Linear and macrocyclic molecular thread, ribbon and belt assemblies of nanometric scale

Article abstract of DOI:10.1055/s-1999-3385

The hitherto longest molecular thread-belt assemblies 8, 29, 32 and 43 based on benzene-connected [3.3]metacyclophane units were prepared by means of a repetitive synthetic method. The preparation of difunctionalized [3.3]metacyclophane units (14, 22, 26) succeeded in good yields by an iteration sequence including the cyclization to the cyclophane skeleton and the derivatization of the ester groups. The covalent linkage of the [3.3]metacyclophane belt parts to the thread part leads to higher product yields compared to cyclophane belts only. The final intermolecular macrocyclizations are done by reaction of diamide, dithiol or dibromide functionalized belt fragments to obtain a minimum of single bridged benzene units in the macrocyclic thread-belt assemblies ('pseudobelts').