Fullerenes peapods

The Raman spectra of C6o SWCNT peapods included features due to coupling of C60 totally symmetric modes with fullerene translational mobility within the tube.204 Raman data were reported for fullerene peapod species C60.C70 SWCNT.205 Raman spectra were also reported for the charge-transfer species C60 SWCNT and C70 SWCNT.206 207 High pressure resonance Raman spectra were reported for C60 and C70 peapods in SWCNT, at pressures of up to 9 GPa.208 Raman spectroscopy was used to follow the transformation of C60 peapods into SWCNT,209 and of C6o-SWCNT peapods into DWCNT.210... 

The Raman spectra of DWCNT s were analysed in terms of chiral, (n,m) assignments for these tubes.266 The Raman spectrum of I2-doped DWCNT gave assignments to radial breathing and tangential modes.267 Resonance Raman spectra of DWCNT were analysed to probe diameters and chiralities.268 The Raman spectra of DWCNT (from fullerene peapods annealed at high temperatures) show that the inner tubes are remarkably defect-free.269 Very low levels of defects were also observed from the Raman spectra of DWCNT produced by the catalytic decomposition of benzene over Fe-Mo/ A1203 catalysts at 900°C (i.e. very weak D-band at 1265.5 cm-1).270... 

Kavan, L. Dunsch, L. Kataura, H. Electrochemical tuning of electronic structure of carbon nanotubes and fullerene peapods. Carbon 2004, 42, 1011-1019. 

Kalbac, M., Kavan, L., Zukalova, M., and Dunsch, L. (2007) The in situ Raman spectroelectrochemical study of 13C labeled fullerene peapods and double walled carbon nanotubes. Small, 3, 1746-1752. 

Host-Guest Behavior of [lOJCPP-C o, o, Fullerene Peapod... 

Iwamoto T, Watanabe Y, Sadahiro T, Haino T, Yamago S (2011) Size-selective encapsulation of C60 by [lOjcycloparaphenylene formation of the shortest fullerene-peapod. Angew Chem Int Ed 50(36) 8342-8344... 

Immobilization of small proteins in MWNTs with 3.0-5.0nm in inner tube diameters was first observed with HRTEM in 1995 as mentioned in Sect. 2.4 [164,165]. CNTs were non-covalently hybridized with fuUerenes to provide fullerene peapods in 1998 [49,224], This novel nanomaterial attracted considerable attention because of the great possibility for tuning the electronic structures of CNTs and shielding the encapsulated molecules by the carbon cage [222],... 

More recently, a new frontier was opened up by filling single-walled carbon nanotubes with Cso to form the so-called fullerene peapods [23]. In 2003, Terrones et al. studied fullerene coalescence to a polyfullerene induced by electron irradiation on pristine nanotube peapods [24], paving the way to new highly conducting and semiconducting tubular structures with specific electronic characteristics (Figure 1.3). 

Bisporphyrin cleft molecule 25, which has dendritic wedges attached to the [60] fullerene molecules, forms an artificial peapod (Figure 9.26) [104]. [60]Fullerene is encapsulated within the cleft space provided by the two porphyrin components. As a result, the bisporphyrin cleft loses its conformational flexibility, and the two porphyrin units adopt a parallel arrangement, as in encapsulating [60]fullerene. This pre-organized structure assembles to produce a parallel array of the fullerene peapods. A fibrous morphology with a uniform diameter of 15nm is confirmed by TEM. 

Figure 9.26 Bisporphyrin 25 and fullerene peapod formed by self-assembly of 25 with [60]fullerene. (Reprinted with permission from Reference [104], Copyright (2003) American Chemical Society.)...

A detailed study of the C60/CNT system (named peapod , Fig. 3.15) was conducted, highlighting how the fullerene appears to be the perfect candidate for encapsulation, as a consequence of the similar graphitic scaffold, an ideal structural match between the C60 spherical shape and the internal CNT channels and strong van der Waals interactions [79]. 

Fig. 3.15 Schematic representation (top) and microscopy image (bottom) of the peapod system where fullerene molecules are encapsulated inside CNTs. Adapted with permission from [90], 2005, American Chemical Society.

Very recently author of this review successfully hydrogenated fullerenes inside of single walled carbon nanotubes (so called peapods). Evidence of hydrogenation was provided by NMR studies and Raman spectroscopy (Abou-Hamad et al. 2009). 

