Aggregation studies of benzoporphyrin derivative

Autor: David Dolphin, Noboru Hioka, Ethan Sternberg, David Delmarre, Ron Boch
Rok vydání: 2001
Předmět:
Zdroj: Canadian Journal of Chemistry. 79:1068-1074
ISSN: 1480-3291
0008-4042
DOI: 10.1139/v01-043
Popis: The photophysical properties of a ring B benzoporphyrin derivative 1,3-diene dimethylester were investigated in solution (water–DMSO mixtures). At low proportions of water in DMSO, the diester obeys Beer's law at all pH values and ionic strengths investigated. For solvent systems containing more than 30% water, the extent of deviation from Beer's law as a function of porphyrin concentration is attributed to formation of porphyrin dimers. Dimerization equilibrium constants (Kd) have been determined in different percentage of solvent mixtures, using absorption and fluorescence spectroscopies, and were found to exhibit a linear correlation between log (Kd) and the inverse of the dielectric constant (log (Kd) = 24.6 – 1060.4 × 1/εmix). This equation permits the calculation of Kd in mixtures of water–DMSO.Key words: porphyrins, dimerization, aggregation, fluorescence, benzoporphyrin derivative, photodynamic therapy, photosensitizers.
Databáze: OpenAIRE