We report the synthesis and characterization of eight C-shaped methylene-bridged glycoluril dimers (1-8) bearing hydrogen-bonding amide groups on their aromatic rings. Compounds 1-6 undergo tight dimerization in CDCl 3 solution (Ks >9 ×105 M -1);binary mixtures of 1-7 form mixtures of homodimers and heterodimers in moderately selective dimerization processes (0.23 &le K eq &le 768;0.253 &le χAB <0.933). The high affinity formation of 1·1-6·6 is due to the commensurate nature of the geometrical constraints imposed by the π-πinteractions and only two hydrogen bo...
