The photolysis of octachlorodirhenate(III) in chloroform

Under 254 nm irradiation in chloroform, [Re2Cl8]2− is converted cleanly to [Re2Cl9]−. The reaction is initiated primarily through light absorbed by the chloroform. The experimental rate expression is a ( I 0 f S [ Re 2 Cl 8 2 - ] ) 1 / 2 , where I0 is the incident light intensity and fS is the fraction of light absorbed by the solvent. The rate law is consistent with mechanisms involving either [Re2Cl8]− or [Re2Cl9]2− as an intermediate.