Differential Identification of Six “Mystery” Substances Using Three Distinct Analytical Techniques in a Forensic Science Laboratory

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 21 (2016) pp 119-128

The Use of a Small Chalcone Spectroscopy Database for the Introduction of Advanced Spectroscopy Techniques at the Undergraduate Levels

Chloe A. N. Gerak^†, Mathew L. Sutherland^†, Mackenzie J. Field^†, Esther H. S. Woo^†, Matthew R. Luderer^‡, and Nabyl Merbouh^†,*

^†Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada, nmerbouh@sfu.ca; ^‡Department of Natural Science, Mathematics, and Engineering, University of Pittsburgh at Greensburg, Greensburg, PA, 15601, USA
Received December 11, 2015. Accepted January 9, 2016.

Published: 20 June 2016

Abstract. Teaching organic spectroscopy and structure elucidation at the undergraduate level (IR, UV, NMR spectroscopy and mass spectrometry) often requires the use of ideal targets and flawless spectra, which can mislead students about the use of spectroscopy to solve every given structure. It is common for undergraduate students to use NMR spectroscopy to solve their unknown structures while discarding simpler analytical tools or methods. Substituted chalcones proved to be the perfect targets to teach students that NMR spectroscopy may not always be the definitive tool to analyze and identify a structure and that the knowledge of the uses and limitations of other spectroscopic methods is critical when trying to solve a problem. In this article, we have synthesized a series of mono- and disubstituted chalcones to be used as teaching examples for undergraduate students. This article teaches unequivocal structure identification and spectra assignment using IR, UV, NMR “full packages” and mass spectrometry, while supplying students with a large database of practice questions.

Key Words: Laboratories and Demonstrations; organic chemistry; chalcone, Nuclear Magnetic Resonance, Mass spectrometry, structure elucidation

(*) Corresponding author. (E-mail: nmerbouh@sfu.ca)

Article in PDF format (511 KB) HTML format

Supporting Materials:

All 1D and 2D NMR spectra with enlarged relevant regions, along with the IR and the EI-MS spectra are available to students and instructors in the supporting material section of this paper as pdf files. (5.28 MB)