Decay of an Ir(II) complex in aqueous solutions studied by pulse radiolysis. Effect of poly(styrenesulfonate) on the mechanism

Pulse radiolysis of aqueous solutions containing [Ir(bpy)2(C3,H(bpy)]/sup 3+ 1,2/ or its basic form (Ir(III)3+ and Ir(III)2+, respectively) in the presence of 2-propanol produces the reduced Ir(II)2+ species (the reduction is at the bpy site). The decay of Ir(II)2+ is strongly enhanced by the presence of small concentrations of poly(styrenesulfonate)(PSS). Both intrapolymer and interpolymer bimolecular reactions of Ir(II)2+ are observed, followed by the formation of a hydride. Exchange of Ir(II)2+ between different polymer molecules is enhanced by ir(II)2+ in the bulk. The effects of [PSS], pulse intensity, and [Ir(III)2+] on the decay kinetics are reported and discussed. The overall effect of PSS on Ir(II)2+ is the catalyzed formation of hydrogen