Formation of Carbon Nanotube Based Gears: Quantum Chemistry and
Molecular Dynamics Simulations of the Electrophilic Addition of o-Benzyne
to Fullerenes, Graphene, and Nanotubes.
Richard Jaffe, NASA Ames Research Center and
Jie Han and Al Globus, MRJ, Inc. at NASA Ames Research Center.
In accompanying papers [Han 96, Globus 96], the structure, operation, and
properties of hypothetical nanotube-based molecular gears are described. These
gears are single-walled carbon nanotubes with appended o-phenylene groups
to serve as teeth. One possible synthetic route for the formation of these
gears is the electrophilic cycloaddition of o-benzyne to the
nanotube. This reaction is known to occur under mild conditions with
planar molecules such as naphthalene and anthracene [Hoffmann, 67] and
fullerenes like C60 [Hoke 92]. In the present study we consider the pathways
for o-benzyne addition to naphthalene, C60, and a model curved polycyclic
aromatic hydrocarbons chosen to represent the carbon nanotube used in the gear
simulations [Han 96]. We use Density Functional Theory (DFT), a variant of ab
initio quantum chemistry,
and molecular mechanics and dynamics calculations for this study. The molecular
mechanics calculations are carried out using the potential energy force field
developed by Brenner [Brenner 90].
The relative heats of reaction and reaction pathways are
examined in an effort to determine whether this synthetic approach is feasible
for the addition of o-phenylene groups to carbon-based nanotubes. In addition,
we assess the suitability of the Brenner potential energy formulation for
use in the companion molecular dynamics simulations [Han 96].
To the full paper.
To companion papers.
Web Work: Al Globus