Chemistry for Everyone edited by
JCE Featured Molecules
William F. Coleman Wellesley College Wellesley, MA 02481
The Chemistry of Coffee August Featured Molecules The paper by Marino Petracco (pages 1161–1167) provides a hearty blend of molecules for this month. The author deals with coffee at a number of different levels ranging from the economic and social to the still perplexing questions of flavor and aroma. The associated molecules demonstrate a range of structural features that students will benefit from examining in three dimensions. Students encountering chemistry for the first time are often dismayed and confused by the range of shorthand representations that we use to convey structural information. Nicotinic acid, for example, is drawn, in the paper and in essentially all other print sources, as a regular hexagon. Stu-
chlorogenic acid
www.JCE.DivCHED.org
trigonelline
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dents should rightly ask how accurate that representation is, and should be encouraged to use the structure file to measure the relative bond lengths to see the deviation of the actual structure from one with six equal-length sides. The paper also serves as a rich source of student projects in high school and introductory college courses. Students might be asked to pick one of the aroma producing molecules, find other foods containing that molecule, and look for possible trends. Fully manipulable (Chime) versions of these and other molecules are available at the Only@JCE Online Web site: http://www.JCE.DivCHED.org/JCEWWW/Features/ MonthlyMolecules/2005/Aug
nicotinic acid
Vol. 82 No. 8 August 2005
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2,4,6-trichloroanisole
Journal of Chemical Education
1167
