Design and synthesis of self-included pillar[5]arene-based bis-[1]rotaxanes

Two strategies for the design of new pillar[5]arene-based mechanically self-interlocked molecules （MSMs） are reported here. The first strategy is based on the construction of an intermediate pseudo[1]rotaxane followed by the desired bis-[l]rotaxane. The other one is based on the construction of the desired bis-[1]rotaxane directly via a condensation reaction through host-guest interactions between a mono-functionalized pillar[5]arene and the axle. The newly synthesized bis-[1]rotaxane BR was characterized by;H NMR,;C NMR, 2D NMRs (;H-;C HSQC,;H-;H COSY and NOESY) and LC-ESI-MS,which indicated compound BR displayed an self-interlocked structure in CDCl;. Surprisingly, the results of SEM, TEM and DLS showed that the compound BR could assemble into spherical nanoparticles in MeOH.