Hydrogen-Bonded Aryl Amide Macrocycles: Synthesis, Single-Crystal Structures, and Stacking Interactions with Fullerenes and Coronene
journal contributionposted on 07.03.2008, 00:00 by Yuan-Yuan Zhu, Chuang Li, Guang-Yu Li, Xi-Kui Jiang, Zhan-Ting Li
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.