Rational Synthesis of Imidazolyl Porphyrinic Molecules for Self-assembly and Water-solubility

Abstract

The objective of this work is to develop synthetic methodology for self-assembling and water-soluble imidazole-containing porphyrinic molecules. The synthesis of the following types of compounds is described: (1) Imidazole-containing porphyrinic compounds; (2) Derivatization of the imidazolyl porphyrins to obtain water-soluble imidazolium porphyrins, and (3) Improved synthesis of tetrahydrodipyrrins - a precursor of hydroporphyrins. The self-assembly of imidazolyl metalloporphyrins was examined by UV-VIS spectroscopic analysis. Each imidazoyl metalloporphyrin was found to aggregate in non-polar solvents such as CH2Cl2. The test of water solubility was also based on absorption spectroscopy. A refined synthesis of a tetrahydrodipyrrin is described for medium-scale synthesis (>10 g of the product), which facilitates access to diverse hydroporphyrins. Water-soluble porphyrinic molecules are useful for life sciences applications, and the tetrahydrodipyrrin precursors are important for the synthesis of a variety of hydroporphyrins. Taken together, this work advances the methodology for preparing a variety of synthetic porphyrins.