Ion photochemistry

In addition to the photochemistry of DNA, photoreactions of various cell components, such as membrane proteins, enzymes and other biomolecules may also be relevant to photo-induced cell killing in some cases (Kalisvaart, 2001). In drinking water UV treatment, usually only the photochemical reactions that are induced by direct irradiation are observed. However, if nitrate ion photochemistry (producing OH radicals) is involved, the complex radical chemistry of DNA/RNA and of their fragments may prevail (Pogozelski and Tullius, 1998). 

In the context of this work we found it interesting to make the transition from ion spectroscopy in the gas phase to ion photochemistry in liquid solution. While the basic processes are still the same the different environment drastically modifies the results known from gas phase studies. The mobility of ions and electrons in solution is greatly different, the energy of the spectroscopie states is changed, and reactive interaction with the solvent or other added species becomes possible. A very first step in this direction of preparative ionic photochemistry was reported before from our laboratory treating the benzene molecule as an example. More results have now been obtained relating to the mechanism of ion fonnation and its yield, the nature of the intermediates, and the conditions favouring product yield. As a first case the conversion of benzene to phenol and biphenyl in aqueous solution was studied followed by the study of reactions of benzene derivatives in water and other solvents /3/. 

Exclted states, primary processes Lanthanides, electronic structure Lanthanides, excited states Lanthanides, photochemistry Actinides, electronic structure ActlnldCs, excited states Uranyl ion, photochemistry Uranyl complexes, photochemistry Uranyl Ion, luminescence quenching Photochemistry, actinide alkyls... 

Four further papers from the same laboratory illustrate the potential of metal-ion photochemistry in micelles. The annelide (18) (see ref. 67, p. 189) forms a stable silver ion adduct (123) which reacts by electron-transfer from (124) on photochemical excitation.The resulting Ag(0) complex is stable to... 

Carbonium ions, gaseous, from the decay of tritiated molecules, 8, 79 Carbonium ions, photochemistry of,... 

---