Photoredox Reactions of Lead(IV) and -(II) Hydroxo Complexes

Abstract

Ligand-to-metal charge-transfer excitation of Pb(OH)62- in 0.1 M NaOH leads to the formation of Pb(0H)3- with
φ = 0.07 at λirr = 254 nm. Hydrogen peroxide was detected as an oxidation product. Upon sp excitation, Pb(OH)3-
in 0.1 M NaOH shows a yellow emission at λmax = 570 nm with φ = 1.5 X 10-3 at λirr = 254 nm. In the presence
of oxygen, this emission is partially quenched (φ = 1.2 X 10-3) and Pb(OH)3- is photooxidized to Pb(OH)62- with
φ = 0.02. A pseudo-photostationary state with 80% Pb(OH)62- is established. In the absence of oxygen, Pb(OH)3-
undergoes a photoreduction with the deposition of elemental lead.