Double-Helix Supramolecular Nanofibers Assembled from Negatively Curved Nanographenes

Abstract

The layered structures of graphite and related nanographene molecules play key roles in their physical and electronic functions. However, the stacking modes of negatively curved nanographenes remains unclear, owing to the lack of suitable nanographene molecules. Herein we report the synthesis and one-dimensional supramolecular self-assembly of negatively curved nanographenes without any assembly-assisting substituents. This curved nanographene self-assembles in various organic solvents and acts as an efficient gelator. The formation of nanofibers was confirmed by microscopic measurements, and an unprecedented double-helix assembly by continuous π-π stacking was uncovered by three-dimensional electron crystallography. This work not only reports the discovery of an all-sp 2-carbon supramolecular π-organogelator with negative curvature, but also demonstrates the power of three-dimensional electron crystallography for the structural determination of submicrometer-sized molecular alignment. File list (4) download file view on ChemRxiv KatoWNGgel_ChemRxiv.pdf (4.62 MiB) download file view on ChemRxiv TOC_KatoWNGgel.png (833.97 KiB) download file view on ChemRxiv SI_KatoWNGgel_ChemRxiv.pdf (3.78 MiB) download file view on ChemRxiv CIF_KatoWNGgel.cif (2.36 MiB)

Hydrogen properties in an organic molecule revealed by XFEL and electron crystallography

“…An initial structure was then refined using a model with elongated riding hydrogen bond and partially charged atoms as described briefly in the main text and in detail below. Scaling between the experimental data and the model was adjusted as previously described 47 . The geometrical restraints were finally removed, while B-factors were kept restrained with commands SIMU and ISOR.…”

Diels–Alder Cycloaddition with CO, CO2, SO2, or N2 Extrusion: A Powerful Tool for Material Chemistry

“…The application possibilities listed above have been discussed in this review. Particular attention is paid to nanographenes, including functionalized and heteroatoms-doped ones, which preparation and new applications constitute a “hot topic” in science and technology [ 6 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 ]. Currently, only bottom-up methods, where nanographene is constructed from smaller entities by stepwise organic synthesis, allow the preparation of nanographenes, including functionalized and doped ones, with perfect control of shapes and sizes and, therefore, perfectly defined properties [ 2 , 5 , 6 , 11 , 12 ,…”

“…It should be added that nanographenes (graphenoids), obtained via reactions discussed in this review, can be planar or otherwise distorted, that is, non-planar, one- (1D), two- (2D), and three-dimensional (3D) [ 6 , 11 , 12 , 17 , 23 , 24 , 25 , 26 , 36 , 38 , 40 , 43 , 46 , 47 , 49 , 52 ]. Graphenoids with planar sheets of varying size, shape, and periphery have made great progress in practical applications of electronics, energy storage, catalysis, and biosensing [ 6 , 11 , 12 , 14 , 15 , 16 , 17 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 42 , 44 , 47 , 50 , 52 , 53 ]. In recent years, a growing number of graphenoid studies have focused on unusual curved and warped stru...…”

“…Graphenoids with planar sheets of varying size, shape, and periphery have made great progress in practical applications of electronics, energy storage, catalysis, and biosensing [ 6 , 11 , 12 , 14 , 15 , 16 , 17 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 42 , 44 , 47 , 50 , 52 , 53 ]. In recent years, a growing number of graphenoid studies have focused on unusual curved and warped structures such as bowls, helices, and saddles, on account of their structural variation and unique physical and chemical properties [ 6 , 11 , 12 , 14 , 15 , 16 , 17 , 20 , 22 , 23 , 24 , 25 , 26 , 27 , 32 , 33 , 35 ,…”

Five‐Fold Symmetric Pentaindolo‐ and Pentakis(benzoindolo)Corannulenes: Unique Structural Dynamics Derived from the Combination of Helical and Bowl Inversions

“…Corannlenes show characteristic conformational dynamics,w hich affect the key properties and play important roles in some of the above applications.T herefore,s tructural modifications of corannulene have also been an attractive area of research, which is getting recognized as an advantage of curved nanographenes. [6][7][8] Despite such developments,p eripherally heteroarene-fused corranulenes have been limited to aza-indenocorannulene 1 reported by Siegel and Baldridge, [8f] pyrrolefused corannulene 2 reported by Nozaki and Ito, [8d,g] and isoquinoline-fused corannulene 3 reported by Stuparu (Scheme 1). [8j] Even simple alkylamino-and arylamino-substituted corannulenes 4a-j have only recently been reported.…”