Reinforcing the "Heath and Wellness" theme of National Chemistry
Week 2004, the featured molecules for this month are all found in commercial
sunscreens, or in the synthesis of sunscreen materials. The paper by Stabile
and Dicks introduces students of organic chemistry to the synthesis
of cinnamate esters used in sunscreen products. Several of the papers referenced
by those authors, most notably a paper by Doris Kimbrough (J.
Chem. Educ. 1997, 74, 51–53),
present the structures of additional sunscreen components.
Although the details of the synthesis are beyond the scope of most introductory
courses, these molecules present an excellent opportunity for introducing
students to the absorption of radiation that is far more relevant to
their lives than the line spectra of hydrogen and other atoms. Such a
discussion could be extended to include more delocalized dyes such as
those frequently studied in physical chemistry courses as a test of particle-in-a-box
models, and students could be asked about those molecules as sunscreens,
which raises an interesting intersection between aesthetics and spectroscopy.
In addition to the static image, two fully manipulable versions (Jmol, MDLChime) of these molecules appear below. (The Jmol versions may take a few extra seconds to load, based on the speed of your Internet connection.)
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