Integrated intensity of the infrared

If we further assume that the vibrational wavefunctions associated with normal mode i are the usual harmonic oscillator ones, and r = u + 1, then the integrated intensity of the infrared absorption band becomes... 

Crawford (Jj ) has also shown that the integrated intensities of the infrared absorption bands of isotoplcally related molecules must obey two sum-rules, one of which, the so-called F-sum rule, may be written constant. Here the... 

Very recently Boumay and Marechal (6 have studied the integrated intensities of the Infrared absorption bands of the dimers of acetic acid and acetic acid-di. For these molecules they find that the intensity of the band attributed to the OH—0 antisymmetric stretching mode is twice that of the corresponding OD—0 band, whereas the intensity ratio in the... 

Figure 7 Hydroperoxide index (HI) determined from mid-infrared spectroscopy (ratio of the integrated intensity of the 3,552 cm 1 band to the integrated intensity of the band at 2,010 cm-1) as a function of total hydroperoxide content measured by iodiometric titration.

The integrated intensity of the satellite spectrum is very close to that of the trapped electron spectrum. The former spectrum decays concomitantly with the latter either with photo-bleaching with the infrared... 

The integrated intensity of an infrared absorption band is given by... 

Infrared detection represents one of the first strategies used to monitor protein hydrogen exchange [60]. Most IR studies measure the integrated intensity of the... 

The positive inductive effect of the methyl group in polyisoprene enhances the rate of ozone addition to the double bonds from 6 10" for SKD to 4 10 M s for Carom IR 2200. The infrared spectra of ozonized, 4-tram-polyisoprene (Z-IR) show two intense bands at 1,100 and 1,725 cm, characteristic of ozonide and keto groups, respectively [19, 35], These spectra are identical with the well-known spectra of l,4-c/s -polyisoprenes (E-IR), as far as ozonide and carbonyl bands are concerned [22, 36], It was found that the integrated intensity of the peak at 1,100 cm in the E-IR and Z-IR spectra is equal for one and the same amount of reacted ozone. By analogy with the peak at 1110 cm, the integral intensity of the peak at 1,725 cm is also one and the same. The latter show that, according to the infrared spectra, the degradation efficiencies of E-IR and Z-IR with respect to the amount of consumed ozone do not practically differ. 

We consider, here, the case of infrared absorption spectroscopy. Raman intensities have been treated in a parallel way [6]. In the double harmonic approximation (where the forces and the changes in the total molecular dipole moment are linear with atomic splacements) the integrated intensity of the i-th normal mode is related to molecular properties by the relation ... 

While it is common knowledge that isotopic substitution alters the vibration frequencies of normal modes, it may be less well known that the Intensity of the corresponding infrared absorption band must be affected as well. Crawford (lj ) has shown that within the harmonic approximation the integrated intensity of an infrared absorption band, F., is given by... 

It is noAV possible to outline the cases in Avhich transitions are forbidden by the symmetry of the molecule. Consider first the integrals which determine the intensity of the infrared spectrum, namely,... 

Figure 5.25 Time dependence of the half-width and vibrational frequency of the amorphous infrared band, the integrated intensity of the regular helical bands with the different critical sequence length (m), and the intensity of the toluene band evaluated for the solvent-induced crystallization process of a glassy syndiotactic polystyrene sample. Immediately after the injection of toluene, the half-width of the amorphous band increased, indicating an enhancement of thermal motion in the amorphous chains. This results in the formation and growth of regular helical segments [116,117].

In expression (1.29) oc>k is the harmonic frequency of the vibration. Taking into account relations (1.28) and (1.29) the following expression for the integrated intensity of an infrared absoiption band is obtained... 

Among these techniques, infrared spectroscopy has been most frequently used for determining the coordination modes of NCS . The v(CN), v(CS), and 5(NCS) frequencies as well as integrated intensities of the v(CN) band have been utilized. Table IV summarizes the frequency ranges for different types of NCS coordination. 

Figure 2.51 Plots of azide surface concentration, T, against electrode potential, , for the silver electrode in 0.01 M NaN3/0.49M NaC104. The solid curve is as determined by differential-capacitance potential measurements, and the dashed curve from the integrated infrared intensities of the positive-going bands in Figure 2.50. Copyright 1986 American Chemical Society.

Above we have looked at the translational spectra of binary systems. These are obtainable experimentally at sufficiently low densities, especially when absorption of the infrared inactive gases is studied. An induced spectrum may be considered to be of a binary nature if the integrated intensity varies as density squared. In that case, the shape of the densities-normalized absorption coefficient, cc/q Q2, is invariant, regardless of the densities employed. ... 

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