in relative energies (Table 3) of isomers 2 and 3 with an increase in the quality of the theoretical method, emphasize the importance of electron correlation and basis set. Although the geometry of the CHj fragment does... 

Alexander and Gray 70) and Caulton 71) have studied the electronic spectrum of the species [Co(CN)5] . Although direct proof is lacking, it has been affirmed that the optical and E. P. R. spectra are consistent with an essentially square p5u-amidal stereochemistry and are inconsistent with a trigonal bipyramidal structure (70). It has been claimed, however, that this species may be actually six-coordinate in water, i. e. [Co(CN)5(H20)]3- (72). The spectrum of [Co(CN)5]3. has four bands of low intensity between 10 and 32 kK, as well as two high intensity bands at higher frequence (Table 7). 

Based on this principle, multi-nuclei instruments were initially built. They kept the frequency fixed while scanning the magnetic field over a wide range. This allowed the qualitative and global detection of elements by their characteristic resonance frequency (Table 9.2 and Fig. 9.5). 

These equations, which can be solved by iterative processes.4 lead to accurate estimates of transition frequencies (Table 11.19) and quite satisfactory fitting of spectra. Parallel equations for octahedral d6 complexes are ... 

In conclusion of this section we present a table of barrier heights and tunneling frequencies (Table 7.2). This table is based on the data collected by Clough et al. (1981a) and, in addition, includes the results from the later papers discussed above as well as the values of V3 for some isolated molecules. 

If the alkyl groups in any R SnX4 series are replaced by phenyl, the U9Sn signal moves to lower frequencies (Table XI), which is inconsistent with the greater electron withdrawing capability of a phenyl substituent on tin. Similar effects are found with benzyl, vinyl, and allyl groups (Tables XXX and XXXI) and may be due to the increased polarizability of these unsaturated substituents. (23) This topic is discussed further in Section III.B.3. 

The IR spectrum of camphor as KBr disc and Nujol mull were recorded on.a Perkin Elmber 58O B Infrared spectrophotometer to which Infrared data station is attached (Fig. 3). The structural assignments have been correlated with the following frequencies (Table 3). 

The structural assignments have been correlated with the following frequencies (Table l). 

P=0 Thomas and Chittenden (5,38 441 have carried out a thorough series of studies on the identification of organophosphorus compounds. The group frequency tables in these studies enable interpretation of many of the characteristic features in the spectra of nerve agents and related chemicals. Several structure-spectrum relationships give specific information on the molecule. One very valuable relation discovered by Thomas is the dependence of the position of the P=0 bond stretching vibration, vp=0, on the substituents on the phosphorus, represented by n constants ... 

The other lines in Fig. 11 are vibrational satellites. Their intensities depend on the Boltzmann factor and therefore on the frequencies of the vibrations that are involved. Knowing the temperature these frequencies can be computed from the observed intensities. The vibrations which stand a good chance of causing satellites are, of course, the ones of low frequency. Table 9 is a part of Legon, Millen and... 

The most extensive and informative data available for transition metal complexes, and indeed for transition metal compounds as a whole, come from the studies of complexes of the type A2MX6 (where A is a monovalent cation and X is chlorine, bromine or iodine). In those cases where a variety of cations in conjunction with the same complex ion have been studied it has been found that the nature of the cation has almost negligible effect on the observed resonance frequencies (Table 2), the resonances moving to slightly higher frequencies with increases in the size of the cation. 

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