title: Simultaneous discrimination of diameter, handedness, and metallicity of single-walled carbon nanotubes with chiral diporphyrin nanocalipers.
abstract: We have been developing the methodology to discriminate the handedness and diameter of single-walled carbon nanotubes (SWNTs) through molecular recognition using chiral diporphyrin nanotweezers. Although relatively small diameters of SWNTs (<1.0 nm) were recognized well, nanotweezers were not able to form stable complexes with the SWNTs having the diameters >1.0 nm. In this context, we designed chiral diporphyrin with a much larger cavity, namely, "nanocalipers". The feature of the newly designed host molecule is: (1) long spacer with more than 1.4 nm consisting of three aromatic moieties; (2) nearly parallel orientation of the two porphyrins; (3) restricted conformation by biaryl linkages of the porphyrin-carbazole and carbazole-anthracene; (4) strong interaction of two porphyrins and anthracene with the surface of a SWNT through π-π stacking; and (5) stereogenic centers at the periphery of porphyrins discriminating helicity of SWNTs. As expected, we obtained optically active SWNTs with >1.0 nm in diameter and, unexpectedly, enriched metallic SWNTs over semiconducting ones. The optically active metallic SWNTs are identified for the first time, in addition to the optically active semiconducting SWNTs with such large diameters. The nanocalipers are found to recognize the diameter, handedness, and metallicity of SWNTs simultaneously.
authors: Department of Chemistry, Shiga University of Medical Science, Seta, Otsu 520-2192, Japan.
authors: Gang
authors: G
authors: Liu
authors: Feng
authors: F
authors: Wang
authors: Songpol
authors: S
authors: Chaunchaiyakul
authors: Yukie
authors: Y
authors: Saito
authors: Ajoy K
authors: AK
authors: Bauri
authors: Takahide
authors: T
authors: Kimura
authors: Yuji
authors: Y
authors: Kuwahara
authors: Naoki
authors: N
authors: Komatsu
mesh_terms: D000873:Anthracenes / Q000737:chemistry; D002227:Carbazoles / Q000737:chemistry; D007536:Isomerism; D008670:Metals / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D011166:Porphyrins / Q000737:chemistry*
chemical_list: D000873:Anthracenes; D002227:Carbazoles; D008670:Metals; D037742:Nanotubes, Carbon; D011166:Porphyrins; C041514:carbazole; C034020:anthracene