Design, Synthesis, and Characterization of Novel Photosensitizers for Use in Molecular Machines

Abstract

Phosphorus porphyrin-naphthyl compounds were synthesized and evaluated for future use as an electron acceptor/donor system within a photoactivated molecular shuttle. This evaluation consisted of characterizing the redox and optical properties of the systems, as well as determining the formation constant of the complex formed between the naphthyl group in each compound and a previously reported macrocycle, cyclobis(paraquat-p-phenylene) (CBPQT), with affinity towards various naphthyl derivatives. This data was holistically reviewed and used to evaluate the potential use of phosphorus porphyrin-naphthyl compounds as an electron donor/acceptor system within a molecular shuttle. Furthermore, an informed design for such a molecular shuttle was produced, and steps towards its synthesis were taken. Two other projects in which novel photosensitizers were synthesized and characterized are detailed here. The purpose of these two projects is to extensively identify their optical and redox properties such that they may be used in future systems such as molecular machines or artificial photosynthesis. The first project explores a series of phosphorus tetraphenylporphyrin derivatives in which the phenyl rings of the porphyrins have various amounts of methoxy groups adorning them. The second project explores a novel phosphorus porphyrin/aluminum porphyrin heterodimer. The goal of which is to characterize the interactions of the chromophores when no exciton coupling is observed.