Hydrogen-Bonded Aryl Amide Macrocycles: Synthesis, Single-Crystal Structures, and Stacking Interactions with Fullerenes and Coronene

Six hydrogen-bonded shape-persistent aryl amide macrocycles have been prepared by using one-step
and (for some) step-by-step approaches. From the one-step reactions, 3 + 3, 2 + 2, or even 1 + 1
macrocycles were obtained in modest to good yields. The reaction selectivity was highly dependent on
the structures of the precursors. The X-ray structural analysis of two methoxyl-bearing macrocycles revealed
intramolecular hydrogen bonding and weak intermolecular stacking interaction; no column-styled stacking
structures were observed. The 1H (DOSY) NMR, UV−vis, and fluorescent experiments indicated that
the new rigidified macrocycles complex fullerenes or coronene in chloroform through intermolecular
π-stacking interaction. The association constants of the corresponding 1:1 complexes have been determined
if the stacking was able to cause important fluorescent quenching of the macrocycles or coronene.