The association of water soluble tetraanionic porphyrins with poly(vinylpyrrolidone) (PVP) occurs in dilute buffered aqueous solutions, as evidenced by the absorption spectral changes. Klotz plots for porphyrin-PVP association at 298 K yield association equilibrium constants of 1.1 x 10('7) M('-1) and 11.2 x 10('7) M('-1) for (')M = 40,000 and 10,000 PVP, respectively. Thermodynamic parameters for binding indicate a negative entropy, suggesting interactions other than nonspecific hydrophobic effects in the associative process. Chelation of Cu('+2) by the porphyrin is slowed dramatically in the presence of PVP. Kinetic analysis fits a mechanism in which only free porphyrin coordinates to Cu('+2) and the observed rate constant provides a measure of the porphyrin-PVP association constant. The lack of reactivity of the porphyrin bound to PVP indicates that the porphyrin microenvironment involves little contact with the bulk aqueous solution Electron transfer quenching of surfactant ruthenium complexes by methyl viologen has been demonstrated to be an inefficient process due to aggregation of the complexes in aqueous solutions. This fact is further supported by observation of a red shift in the emission maximum over a narrow complex concentration range near the cmc. The cmc values decreases as the hydrocarbon chain length of the surfactant bipyridine increases as a result of an increase in the hydrocarbon-hydrocarbon chain interaction. The replusion of the dicationic viologen quencher from the vicinity of the positively charged micelle surface results in low quantum yields for the reduction of mv('+2) to mv('+(,(.))) in presence of sacrifical electron donor. Kinetic treatment of the data showed that two independent fractions of the ruthenium existed (free and micellized) and the quenching occurs exclusively with the free fractions as evidenced from the lifetime decay quenching studies where two exponential decays are observed: fast and slow. The fast component indicates quenching of the free ruthenium fraction and the slow component is the micellized ruthenium complex which is unquenched