Toward interlocked molecules beyond catenanes and rotaxanes

[GRAPHICS] A linear bis secondary dialkylammonium ion containing scaffold-based upon an anthracenyl core-has been synthesized. It has been demonstrated that it is possible to dock either one or two dibenzo[24]crown-8 (DB24C8) macrocycles onto this scaffold to afford either a [2]- or [3]pseudorotaxane, respectively, In solution, the association constants for the formation of each of these species has been quantified by employing H-1 NMR spectroscopy, and both species survive in the gas phase as evidenced by FAB mass spectrometry. Additionally, the X ray crystal superstructure of the [3]pseudorotaxane has been determined.