Solution conformations of novel redox-active cyclophane based on biindolizinequinoxaline

A complete study of the conformational behavior of cyclopentadecaphane by DNMR and theoretical methods demonstrates that: (a) the macrocycle adopts syn-orientation of indolizine fragments; (b) internal rotation around the bonds between indolizine and quinoxaline moieties produces two strictly different structures in solution: in dominant non-symmetrical form (ca. 67%) the halves of the macrocycle are not equivalent while in the minor symmetrical form (ca. 33%) they can be superimposed by rotation.