Multiple hydrogen-bond-mediated molecular duplexes based on the self-complementary amidourea motif.

The self-complementary amidourea motif, which was stabilized by four intermolecular tricenter hydrogen bonds, was investigated in solution and in the solid state. Extensive studies on oligomer 2 indicated that the hydrogen-bonding mode could persist in longer molecular duplexes based on the amidourea motif. The dimerization constants of 2b.2b in various DMSO-d(6)/CDCl(3) mixtures were determined quantitatively by (1)H NMR dilution studies, which suggested that the homoduplex was highly stable in low polar solvents.