Oxygen, absorption coefficients intensities

Fig. 2. Absorption spectrum of oxygen in the Schumann-Runge band system. The absorption coefficient, k, is defined by the equation I = la exp ( — kx), where h and I are the incident and transmitted light intensities and x is the layer thickness of the absorbing gas reduced to STP. This figure is taken from ref. (101) with the permission of The Journal of Chemical Physics.

The most recent measurements of the absorption coefficients of oxygen have been made by Watanabe et al. (101). For the transition 32u- -32 absorption intensities in the Schumann-Runge bands are shown in Figure 2 and in the Schumann-Runge continuum in Figure 3. 

In Fig. 14, the UV spectra of the domino oxidation products are shown. As the number of oxatetrasilacyclopentane rings increases, the lowest energy absorption maximum shifts bathochromically, and the molecular extinction coefficient becomes far larger (10 270 nm (s 3200), 11 273 nm (s 7600), 12 292 nm (s 25000), 13 297 nm (s 51900). The intense absorption of the order 104 is remarkable because these molecules contain no obvious chromo-phores which should give such intense absorption. Since the intense absorption is not observed in the ladder polysilanes, it is apparently due to the electronic effect of the oxygen atoms on the Si-Si a conjugation systems. 

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