So far, direct evidence of C60 hydrogenation inside of nanotubes from HRTEM imaging is absent. It is required as a decisive demonstration of possibility for hydrogen to penetrate inside of peapods but could possibly be challenging experimentally. Chemical reaction within nanospace of carbon nanotubes is possibly only first example of interesting nanoscale chemistry and fullerene hydrogenation in other exotic environments will possibly be successfully demonstrated in future. It is quite likely that hydrogenation in confined space results in formation of fulleranes with different molecular structures. 

NEW ALLOTROPES OF CARBON GRAPHITE INTERCALATION COMPOUNDS, FULLERENES, FULLEROIDS, CARBON NANOTUBES, PEAPODS, AND GRAPHENE... 

Intercalation of fullerenes into nanotubes ("peapods") was discovered [93], and even endohedral fullerenes (e.g., Gd C82 inside SWCNT) [94,95]. A very rich chemistry was soon explored to bond C(,o covalently to disparate organic ligands (an early smorgasbord is shown in Fig. 12.13) [96]. 

Similar arguments like for the peapods hold for C ) surrounded by a belt-hke aromatic compounds (Figure 2.72a). Depending on their side chains the latter may confer some solubility in polar solvents. The interactions between belt and central fullerene are mainly of the ir-ji-type. They are exceptionally favorable due to the bent surface of both bonding partners. Inherently curved compounds tike perchlo-rotriquinacene can as well coordinate to by n-n interactions. 

Fullerenes—or cage compounds built exclusively from carbon atoms—and their metal-containing derivatives, metaUofuUerenes, were first observed in the gas phase by Kroto et al. [1,2] less than 20 years ago and prepared in crystalline form by Kratschmer et al. [3] less than 15 years ago. StiU, an enormous amount of observed and computed data has been obtained during this time (see, e.g. recent surveys on fullerenes [4-8] and endohedral metallofullerenes [9,10]). In addition to spheroidal fullerene cages, fullerene science also deals with other objects like elongated cylindrical bodies known as nanotubes, prepared by lijima [11] soon after mastering the fullerene synthesis, nanocones [12] or peapods [13]. AU the species exhibit a substantial application potential, especially for molecular electronics [14]. 

FIGURE 1.8 TheFullereneCgo, a Fullerene Compound, a Carbon Nanotube, Graphene, a Carbon Peapod, and a Polyyne "Wire" Connecting Platinum Atoms. 

Chan et al [52] 2011 Utilizing DonneU shell equilibrium equation and also Euler-Ber-nouUi beam equation incorporating curvature effect Various chairality — — Investigating pre and post-buckling behavior of MWCNTs and multi-walled carbon nano peapods considering vdW interactions between the adjacent walls of the CNTs and the interactions between the fullerenes and the inner wall of the nanotube... 

L. (2007) The change of the state of an endohedral fullerene by encapsulation into SWCNT a Raman spectroelectro-chemical study of Dy3N C80 peapods. Chem. A Eur. /., 13, 8811-8817. 

Su HB et al (2007) Simulations on the effects of confinement and Ni-catalysis rai the formation of tubular fullerene structures from peapod precursors. Phys Rev B 75(13) 134107-(5)... 

Cso peapods, C50 encapsulated inside a CNT, were first produced and observed during CNT synthesis by pulsed laser vaporization [150]. Nowadays the synthesis of encapsulated fullerenes [151], endohedral fullerenes [71,151-156] and volatile organometallic complexes of fullerenes [157] within the CNTs is mainly achieved by vapor phase filling technique, consisting in heating at the... 

Very interesting supramolecular structures are known as carbon peapods, and consist of single-walled carbon nanotubes (SWCNTs) filled with fullerenes. After their first detection via high-resolution transmission electron microscopy (HRTEM) as a side product in the production of carbon nanotubes, different methodologies have been developed to produce such new carbon allotropes. The harsh conditions previously used (such as high temperatures, low pressures, and acidic medias) have been later overcome by mild condition experiments that exploited not completely understood mechanisms of nano-condensation and nanoextraction. ... 

It was shown how both endohedral and exohedral fullerenes can be inserted in nanotubes. In the peapods containing endohedral fullerenes (for instance Ce Cg2), HRTEM images showed interesting rotation and translation motion of the trapped spheroids. Exohedral metallofullerenes, CsC io have been synthesized and successfully encapsulated into SWCNTs via a new chemical reduction of Cgo molecules into anions. The addition of iodine to already prepared peapods allowed the coalescence of Cgo directly inside the nanotubes. Indeed, after heating at 550 C, iodine-doped peapods, inside the Cgo molecules molecules have been transformed in a tubular structure. Khlobystov et al. were able to perform reactions on the inner surface of carbon nanotubes in the presence of catalyti-cally active atoms of rhenium and monitor the whole process via HRTEM. ... 

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