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David A Britz

Publications and source records attributed to David A Britz.

8 recordsLinked to original sources
PubMed2006

Synthesis and reactivity of N@C60O.

The endohedral fullerene epoxide N@C60O was synthesised, isolated by High Performance Liquid Chromatography (HPLC), and characterised by Electron Spin Resonance (ESR). This nitrogen radical displays predominantly axial symmetry characteristics as expected for a monoadduct, evidenced by a zero-field splitting D parameter of 6.6 MHz and an E parameter of 0.5 MHz in powder at 77 K. Photo- and thermally-activated silencing of the nitrogen radical were observed, the latter showing the evolution of a new spin signal during heating at 100 degrees C. We suggest that loss of nitrogen spin is due to coupling with a radical formed by opening of the epoxide ring. This implies that the reaction of C60O with C60 in the solid state proceeds via a radical, rather than ionic, intermediate.

Journal Article↗
PubMed2006

Noncovalent interactions of molecules with single walled carbon nanotubes.

In this critical review we survey non-covalent interactions of carbon nanotubes with molecular species from a chemical perspective, particularly emphasising the relationship between the structure and dynamics of these structures and their functional properties. We demonstrate the synergistic character of the nanotube-molecule interactions, as molecules that affect nanotube properties are also altered by the presence of the nanotube. The diversity of mechanisms of molecule-nanotube interactions and the range of experimental techniques employed for their characterisation are illustrated by examples from recent reports. Some practical applications for carbon nanotubes involved in non-covalent interactions with molecules are discussed.

Adsorption↗
PubMed2005

Molecules in carbon nanotubes.

This Account focuses on structural and dynamic behavior of molecules encapsulated in carbon nanotubes. The impact of the confinement on the molecular packing, orientation, translation, rotation, and reactivity is demonstrated for a range of fullerene and nonfullerene molecules. These phenomena are described and analyzed using the current understanding of molecule-nanotube and intermolecular interactions.

Journal Article↗
PubMed2004

Observation of ordered phases of fullerenes in carbon nanotubes.

We have assembled molecular arrays of C60 inside double-walled carbon nanotubes (DWNTs) with internal diameters of 11-26 A and directly observed the existence of different crystalline phases of C60 previously predicted theoretically. The structure of the encapsulated C60 crystal is defined by the internal diameter of the DWNT, as the molecules adjust their packing arrangement in order to maximize van der Waals interactions. We have also shown that fullerenes in C(60)@DWNT interact with the outer layer of DWNTs, as demonstrated by the efficient filling of DWNTs with internal diameters of less than 12 A.

Journal Article↗
PubMed2003

Selective host-guest interaction of single-walled carbon nanotubes with functionalised fullerenes.

Exohedrally functionalised fullerenes have been inserted in single-walled carbon nanotubes (SWNTs) with the aid of supercritical carbon dioxide to form peapods; C(61)(COOEt)(2) are encapsulated in SWNTs in high yield, whereas C(61)(COOH)(2) aggregate via hydrogen bonding to form a supramolecular complex, which sterically hinders encapsulation and causes it to adhere to the exterior surface of the SWNTs.

Journal Article↗