Abstract

FORGAN, Ross S. et al. Towards the Stepwise Assembly of Molecular Borromean Rings: A Donor-Acceptor Ring-in-Ring Complex. J. Mex. Chem. Soc [online]. 2009, vol.53, n.3, pp.134-138. ISSN 1870-249X.

The assembly of molecular Borromean Rings from constitutionally independent rings in a stepwise manner depends on the preparation of robust "ring-in-ring" complexes. The π-electron rich macrocycle bis-1,5-dinaphtho[50]crown-14 (1) is shown to form a donor-acceptor ring-in-ring complex with the π-electron poor cyclophane cyclobis(paraquat-4,4'-biphenylene) (2^{4 +} ) in solution. In the crystal superstructure of [12]·4PF₆, CH···O interactions between the polyether loops of 1 and the bipyridinium units of 2^{4 +} could disfavor the threading of dialkylammonium components of a third ring.

Keywords : Borromean Rings; Ring-in-Ring Complex; Donor-Acceptor; Supramolecular Chemistry; Crystal Structure.