Self-Aggregates of Cationic meso-Tetratolylporphyrins in Aqueous Solutions

0181586 - UFCH-W 20030010 RIV US eng J - Journal Article
Kubát, Pavel - Lang, Kamil - Procházková, Kristýna - Anzenbacher Jr., P.
Self-Aggregates of Cationic meso-Tetratolylporphyrins in Aqueous Solutions.
Langmuir. Roč. 19, č. 2 (2003), s. 422-428. ISSN 0743-7463
R&D Projects: GA ČR GA203/01/0634; GA ČR GA203/02/0420
Institutional research plan: CEZ:AV0Z4032918; CEZ:AV0Z4040901
Keywords : porphyrins * DNA * point-dipole
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.098, year: 2003

Aggregation properties of meso-tetratolylporphyrins bearing cationic substituents of a lipophilic nature such as ammonium, pyridinium, phosphonium, sulfonium, and isothiouronium were studied by UV/vis and resonance light scattering spectroscopy. The exciton point-dipole approximation was used to predict the structural alignment of the porphyrin units within the aggregate. The contribution of various types of aggregates depends on the porphyrin substitution, ionic strength, and temperature of aqueous solution of the porphyrin. In general, the preferred structure of an aggregate formed by temperature-induced aggregation is the J-aggregate exhibiting the characteristically narrow, red-shifted Soret band indicating a parallel "side-by-side" arrangement of the porphyrin units. The formation of aggregates of cationic tetratolylporphyrins is controlled by both electrostatic and hydrophobic interactions, Observed aggregation properties of porphyrin derivatives bearing trimethylammonium.
Permanent Link: http://hdl.handle.net/11104/0001913