Porphyrin–Ryleneimide Hybrids: Tuning of Visible and Near-Infrared Absorption by Chromophore Desymmetrization

Unsymmetrically fused
porphyrins containing one or two naphthalimide
subunits were prepared in modular syntheses relying on electron-rich
and electron-poor pyrrole building blocks. These new chromophores
show progressive changes in their electron-deficient character, while
retaining comparably small optical and electrochemical band gaps.
The intrinsic curvature and extended optical absorption of these systems
make them of interest as mono- and difunctional components of multichromophoric
assemblies.