Self-Sorting Molecular Clips

We report the synthesis and characterization of 12 C-shaped methylene-bridged glycoluril dimers (1−12) bearing H-bonding groups on their aromatic rings. Compounds 1, 2, (±)-4a, (±)-5, (±)-7, and 8 form tightly associated homodimers in CDCl₃, due to the combined driving force of π−π and H-bonding interactions. Compounds 2, (±)-5, and 8, having disparate spatial distribution of their H-bonding groups, display the ability to efficiently distinguish between self and nonself even within three-component mixtures in CDCl₃. When the spatial distributions of the H-bonding groups of the molecular clips are similar (e.g., 1 and 2), a mixture of homodimers and heterodimers is formed. The effect of various structural modifications (e.g., chirality, side chain steric bulk, number and pattern of H-bonds) on the strength of self-assembly and the fidelity of self-sorting are presented. On the basis of these results we prepared self-sorting systems comprising three (e.g., 1, (±)-5, and (±)-7) and even four (2, (±)-5, 9, and 10) components. The potential of molecular clips 1−12 as robust, functionalizable, self-sorting modules to control the noncovalent interaction network in systems chemistry studies is described.