Unprecedented cucurbituril-based ternary host–guest supramolecular polymers mediated through included alkyl chains

Abstract

Novel supramolecular polymers constructed from Q[8] and 1′,1′′-(alkylene-1,4-diyl)bis(1-butyl)-4,4′-(bipyridine-1,1′-diium)bromide (alkylene = hexylene, octylene) (1, 2) have been fabricated and characterized on the basis of a series of NMR, SEM, and DLS techniques. In particular, single crystal X-ray diffraction analysis clearly reveals their ternary host–guest construction nature by mediating the Q[8] host molecule through two terminal butyl chains (that are simultaneously included inside the host cavity) of two guest molecules depending on multiple hydrogen bonding interactions between the host and guest molecules as well as between the host and host molecules with the total energy amounting to as high as 161.2 kJ mol⁻¹. This represents the first example of ternary host–guest supramolecular polymers that are mediated through alkyl chains instead of aromatic moieties included.