Synthesis and Properties of Phenanthrene-Containing Expanded Porphyrin-Based BODIPY Derivatives

Two phenanthrene-containing expanded porphyrins were synthesized by acid-catalyzed condensation and subsequently complexed with boron trifluoride etherate to afford BODIPY derivatives. Their structures and properties were investigated by spectroscopic, crystallographic, and computational methods. Changing the meso-substituent from 3,5-di-tert-butylphenyl (1) to 2,4,6-trimethylphenyl (2) significantly affects their photophysical properties. Notably, 2 exhibits large Stokes shifts (3471–3739 cm−1) and moderate fluorescence quantum yields (31–44%) in different organic solvents.