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World Journal of Chemical Education, 2019, Vol. 7, No. 3, 216-224
Available online at http://pubs.sciepub.com/wjce/7/3/5
Published by Science and Education Publishing
Determination of the p/o-Isomer Product Ratios in
Electrophilic Aromatic Nitration of Alkylbenzenes
Using High Resolution 1H NMR Spectroscopy
Michelle K. Waddell, Charles M. Bump, Edmund M. Ndip, Godson C. Nwokogu*
Department of Chemistry and Biochemistry, Hampton University, Hampton, VA 23668, U.S.A.
*Corresponding author: firstname.lastname@example.org
Received June 25, 2019; Revised August 10, 2019; Accepted August 25, 2019
Abstract High resolution 1H NMR spectroscopy, an increasingly available instrumental method, is used in
undergraduate organic laboratory practice as a simpler alternative to gas chromatographic method for the direct
determination of the p/o ratios of the crude reaction product from the nitration of alkylbenzenes. The choice of
isopropylbenzene as a substrate illustrates that steric effect can be significant in controlling regioselectivity in
electrophilic aromatic substitution reactions.
Keywords: laboratory instruction, organic chemistry laboratory, electrophilic aromatic substitution, nitration of
aromatic compounds, regioselectivity, quantitative 1H NMR spectroscopy
Cite This Article: Michelle K. Waddell, Charles M. Bump, Edmund M. Ndip, and Godson C. Nwokogu,
“Determination of the p/o-Isomer Product Ratios in Electrophilic Aromatic Nitration of Alkylbenzenes Using
High Resolution 1H NMR Spectroscopy.” World Journal of Chemical Education, vol. 7, no. 3 (2019): 216-224.
Nitration of alkylbenzenes is a reaction used to
illustrate the concepts of regioselectivity, directing effects
and steric effects of substituents in electrophilic aromatic