Rotaxanes Capped with Host Molecules: Supramolecular Behavior of Adamantylated Bisimidazolium Salts Containing a Biphenyl Centerpiece

• Published in: Chemistry : a European journal 2015-08, Vol.21 (33), p.11712-11718
• Main Authors: Branná, Petra, Rouchal, Michal, Prucková, Zdeňka, Dastychová, Lenka, Lenobel, René, Pospíšil, Tomáš, Maláč, Kamil, Vícha, Robert
• Format: Article
• Language: English
• Subjects: Adamantane - analogs & derivatives; Adamantane - chemistry; Aggregates; Axles; beta-Cyclodextrins - chemistry; Binding; Binding Sites; Biphenyl Compounds - chemistry; Capping; Chemistry; cucurbituril; cyclodextrins; host-guest systems; Imidazoles - chemistry; Models, Molecular; Molecular Structure; Rotaxanes; Rotaxanes - chemistry; Salts - chemistry; Slippage; supramolecular chemistry; Terminals
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201501353

Bisimidazolium salts with one central biphenyl binding site and two terminal adamantyl binding sites form water‐soluble binary or ternary aggregates with cucurbit[7]uril (CB7) and β‐cyclodextrin (β‐CD) with rotaxane and pseudorotaxane architectures. The observed arrangements result from cooperation of the supramolecular stopper binding strength and steric barriers against free slippage of the CB7 and β‐CD host molecules over the bisimidazolium guest axle. Who'd have guest: Bisimidazolium salts with one central biphenyl binding site and two terminal adamantyl binding sites are prepared and used as guest molecules for construction of self‐assembled (pseudo)rotaxanes in aqueous solution. Guests with structures that offer greater hindrance to the cucurbit[7]uril (CB7) and β‐cyclodextrin (β‐CD) host molecules' free slippage over the guest axle are able to bind a higher number of host units.