PHOTOLYSIS OF FEOH2-SOLUTION - PHOTODISSOCIATION KINETICS AND QUANTUMYIELDS( AND FECL2+ IN AQUEOUS)

Photodissociation of FeOH2+ and FeCl2+ complexes has been studied by p ulsed laser spectroscopy (lambda = 347 nm) techniques. Transient bleac hing of FeOH2+ was observed due to the dissociation FeOH+ --> Fe2+ + O H. (at lambda = 347 nm). The observed bleaching involved the photoredu ction of the species FeOH2+ to iron(II) complexes. These latter specie s showed a much lower absorption. Concomitant formation of the Cl-2(.- ) anion radical was observed due to the reactions FeCl2+ --> Fe2+ + Cl -. (at lambda = 347 nm) and C1' + Cl- - Cl-2(.-). The experimental fin dings allowed us to suggest a reaction sequence involving Cl-., Cl-2(. -), ClOH.- and OH. radicals. The quantum yields found by laser kinetic spectroscopy for FeOH2+ and FeCl2+ photodissociation were 0.21 +/- 0. 04 and 0.5 +/- 0.1, respectively.