Multiply Stranded and Multiply Encircled Pseudorotaxanes

The self-assembly of four multicomponent rotaxane-like complexes, in which either (a) three or four dibenzo[24]crown-8 rings encircle threadlike oligoammonium cations [PhCH 2 (NH 2 + CH 2 C 6 H 4 CH 2 ) n NH 2 + CH 2 Ph] ( n = 2 or 3) to form multiply encircled pseudorotaxanes, or (b) three or four dibenzylammonium ions are threaded simultaneously through large macrocyclic polyethers, viz ., tris- p -phenylene[51]crown-15 and tetrakis- p -phenylene[68]crown-20, to give multiply stranded pseudorotaxanes, is described. These supramolecular entities are created on account of stabilizing [N + H···O] and [C H···O] hydrogen bonds, supplemented occasionally by aromatic face-to-face and edge-to-face interactions, and [C H···F] intermolecular bonds. Evidence for the existence of these diverse pseudorotaxane architectures in solution, in the solid state, and in some cases, in the “gas phase”, is provided by 1 H NMR spectroscopy, X-ray crystallography, and mass spectrometry, respectively.