Intermolecular complexes between sulé de radical cations from ¯-hydroxy sulé des and phosphate

Triplet-sensitized oxidation of 2-(methylthio)ethanol (2-MTE) and photosensitized formaldehyde formation from 2-MTE were measured in aqueous solutions. The formaldehyde quantum yields were measured in steady-state experiments; whereas the time-resolved detection of dimeric sulfur radical cations (S ( S) C was followed in nanosecond laser e ash photolysis. 4-Carboxy- benzophenone was the triplet sensitizer in both types of experiments. It was found that the lifetimes of the (S( S) C radicals increased in the presence of phosphate buffer, sodium perchlorate, or D 2O. There were corresponding decreases in the formaldehyde yields for these same experimental factors. The phosphate case was discussed in some detail in terms of a new intermolecular complex between the sule de radical cations and the oxyanions.