Singlet molecular oxygen from superoxide anion and sensitized fluorescence of organic molecules.

The superoxide anion, O(2)-, evolves singlet molecular oxygen in dimethylsulfoxide solution. Pronounced water quenching of superoxide-sensitized luminescence is indicative of the preferential generation of the (1)sigma(g)+ state. Recent identification of O(2)- in the xanthine oxidase system suggests that the generation of singlet oxygen may also occur in enzymatic systems.