关键词: Langmuir-Blodgett膜, 聚集体, meso-四-(4-N)-吡啶基卟啉, 分子间相互作用, Soret带

Abstract: Pure Lanpmuir-Blodgett film of non-alkyl-substituted porphyrins-such as meso-tetra-(4-N)-pyridyl-porphyrin (H₂TPyP) and its Zn²⁺, Cu²⁺ complexes (ZnTPyP), (CuTPyP) are described. The porphyrin intermolecular interactions in chloroform solution, in L-B film and in the solid state were investigated by means of near UV absorption spectroscopy and fluorescence spectroscopy. The molecular aggregate effect on the spectra was discussed.We first analyzed near-UV absorption and fluorescence spectra of porphytins in chloroform solution and in the solid state and compared them with that in L-B film so as to study the porphyrin intermolecular interactions and their effects on the spectra. It was shown that the Soret band of porphyrins has different half band width and peak wavelength in the three cases. The case in the L-B film is just situated between the other two. It may be considered that there is some form of porphyrin molecular aggregate in the L-B film, and the intermolecular interactions within the aggregate are weaker than that in the solid state. Therefore, it could be concluded that the porphyrin molecules exist in a state of quasi-crystal in the L-B film.

Key words: Langmuir-Blodgett film, aggregate, meso-tetra-(4-N)-pyridyl-porphyrin, Intermolecular interaction, Soret Band