Photochemical reduction of uranyl ion with triaryl phosphites in an anhydrous medium

Uranyl ion is photochemically reduced to uranium(V) with triphenyl phosphite, tri-o-tolyl phosphite and tri-m-tolyl phosphite in the presence of trimethylacetic acid in dry acetone. Spectroscopic techniques have revealed the primary process involves an electron transfer mechanism followed by uranyl oxygen atom transfer to phosphorus(III). Quantum yields and Stern-Volmer quenching constant measurements exhibit competition between photochemical and photophysical annihilation of optically excited uranyl ion with triaryl phosphites in non-aqueous medium. (author) 24 refs.; 3 figs.; 1 tab