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The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 6
Issue 3 (2001) pp 142-146
An Organization Device for Visualizing Mechanisms and Regiochemistry Rationales in Electrophilic Aromatic Substitution
Donna J. Nelson
Department of Chemistry and Biochemistry, University of Oklahoma, Norman,
OK 73019
Received October 1, 2000. Accepted January 1, 2001
Published online: 23 March 2001
Abstract. Design and
testing of a hand-held device, consisting of two sheets of card stock,
presenting electrophilic aromatic substitution (EAS) data in an organized
fashion, and designed to facilitate learning electrophilic aromatic substitution
reactions is reported. The device includes a large amount of information
with similar data grouped, and the groups are juxtaposed in order to facilitate
pattern recognition and differentiation. This, in turn, facilitates visualization,
retention, understanding, and use of the data presented. One sheet is
placed over the other in order to visualize the mechanism between the
substituted aromatic compound selected and the chosen reagent. It shows
two aspects of EAS on separate pages and, then, demonstrates interactively
how they interrelate. The two aspects are (1) the substitution itself,
including the identity of the electrophile, the reagent(s) needed to generate
it, and the substituent in the product and (2) the electronic effects
of the groups in the aromatic compounds upon the intermediate(s) and the
structure of the product. The effect of the use of the Electrophilic Aromatic
Substitution Tool (also known as EAS-at-a-Glance) on the test performance
of students enrolled in undergraduate organic chemistry was determined
by a post-test-only control-group study. The subject samples were assigned
to a control group and three device groups, differing with respect to
use of the device. Results show that the EAS Tool enabled a better student
performance (by 12.3% to 17.3%, depending upon the method of use), and
that the best method of use is as an out-of-class supplement.
Key Words: In the Classroom; organic chemistry; electrophilic
(*) Corresponding author. (E-mail: DJNelson@chemdept.chem.ou.edu)
Article in PDF format (450 KB) HTML format
Issue date: June 1, 2001
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