Symmetry-Breaking Charge Separation in a Nanoscale Terrylenediimide Guanine-Quadruplex Assembly

• Published in: Journal of the American Chemical Society Vol. 141; no. 44; pp. 17512 - 17516
• Main Authors: Powers-Riggs, Natalia E, Zuo, Xiaobing, Young, Ryan M, Wasielewski, Michael R
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 06.11.2019; Amer Chemical Soc; American Chemical Society (ACS)
• Subjects: Absorption; Chemical structure; Chemistry; Chemistry, Multidisciplinary; G-Quadruplex; Guanine; hydrogen bonding; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; moieties; Physical Sciences; Scattering; Science & Technology; spectroscopy; wide-angle X-ray scattering; X-RAY SOLUTION; BIOLOGICAL MACROMOLECULES; DNA; SOLUTION SCATTERING; G-QUARTETS; SINGLET FISSION; CATION; PERYLENE
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.9b10108

Guanine-quadruplex (G-quadruplex) assemblies provide a useful platform for studying the spatial, structural, and photophysical effects of intermolecular interactions. Coupling a single guanine moiety to terrylenediimide (TDI)a chromophore with a large extended π-surfaceproduces a structure (GTDI) that assembles in plate-like tetramers, with the potential of undergoing tunable π-stacking. At high concentrations (3 × 10–3 M), GTDI self-assembles into a nearly monodisperse G-quadruplex structure of 16 layers, with strong π-overlap between TDI moieties, observed by small- and wide-angle X-ray scattering. Transient absorption spectroscopy reveals that excitation of TDI in the G-quadruplex results in symmetry-breaking charge separation to form ion pairs within the structure, owing to the strong π-overlap enforced by the hydrogen-bonding. These assemblies yield important insights into the interplay of noncovalent interactions in the assembly of ordered chromophoric arrays.