title: Study on aggregation of palladium-porphyrins using room temperature phosphorescence.
abstract: This paper reported room temperature phosphorescence (RTP) behaviors of meso-tetra-(4-sulfonatophenyl) porphyrin palladium (Pd-TSPP) and meso-tetra-(4-trimethylaminophenyl) porphyrin palladium (Pd-TAPP) in bovine serum albumin (BSA) medium. It was found that Pd-TSPP self-aggregated with its increasing concentration and hetero-aggregated with Pd-TAPP when they were mixed together. The self-aggregation of Pd-TSPP resulted in the remarkably splitting of excitation spectra because of the strongly excitonic coupling and phosphorescence quenching excited by Soret band, while Q band always kept the increase in intensity. The hetero-aggregation was out of the ground-state interaction stronger than the former one owing to its electrostatic-interaction nature. It was also indicated that inorganic salts like KCl would be an aid to hetero-aggregation. The equilibrium constants of both kinds of aggregation were estimated, namely, K(hom)=1.9 x 10(5) l/mol (homo-aggregation), and K(het)=1.06 x 10(7) l/mol (hetero-aggregation).
authors.affiliation: Department of Chemistry, Shanxi University, Taiyuan 030006, China.
authors.forename: Gai-Ru
authors.initials: GR
authors.lastname: Li
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Wu
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Jin
mesh_terms: D000818:Animals; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008956:Models, Chemical; D010165:Palladium / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D011189:Potassium Chloride / Q000737:chemistry; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry*; D013053:Spectrophotometry; D013696:Temperature
chemical_list: D011166:Porphyrins; D012709:Serum Albumin; D010165:Palladium; D011189:Potassium Chloride