Self‐Assembled Single‐ and Double‐Stack π‐Aggregates of Chlorophyll Derivatives on Highly Ordered Pyrolytic Graphite

Abstract The highly efficient, light‐harvesting antennae systems present in chlorosomes of green phototrophic bacteria, such as Chloroflexus aurantiacus , serve as a model for the design of bioinspired nanostructured materials. A semisynthetic zinc chlorin, derived from natural chlorophyll a , is used as a building block that self‐assembles into excitonically coupled chromophore stacks. Temperature‐dependent UV/Vis and circular dichroism spectroscopic measurements show the reversible formation of soluble chiral aggregates of this new zinc chlorin dye. High‐resolution scanning tunneling microscopy and atomic force microscopy studies reveal the formation of two types of well‐ordered π‐stacked aggregates on highly ordered pyrolytic graphite.