Journal of Physical Chemistry B, Vol.109, No.48, 22890-22898, 2005
On the quenching of MLCTRe -> bpy luminescence by Cu(II) species in Re(I) polymer micelles
Transmission electron microscopy (TEM) and dynamic light scattering (DLS) studies on acetonitrile solutions of the polymer {[(vpy)(2)-vpyRe(CO)(3)bpy]CF3SO3}(200) demonstrated that the Re(l) polymer molecules aggregate to form spherical micelles of radius R = 156 nm. Coordination of Cu(II) species to the Re (I) polymer causes a decrease in the micelle radius and a distortion from the spherical shape. Besides, the coordination of Cu(II) species to the {[(vpy)(2)-vpyRe(CO)(3)bpy] CF3SO3}(200) polymer produces the quenching of the metal to ligand charge transfer (MLCT) excited state by energy transfer processes that are more efficient than those in the quenching of the monomer pyRe(CO)(3)bpy(+) luminescence by Cu(II). Moreover, the kinetics of the quenching by Cu(II) do not follow a Stern-Volmer behavior. Conversely, the quenching of the MLCT luminescence of the Re(l) polymer by the sacrificial electron donor 2,2',2"-nitrilotriethailol, TEOA, follows a Stern-Voltner kinetics. A comparison is made between the quenching by CuX2 (X = CI or CF3SO3) and TEOA.