Synthesis of multi-porphyrin arrays and study of their self-assembly behaviour at the air-water interface

A series of multi-porphyrin arrays were synthesized and the self-assembly behaviour of these compounds at the air-water interface was investigated by the Langmuir-Blodgett technique. It was found that as the overall area of the porphyrin molecules was increased, upon going from a mono- to bis- to a tetra- and then to hexaporphyrin species, the intermolecular stacking between the molecules also increases, resulting in more stable monolayers. In the case of the hexaporphyrin species the intermolecular interactions are so strong that monolayer formation is irreversible. All porphyrin monolayers can be transferred to a glass surface with good transfer ratios, leading to highly ordered porphyrin films in which the chromophores are arranged orthogonal to the glass surface.