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The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 12
Issue 5 (2007) pp 338-342
Complete Proton and Carbon Assignment
of Triclosan via One- and Two-Dimensional Nuclear Magnetic Resonance
Analysis
Kimberly A. Wilson and John J. Beck*
Department of Chemistry, Sweet Briar College, Sweet
Briar,
VA 24595, jbeck@pw.usda.gov
Received April 22, 2007. Accepted July 1, 2007.
Published online: 10 September 2007
Abstract. Students from an upper-division undergraduate spectroscopy class analyzed one- and two-dimensional 400-MHz NMR spectroscopic data from triclosan in CDCl3. Guided assignment of all proton and carbon signals was completed via 1D proton and carbon, distortionless enhancement by polarization transfer (DEPT) 135, 1H-1H correlation spectroscopy (COSY), 1H-13C heteronuclear single quantum coherence (HSQC), and 1H-13C heteronuclear multiple bond coherence (HMBC) NMR experiments. The near-symmetry of this diaryl ether provided a challenging structure elucidation problem for early-semester undergraduate spectroscopy students. Experimental 1H and 13C NMR chemical shifts are compared to estimated chemical shifts from computer software.
Key Words: Laboratories and Demonstrations; analytical chemistry; hands-on learning; NMR; organic; upper-division undergraduates
(*) Corresponding author. (E-mail: jbeck@pw.usda.gov)
Article in PDF format (471 KB) HTML format
Supporting Materials:
The following supporting material for this article is available: table of contents; 1H and 13C 1D and 2D NMR spectroscopic material used for this project; ChemDraw estimates for proton and carbon chemical shifts, a student worksheet that includes brief descriptions of select NMR experiments and large, numbered structures of triclosan. All supplementary NMR spectroscopic materials are scanned images of actual printed spectroscopic material. This material can be downloaded in a Zip file. (583 KB).Issue date: October
1, 2007
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