Synthesis of corrugated C-based nanostructures by Br-corannulene oligomerization (original) (raw)
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Nanoscale, 2012
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Communications Chemistry, 2019
Corannulene (C 20 H 10) is a polycyclic hydrocarbon in which five six-membered rings surround a central five-membered ring to construct a bowl-like aromatic structure. Here we examine the development of synthetic strategies that allow for the growth of the peripheral aromatic rings as a means to extend the aromatic area of the central corannulene nucleus and provide access to unique nanocarbon molecules. s p 2-hybridised structures of carbon have fascinated the research community for a very long time. In 1985, buckminsterfullerene, otherwise known as C 60 , was discovered (Fig. 1a) 1. In this ball-shaped molecule, the curvature in the structure stems from the presence of fivemembered rings. In 1991, carbon nanotubes arrived on the scene 2. Here, the structure is cylindrical and composed of only rolled-up six-membered rings. In 2004, a sheet-like single layer from graphite-graphene-was isolated 3. All of these materials were shown to have extraordinary electronic and mechanical properties due to their unique curved or planar sp 2-hybridised aromatic structures. Inspired by these discoveries, chemists have been developing strategies to access such aromatic hydrocarbons through rational ('bottom-up') synthetic approaches. Scott's 12-step chemical synthesis of fullerene C 60 from a rationally designed precursor is a testament to the ingenuity and resourcefulness of organic chemists 4. In planar structures, nanographenes (well-defined cutouts of graphene with nano-scale dimensions) can now be prepared on a regular basis with a very diverse portfolio 5. It is expected that combining the planar structure of graphene with the curvature of fullerenes may produce hybrid materials with interesting properties 6-8. To induce non-planarity into nanographenes, a practical approach would be to introduce a fivemembered ring such as in the case of fullerene, C 60. A perfect building block that allows for such a structural arrangement to happen is corannulene (1)-a molecule in which five six-membered rings surround a central five-membered ring to give a bowl-like structure (Fig. 1b) 9-20. Corannulene also offers many beneficial features as a molecular building block. It has high solubility in common organic solvents. It can be derivatized in a well-defined manner. Due to synthetic ease, the derivatives can be prepared on a multigram scale. These attributes are important as they allow for the scalable preparation of carefully designed corannulene-based building blocks and the subsequent synthesis, purification and structural analysis of the larger (fused) aromatic systems. Recently, therefore, there has been a surge in employment of corannulene as a core molecule in the synthesis of extended aromatic structures. Our aim in this review article is to discuss
Recent Progress on the Synthesis and Applications of Carbon Based Nanostructures
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South African Journal of Science, 2011
Materials made of carbon that can be synthesised and characterised at the nano level have become a mainstay in the nanotechnology arena. These carbon materials can have a remarkable range of morphologies. They can have structures that are either hollow or filled and can take many shapes, as evidenced by the well-documented families of fullerenes and carbon nanotubes. However, these are but two of the shapes that carbon can form at the nano level. In this review we outline the types of shaped carbons that can be produced by simple synthetic procedures, focusing on spheres, tubes or fibres, and helices. Their mechanisms of formation and uses are also described.
Bulk synthesis of carbon nanostructures: Hollow stacked-cone-helices by chemical vapor deposition
Materials Research Bulletin, 2008
Bulk synthesis of hollow carbon stacked-cone-helices of diameter from 10 nm to 0.5 mm is reported. The fibres' walls are made up of parallel stacked-cone-like structures with an inter-cone distance from 3.38 to 3.5 Å. Apex angles observed are in the range from 308 to 1108, suggesting that the carbon nanofibres are constructed by a single graphene sheet which forms a helical structure instead of a stacked cone or open stacked cup structure. A new 3-D construction of the stacked-cone-helix is presented. Our results show that metal Pd catalyst plays a key role in obtaining carbon products with cone-helix structure and high yield (200%). These novel fibres could be used as nano-wire templates, micro-spray, and field emitters. #
Nanotechnology, 2001
Calculations using an analytic potential show that carbon nanocones can exhibit conventional cone shapes or can form concentric wave-like metastable structures, depending on the nanocone radius. Single nanocones can be assembled into extended two-dimensional structures arranged in a self-similar fashion with fivefold symmetry as system size is increased. Calculations of the electronic properties of nanocones indicate that a pentagon in the centre of a cone is the most probable spot for emitting tunnelling electrons in the presence of an external field. This implies that nanocone assemblies, if practically accessible, could be used as highly localized electron sources for templating at scales below more traditional lithographies.
Polymer–metal complexes as a catalyst for the growth of carbon nanostructures
Carbon, 2009
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Contributions to Plasma Physics, 2011
The aim of present paper is to present the latest results on investigations of the carbon thin film deposited by Thermionic Vacuum Arc (TVA) method and laser pyrolysis. X-ray photoelectron spectroscopy (XPS) and X-ray generated Auger electron spectroscopy (XAES) were used to determine composition and sp2 to sp3 ratios in the outer layers of the film surfaces. The analyses were