J-aggregation of a water-soluble tetracationic porphyrin in mixed LB films with a calix[8]arene carboxylic acid derivative.
The molecular organization of a mixed film, containing a water-soluble tetracationic porphyrin (TMPyP) and a p-tert-butyl calix[8]arene octacarboxylic acid derivative (C8A), at the air-water interface and on a solid support (LB film), has been investigated. Although the TMPyP aggregation was not detected at the air-water interface, TMPyP J-aggregates have been found in the LB films (Y-type). Unlike tetraanionic porphyrins, for example TSPP, the TMPyP J-aggregates are not induced by a zwitterion formation. The TMPyP J-aggregation is a result of a "double comb" configuration, where porphyrins from opposite layers are interwoven in a linear infinite J-aggregate. Our results confirm that TMPyP molecules tend to self-aggregate strongly, provided the electrostatic repulsions of their peripheral groups are cancelled by the anionic groups of the C8A matrix.
Miguel
Gustavo de
Gd
Departamento de Química Física y TermodinAmica Aplicada, Universidad de Córdoba, Campus Universitario de Rabanales, Ed. Marie Curie, E-14071 Córdoba, Spain.
Pérez-Morales
Marta
M
Martín-Romero
María T
MT
Muñoz
Eulogia
E
Richardson
Tim H
TH
Camacho
Luis
L