G--C quartet--a DNA-inspired Janus-GC heterocycle: synthesis, structural analysis, and self-organization.

In this communication we disclose the synthesis and characterization of a DNA-inspired self-complementary heterocycle that contains AAD-DAA H-bond acceptor/donor patterns. Whereas in the past such AAD-DAA self-complementarity has given rise to trimeric and hexameric rosettes, we now demonstrate that the same H-bonding scheme, when properly arrayed, can be used to program a tetrameric rosette, which unlike a G-quartet requires no metal binding or peripheral components for preorganization. Of note, we exploit both 2D-NOESY and DOSY 1H NMR to substantiate the tetrameric stoichiometry in this noncovalent rosette comprising 12 H-bonds.