Pseudorotaxanes formed between secondary dialkylammonium salts and crown ethers

Abstract

A very simple self-assembling system, which produces inclusion complexes with pseudorotaxane geometries, is described. The self-assembly of eight pseudorotaxanes with a range of stoichiometries - 1:1, 1:2, 2:1, and 2:2 (host: guest) - has been achieved. These pseudorotaxanes self-assemble from readily available components - well-known crown ethers, such as dibenzo[24]crown-8 and bis-p-phenylene[34]crown-10, and secondary dialkylammonium hexafluorophosphate salts, such as (PhCH2)2-NH2+ PF 6- and (MBu)2NH2+PF 6- - and have been characterized not only in the solid state, but also in solution and in the "gas phase". The pseudorotaxanes are stabilized largely by hydrogen-bonding interactions and, in some instances, by aryl-aryl interactions. © VCH Verlagsgesellschaft mbH, 1996.