m‑Phenylene-Linked Dipyrrins and Their Boron–Difluoride Complexes as Variously Shaped Macrocyclic Oligomers

The effectiveness of a m-phenylene linker, which has rigidity as well as rotational flexibility, is presented to produce a series of variously shaped macrocyclic oligomers of dipyrrins and BODIPYs, whose structures were revealed by X-ray crystallography and 1H NMR analysis. Although the chemical structures of the repeating units are the same for dipyrrin/BODIPY oligomers, their absorbance and emission properties changed significantly depending on the size and shape of the macrocycles.