| Abstract: | Deactivation Behaviour of Arenes and Heteroarenes. XII. Kinetics of Photodimerization of Akridizinium Salts Resulting from the photo-kinetic parameters of the deactivation of the akridizinium ion the photodimerization and -monomerization of the dimers obtained are investigated, and the rate constants of partial processes are determined. The values of the quantum yield of the dimerization (c∞) in methanol and the monomerization are 0,23 and 0,49, respectively. The presence of compounds with heavy atoms, electron donors and anions of high polarisibility results in a decrease of the quantum yields. In the case of the dimerization process this effect is more intense than in the case of monomerization. From the comparison of these results with those of fluorescence quenching it can be concluded, that non-luminescent excimers with a life-time of about 1 ns are formed intermediately. |
