Spectrum of Carbon Dioxide

Fig 2 Mass spectrum of carbon dioxide. Relative peak intensities are plotted against mje. 

Fig. 27. Spectrum of carbon dioxide physically adsorbed on Cabosil.

Santrock J, Studley S A, Hayes JM (1985) Isotopic analysis based on the mass-spectrum of carbon-dioxide. Anal Chem 57 1444-1448... 

This looks far more plausible the whole enterprise of quantum chemistry, after all, is to use quantum mechanics to recover facts about chemical bonding that are well known to the chemist. If there is meshing between chemistry and quantum mechanics, do the real meshes and interfaces we saw in the last section really support strict physicalism Surely they cannot, if they are consistent with downward causation. In any case, it is not as if, in the explanation of the spectrum of carbon dioxide, there are two independent theoretical accounts that were compared and found to be consistent. Perhaps that would constitute an explanation of the less fundamental models. But neither chemistry nor the quantum mechanics of resultant Hamiltonians have the resources for independent accounts of the spectrum of carbon dioxide. Rather than an explanation of chemical structure by physical theory there was a joint venture the explanation of various facts by the use of quantum mechanics applied to a given molecular structure. There was no mesh or interface between the quantum mechanics and chemistry, at least none that required explanation. What we had was an instance of quantum chemistry, the quantum theory of atoms and molecules.14... 

It is of interest to compare the spectrum of carbon dioxide with iliai of a nonlinear Irialomic molecule such as water sulfur dioxide, or nitrogen dioxide. These molecules have (3x3)- 6 3 vibrational modes that lake the followine forms ... 

It was discovered quite early that polyatomic cations of even simple molecules formed in the mass spectrometer break into smaller positive ions and neutral fragments of various masses. For example, the mass spectrum of carbon dioxide (see Figure 1.1 and Table 1.3) exhibits ions with masses of 44, 28,12, and 16 Da. 

As an example of coupling effects, let us consider the IR spectrum of carbon dioxide. If no coupling occurred between the two C=0 bonds, an absorption band would be expected at the same w avcnumber as that for the C==0 stretching vibration in an aliphatic ketone (about 1700 cm , or 6 pm see Example 16-1). Experimentally, carbon dioxide exhibits tw o absorption maxima, one at 2350 cm (4.3 pm) and the other at 667 cm" (15 pm). 

Santrock, J., et al. "Isotopic AricJyses Based on the Mass Spectrum of Carbon Dioxide." Analytical Chemistry, 57 1985,1444 -1448. 

The UV absorption spectrum of carbon dioxide has been widely studied both experimentally [20, 22, 27, 116, 146] and theoretically [18, 21, 24,147-150] (see also Sect. 1.2.2). A huge effort has been lavished on identiiying the excited states involved in the electrrMiic transitions. To this end, electron impact spectroscopy has proved to be an additional useful diagnostic tool [151-153]. 

Hartman KO, Hisatsune IC (1966) Infrared spectrum of carbon dioxide anion radical. J Chem Phys 44 1913-1918... 

Falk M, Miller AG (1992) Infrared spectrum of carbon dioxide in aqueous solution. Vibr Spectrosc 4 105-108... 

Fig. A.IO Gas phase photo elearon spectrum of carbon dioxide adapted from [23]...

The band contours observed for parallel bands of linear molecules are similar to those found for diatomic molecules that is, only P- and R-branches are observed. For perpendicular bands, however, the Q-branch is also present and may be quite intense. These aspects are illustrated by the observed spectrum of carbon dioxide shown in Figure 4-33 (located in pocket on inside back cover). 

Figure 23.19 shows the rotational Raman spectrum of carbon dioxide. From the splitting between the lines, 3.09 cm , calculate the equilibrium bond lengths. 

Figure 23.19 Rotational Raman Spectrum of Carbon Dioxide. The axis is the difference between the reciprocai waveiength of the incident and that of the scattered radiation. The peak at zero Raman shift is the scattered radiation with no change in energy of the moiecuies. From L. Ciaron Hoskins, J. Chem. Educ., 54, 642 (1977).

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