Influence of Acid Catalyst on the Synthesis of trans‐Porphyrins and Crystal Structure of a 5‐(Pyren‐1‐yl)dipyrromethane

Abstract A family of trans‐ porphyrins (A 2 B 2 , A 2 BC and A 2 C 2 ), including fewer fused cyclic aromatics, was synthesized using 5‐mesityldipyrromethane under negligible scrambling reaction conditions in high yields (15–48 %) with BF 3 (OEt 2 )/EtOH relative to that in trifluoroacetic acid (12–22 %) in CHCl 3 . The push‐pull trans ‐A 2 BC, Zn(II)‐carboxy porphyrins were prepared from their ester porphyrins and examined their fluorescence and electrochemical redox properties. In addition, the synthesis and single‐crystal X‐ray structure of a 5‐(pyren‐1‐yl)dipyrromethane are also reported.