Fig. 2.

Single crystal structural analysis of the Fmoc-G-PNA tetramer. a The asymmetric unit. b Supramolecular parallel array of the asymmetric unit, obtained through intermolecular H-bonds and aromatic-aromatic interactions. c Truncated view of a ribbon-like structure formed in the crystallographic $\overrightarrow{c}$-direction. The Fmoc group and aliphatic chains are represented by gray and orange spheres, respectively. d Non planar cyclic tetrameric structure. e Quadruplex inspired superstructure view down crystallographic $\overrightarrow{a}$-direction. f Herringbone-like arrangement of the G-wire in a higher-order structure produced by lateral orientation. The H-bonds are shown in light blue dashed lines and the Fmoc rings are represented by a gray sphere