Glycoluril-based host molecules

Fig. I (a) Glycoluril-based host molecules, (b) Dimeric arrangement of molecules in the crystal structure of 3b. (c) Computer-modeled representation of the binding of resorcinol in Host 3b. (d) The three conformations of Host 6 (from left to right) anti-anti, anti-syn, and syn-syn. View this art in color at www.dekker.com.)...

Glycoluril-based host molecules were used as components of substrate-selective catalysts. Using nature as a guide, catalytically active metal centers were linked to the receptor cavities. These supramolecular systems were synthesized to mimic well-known processes in natural... 

In another approach to introduce liquid crystallinity, aliphatic tails were connected to the convex side of a glycoluril-based host (23. Fig. 6a).It was reasoned that in the solid state, this host would form dimers, in a similar way as the parent compound 3b. As can be seen in Fig. 6c. such a dimer resembles the structure of a typical rod-like mesogen. Although the material formed by 23 exhibited the typical features of a liquid crystal, i.e., birefringent optical textures and a high degree of malleability, calorimetric and powder diffraction measurements showed that it was a plastic crystal composed of lamellae of dimers (Fig. 6c). Strong Ti-n interactions between the aromatic surfaces of adjacent molecules are the reason the material is not liquid crystalline. The... 

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