Synthesis, Structure, and [60]Fullerene Complexation Properties of Azacalix[<i>m</i>]arene[<i>n</i>]pyridines

Abstract

Remarkably stable C60 and C70 complexes with stability constants Ks of 70 680±2060 and 136 620±3770 M−1, respectively, are formed by azacalix[4]arene[4]pyridine 1. The smaller-ring-homologue azacalix[2]arene[2]pyridine and compound 1 were readily synthesized, and they adopt a heavily twisted 1,3-alternate and a 1,2,3-partial cone conformation, respectively, in the solid state (see picture).