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The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 27
(2022) pp 82-86
Exploration of Factors Affecting the Relative Rate of Electrophilic Aromatic Bromination
Shanid Shrestha and Xiaolei Gao*
School of Natural Sciences, College of Natural, Behavioral and Health Sciences, Caldwell University, 120 Bloomfield Avenue, Caldwell, NJ 07006, xgao@caldwell.edu
Received July 25, 2021. Accepted January 21, 2022.
Published: 15 December 2022
Abstract. The experiments on the relative rates of bromination of different substituted aromatic compounds have been around in organic teaching labs for a long time. One major limitation with these experiments has been the lack of deactivating functional groups. The following experiment represents a new approach, which allows students to investigate the relative rate of not only activating but also deactivating substrates through experiment and deduction, which provides a more thorough view of the substituent effects on electrophilic aromatic substitution (EAS). The first part of the experiment focuses on activating group vs deactivating group, and how both the inductive and resonance effects of the different groups affect the rates. The second part then focuses on the additive effect of the two substituents on the aromatic ring by combining the deactivating and the activating groups from part I. Through logical deduction, the students are then able to determine the overall order of reactivity of all different functional groups.
Key Words: KW Laboratories and Demonstrations;,Organic Chemistry; Electrophilic Aromatic Substitution; Electrophilic Aromatic Bromination; Additive Effect; Active Learning
onding author. (E-mail: xgao@caldwell.edu)
Article in PDF format(173KB) HTML
Supplemental Material. A laboratory handout for students is included. 92KB
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