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For the first three ionized states of ozone the ordering of 2A1, 2B2 and 2A2 states has so far been controversial both experimentally and theoretically. The present work establishes assignment of the 2A2 state by using the characteristic of electron energy dependence of an asymmetry parameter (β) of photoelectron angular distribution measured with NeI, HeI, and NeII resonance radiation. From measurements of photoelectron spectra of ozone with NeI, HeI, and HeII radiation, we newly find that two bands centered at 16.50 and 17.6 eV exhibit vibrational structures with the spacings of about 850 and about 1000 cm−1, respectively. Furthermore abnormally weak bands are also confirmed at 22.7, 24.1, and 26.8 eV in the Hell spectrum.

1 and 3 become less important relative t o reaction 2 due to their higher activation energies. Thus, in our samples (large [ClF]/ [Clt]), the CIF still disappears (via reaction 2) but now the [Clz] remains constant or even increases slightly depending on the actual temperature. ConclusionsThe thermal decomposition of C1F is complex in the temperature range 2000-2950°K, and a mechanism which adequately explains the experimental results is suggested. It is reemphasizedz6 that caution is in order when inferring mechanisms from semilog kinetic plots.The results reported here also indicate that k, and k3 are similar in magnitude although a more detailed study would be required t o evaluate IC1 explicitly.Acknowledgment. The authors wish to thank R. W. Anderson and H. R. Frick for the synthesis of ClF, and W. E. Eichorn for his help in obtaining some of the experimental data. (26) A different way in which aroblems can arise has been demonstrated recently: M. W. Slack and E. s. Fishburne, J . Chem. P h i s . , 52, 5830 (1970). Publication costs assisted by the Institute of Applied Electricity, Hokkaido UniversityThe reversible dimerizations of the perylene and tetracene radical cations in concentrated sulfuric acid have been studied spectroscopically. Equilibrium constants of the monomer-dimer equilibrium at various temperatures were determined by analyzing electronic absorption spectra. From the temperature dependences of the equilibrium constants, heats of dimerization were evaluated to be 8.8 and 5.6 kcal/mol of dimer for the perylene and tetracene cations, respectively. From the present study it has also been found that when the cation dimers are formed new absorption bands appear in the near-infrared region, and the ultraviolet and visible absorption bands shift toward shorter wavelength. The appearance of the near-infrared bands in the dimer spectra are discussed in terms of both a radical-radical charge resonance and an electronic transition between the bonding and antibonding MO's constructed for the dimer, on the basis of a symmetrical sandwich dimer structure. Interactions between the two cation radicals forming the dimer in solution are discussed.

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