Pseudorotaxanes formed between secondary dialkylammonium salts and crown ethers

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 (PhCH(2))(2)- NH2+PF6- and (nBu)(2)NH2+PF6- -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.