SELF-ORGANIZATION IN STABLE AND METASTABLE LANGMUIR-BLODGETT-FILMS OFLIQUID-CRYSTALLINE PORPHYRINS

We report an AFM imaging study of molecular self-aggregation and organ ization in LB layers of mesogenic porphyrin derivatives. The images we re taken from molecular resolution to the mesoscopic range, as a funct ion of deposition pressure and of elapsed time after deposition. At th e molecular level, from the images we were able to determine molecular dimensions and pseudomeso-morphic structure, which was columnar. As a function of elapsed time. such images remained stable if the depositi on was performed at the pseudo-solid part of the isotherm. For deposit ion in the coexistence, condensed liquid stage, as a function of time the images showed remarkable molecular self-organization processes, oc curring over several length scales.