Chiral Carbonaceous Nanotubes Containing Twisted Carbonaceous Nanoribbons, Prepared by the Carbonization of Chiral Organic Self‐Assemblies

Abstract

Single-handed helical silica nanotubes containing chiral organic self-assemblies were prepared by using a supramolecular templating approach. After carbonization and the removal of the silica, single-handed helical carbonaceous nanotubes that contained twisted carbonaceous nanoribbons were obtained. It is believed that the nanotubes formed as a result of the adsorption of low-molecular-weight gelators. The twisted nanoribbons were formed because of the carbonization of the organic self-assemblies. The samples were characterized by using field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and circular dichroism. For the samples carbonized at 900 °C for 3.0 h, a partially graphitized structure was identified. The circular dichroism (CD) spectra indicated that the twisted nanoribbons exhibited optical activity. The CD spectrum was simulated by using time-dependent density functional theory. The results suggested that the CD signals originated from the chiral stacking of aromatic rings.

Single‐Handed Helical Carbonaceous Nanotubes: Preparation, Optical Activity, and Applications

“…[33,34] Recently, helical carbonaceous nanotubes were prepared via the carbonization of organopolymeric nanotubes, [7][8][9] organic-inorganic hybrid silica nanotubes, [21][22][23][24][25] or organic compounds within silica nanotubes. [26] The handedness of the carbonaceous nanotubes was consistent with that of their starting materials. The helical carbonaceous nanotubes exhibited optical activity, and could be used as chirality inducers and for lithium-ion storage.…”

“…[11] The cationic gelators L-4, D-4, LL-5, and DD-5 can self-assemble into twisted nanoribbons in ethanol. [25,26] …”

“…After carbonization and the removal of silica, left-and right-handed helical carbonaceous nanotubes containing twisted nanoribbons were obtained (Figure 5). [26] The formation of this hierarchical structure is illustrated schematically in Scheme 1, route C. First, helical silica nanotubes containing templates are prepared. During the drying process, the templates shrink.…”

“…[15][16][17][18][19][20][21][22][23][24][25][26][27] Chiral carbon dots, [15,16] chiral single-walled carbon nanotubes (SWNTs), [17][18][19] helical carbon nanofibers, [20] and helical carbonaceous nanotubes [7][8][9][21][22][23][24][25][26] have been successfully prepared. The optical activity of chiral carbon dots is controlled by their chiral protecting groups, and they can be used as chirality inducers and sensors.…”

Multiple‐Stimuli Responsive Luminescent Gels Based on Cholesterol Containing Benzothiadiazole Fluorophores

“…[5,6] As we know, nanotubes, which have hollow structure with less than 100 nm inner diameters, have highly potential applications in drug delivery and nanoobjects. [7] In addition, the helical nanostructures constructed from π-conjugated fluorescent LMWGs, such as twisted ribbons and fibers, are also a topic of increasing interest [8] due to their academic importance and promising applications in chiral recognition, optoelectronic devices and biomaterials. [9][10][11][12] Stimuli-responsive organogels are a kind of fascinating LMWGs in which the morphology of molecules is regulated by external stimuli, including light, [13,14] pH, [15,16] ions, [17,18] sound, [19,20] and so on.…”