Photoanation of the tris(2,2'-bipyridine)ruthenium(II) cation by thiocyanate

The photochemistry of Ru(bpy)32+ in basic medium

“…The formation of MV+ on irradiation of Ru-( b~y ) ,~+ in the presence of MV2+ at high pH can be interpreted by reactions [l] to [5]: [2] * R~( b p y ) ,~+ --t Ru(bpy)," (+ hv) Reactions [2] and [3] are well known (13) and account for the quenching of the phosphorescence by MV2+. In acid solution, reaction [3] occurs so rapidly that no net reaction can be observed except for the transient absorption in flash photolysis experiments (13) due to MV+ as well as the concomitant bleaching of the absorption of Ru-( b~y ) ,~+ itself.…”

“…There are a number of reports (1-7) on the photodecomposition of solutions containing the complex ion tris(bipyridyl)ruthenium(II), Ru-( b p~) ,~+ , especially in non-aqueous solvents (2,3,6,7). It is stable to light in acetonitrile (8) and at room temperature in 0.1 M HCl (1,2).…”

“…It is stable to light in acetonitrile (8) and at room temperature in 0.1 M HCl (1,2). Decomposition yields are generally small except that, in chlorinated non-polar solvents, Gleria, Minto, Beggiato, and Bortolus (3) found a value of ca.…”

Photochemical determinants of the efficiency of photogalvanic conversion of solar energy

“…For excited triplet states of aromatic molecules and the excited states of metal complexes, rapid energy tranfer quenching by O2 (_k ^ 10 -lO 10 M _ -*-sl) (36) must be avoided. \Jhile triplet thionine appears to be insensitive to interaction wit,h solvent or other solutes in a degradative manner, although detailed studies directed toward that issue have not been conducted, *Ru(bpy)3 has been found to engage in temperature-dependent photoanation reactions, albeit with low (<10~3) quantum yields (37,38). Although the desirable redox quenching reaction can be made to overwhelm energy wasteage modes, the existence of even a very low residual quantum yield (^10""°) of these degradative reactions can render the photochemical system useless for the required operation over many million cycles.…”

Photochemical Determinants of the Efficiency of Photogalvanic Conversion of Solar Energy

“…(36) must be avoided. \Jhile triplet thionine appears to be insensitive to interaction wit,h solvent or other solutes in a degradative manner, although detailed studies directed toward that issue have not been conducted, *Ru(bpy)3 has been found to engage in temperature-dependent photoanation reactions, albeit with low (<10~3) quantum yields (37,38). Although the desirable redox quenching reaction can be made to overwhelm energy wasteage modes, the existence of even a very low residual quantum yield (^10""°) of these degradative reactions can render the photochemical system useless for the required operation over many million cycles.…”