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Title: Unraveling the 13C NMR Chemical Shifts in Single-Walled Carbon Nanotubes: Dependence on Diameter and Electronic Structure

Abstract

The atomic specificity afforded by nuclear magnetic resonance (NMR) spectroscopy could enable detailed mechanistic information about single-walled carbon nanotube (SWCNT) functionalization as well as the noncovalent molecular interactions that dictate ground-state charge transfer and separation by electronic structure and diameter. However, to date, the polydispersity present in as-synthesized SWCNT populations has obscured the dependence of the SWCNT {sup 13}C chemical shift on intrinsic parameters such as diameter and electronic structure, meaning that no information is gleaned for specific SWCNTs with unique chiral indices. In this article, we utilize a combination of {sup 13}C labeling and density gradient ultracentrifugation (DGU) to produce an array of {sup 13}C-labeled SWCNT populations with varying diameter, electronic structure, and chiral angle. We find that the SWCNT isotropic {sup 13}C chemical shift decreases systematically with increasing diameter for semiconducting SWCNTs, in agreement with recent theoretical predictions that have heretofore gone unaddressed. Furthermore, we find that the {sup 13}C chemical shifts for small diameter metallic and semiconducting SWCNTs differ significantly, and that the full-width of the isotropic peak for metallic SWCNTs is much larger than that of semiconducting nanotubes, irrespective of diameter.

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Science, Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, Solar Photochemistry Program
OSTI Identifier:
1039100
Report Number(s):
NREL/JA-5900-54753
Journal ID: ISSN 0002-7863; JACSAT; TRN: US201209%%163
DOE Contract Number:  
AC36-08GO28308
Resource Type:
Journal Article
Journal Name:
Journal of the American Chemical Society
Additional Journal Information:
Journal Volume: 134; Journal Issue: 10; Journal ID: ISSN 0002-7863
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 77 NANOSCIENCE AND NANOTECHNOLOGY; CARBON; CHEMICAL SHIFT; ELECTRONIC STRUCTURE; NANOTUBES; NUCLEAR MAGNETIC RESONANCE; SPECIFICITY; SPECTROSCOPY; ULTRACENTRIFUGATION; nuclear magnetic resonancy; NMR; single walled carbon nanotube; SWCNT; parameters; diameter; electronic structure

Citation Formats

Engtrakul, Chaiwat, Irurzun, Veronica M., Gjersing, Erica L., Holt, Josh M., Larsen, Brian A., Resasco, Daniel E., and Blackburn, Jeffrey L. Unraveling the 13C NMR Chemical Shifts in Single-Walled Carbon Nanotubes: Dependence on Diameter and Electronic Structure. United States: N. p., 2012. Web. doi:10.1021/ja211181q.
Engtrakul, Chaiwat, Irurzun, Veronica M., Gjersing, Erica L., Holt, Josh M., Larsen, Brian A., Resasco, Daniel E., & Blackburn, Jeffrey L. Unraveling the 13C NMR Chemical Shifts in Single-Walled Carbon Nanotubes: Dependence on Diameter and Electronic Structure. United States. doi:10.1021/ja211181q.
Engtrakul, Chaiwat, Irurzun, Veronica M., Gjersing, Erica L., Holt, Josh M., Larsen, Brian A., Resasco, Daniel E., and Blackburn, Jeffrey L. Wed . "Unraveling the 13C NMR Chemical Shifts in Single-Walled Carbon Nanotubes: Dependence on Diameter and Electronic Structure". United States. doi:10.1021/ja211181q.
@article{osti_1039100,
title = {Unraveling the 13C NMR Chemical Shifts in Single-Walled Carbon Nanotubes: Dependence on Diameter and Electronic Structure},
author = {Engtrakul, Chaiwat and Irurzun, Veronica M. and Gjersing, Erica L. and Holt, Josh M. and Larsen, Brian A. and Resasco, Daniel E. and Blackburn, Jeffrey L.},
abstractNote = {The atomic specificity afforded by nuclear magnetic resonance (NMR) spectroscopy could enable detailed mechanistic information about single-walled carbon nanotube (SWCNT) functionalization as well as the noncovalent molecular interactions that dictate ground-state charge transfer and separation by electronic structure and diameter. However, to date, the polydispersity present in as-synthesized SWCNT populations has obscured the dependence of the SWCNT {sup 13}C chemical shift on intrinsic parameters such as diameter and electronic structure, meaning that no information is gleaned for specific SWCNTs with unique chiral indices. In this article, we utilize a combination of {sup 13}C labeling and density gradient ultracentrifugation (DGU) to produce an array of {sup 13}C-labeled SWCNT populations with varying diameter, electronic structure, and chiral angle. We find that the SWCNT isotropic {sup 13}C chemical shift decreases systematically with increasing diameter for semiconducting SWCNTs, in agreement with recent theoretical predictions that have heretofore gone unaddressed. Furthermore, we find that the {sup 13}C chemical shifts for small diameter metallic and semiconducting SWCNTs differ significantly, and that the full-width of the isotropic peak for metallic SWCNTs is much larger than that of semiconducting nanotubes, irrespective of diameter.},
doi = {10.1021/ja211181q},
journal = {Journal of the American Chemical Society},
issn = {0002-7863},
number = 10,
volume = 134,
place = {United States},
year = {2012},
month = {3}
}