Deng S, Zhang Y, Brozena AH, Mayes ML, Banerjee P, Chiou WA, Rubloff GW, Schatz GC, Wang Y. Confined propagation of covalent chemical reactions on single-walled carbon nanotubes.
Nat Commun 2011;
2:382. [PMID:
21750536 DOI:
10.1038/ncomms1384]
[Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 06/09/2011] [Indexed: 11/09/2022] Open
Abstract
Covalent chemistry typically occurs randomly on the graphene lattice of a carbon nanotube because electrons are delocalized over thousands of atomic sites, and rapidly destroys the electrical and optical properties of the nanotube. Here we show that the Billups-Birch reductive alkylation, a variant of the nearly century-old Birch reduction, occurs on single-walled carbon nanotubes by defect activation and propagates exclusively from sp(3) defect sites, with an estimated probability more than 1,300 times higher than otherwise random bonding to the 'π-electron sea'. This mechanism quickly leads to confinement of the reaction fronts in the tubular direction. The confinement gives rise to a series of interesting phenomena, including clustered distributions of the functional groups and a constant propagation rate of 18 ± 6 nm per reaction cycle that allows straightforward control of the spatial pattern of functional groups on the nanometre length scale.
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