In This Issue

• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 73, Nº 6 (June), 1996, págs. 480-480
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Organic Chemistry--New Challenges Perhaps more than any other of the chemical subdisciplines, the scope and focus of organic chemistry has been changed by modern technology and theoretical advances, and these changes have had an equally striking effect on the undergraduate curriculum. The main challenge in organic chemistry classes has shifted, in less than a generation, from memorizing all the groups, naming conventions, and classes of reactions to understanding complex interactions at the structural and electronic orbital level. As biochemistry and polymer chemistry have grown from being the purview of a few specialists to full-blown disciplines of their own, they have also migrated from interesting, but optional, chapters at the back of the book to separate courses in the curriculum. The availability of inexpensive instrumentation means undergraduates routinely use NMR and mass spec instead of melting points to identify their products. And the changes are continuing: segments of biochemistry are metamorphizing into molecular biology and polymer chemistry is finding interconnections with materials science. In fact, as our understanding of chemical reactions at molecular and electronic levels expands, it becomes more and more difficult to decide on demarcations between the subdisciplines. Organic chemistry is an organizational construct that once was useful for segregating certain topics into a coherent two-semester introductory course. Today, it covers so much territory that no one who is an "organic chemist" can know even a small fraction of the territory and faces unique challenges when designing and teaching undergraduate courses. In a wide spectrum of articles in this issue that fall under the "organic" umbrella--from environmental chemistry to new polymer products--teachers share their specific experiences and creative solutions to these challenges, providing their colleagues with new ideas, processes, and pedagogic approaches.

    To start off, we can examine where it all started: benzene. Warnhoff (page 494) shows how the 19th century investigations of benzene and cyclohexane were intertwined. An article such as this gives a unique perspective on the development of organic chemistry and reveals how far it has come--some of the most famous chemists of that time spent a significant portion of their careers in settling issues that are now covered in a few brief paragraphs of an introductory text but which establish the foundations for all subsequent work. In the organic laboratory, the first revolution was Wohler's synthesis of a natural compound--urea--from inorganic compounds. Toth (page 539) has turned this famous reaction into a demonstration that will bring this seminal experiment off the history pages and into the classroom. Another demonstration, useful in either the general or organic class, has been designed by Pravia and Maynard (page 497) to illustrate why water and oil don't mix. Thall (page 481) gives his teaching colleagues some fascinating examples to use when teaching stereochemical concepts; "When Drug Molecules Look in the Mirror" they often see a stereoisomer with very different and interesting properties.

    Topics relating to polymer and biochemistry are being integrated into beginning courses, even at the secondary level, because of their importance in everyday life as well as being at the cutting edge of research. "Superabsorbent Polymers: An Idea Whose Time Has Come" by Buchholz (page 512) provides information about polymers with interesting properties that are finally finding a commercial application. Those teaching biochemistry will find Barmettler's summary of "Biochemical Data on the Web" (page 520) useful as well as experiments such as "Research in Undergraduate Instruction: A Biotech Lab Project for Recombinant DNA Protein Expression in Bacteria" by Brockman, Ordman, and Campbell (page 542); "A Simple Method for Isolation of Caffeine from Black Tea Leaves: Use of a Dichloromethane-Alkaline Water Mixture as an Extractant" by Onami and Kanazawa (page 556); and "The Analysis of Riboflavin in Urine Using Fluorescence" by Henderleiter and Hyslop (page 563).

    For the general undergraduate organic laboratory a wide range of topics and techniques are represented by "Epoxidation of Alpha-Methylstyrene and Its Lewis Acid Rearrangement to 2-Phenylpropanal" by Garin, Gamber, and Rowe (page 555); "Use of Gas Chromatography-Mass Spectroscopy (GC-MS) in Nonscience Major Course Laboratory Experiments" by Kostecka, Lerman, and Angelos (page 565); "Examination of a Reaction Mechanism by Polarimetry" by Mosher, Kelly, and Mosher (page 567); and "GS-MS and GC-FTIR Characterization of Products" by Amenta, DeVore, Gallaher, Zook, and Mosbo.

    Undergraduate laboratories are using more and more microscale experiments. The Microscale Laboratory feature brings new ideas regularly; this month features "Preparation and Properties of a Stable Organic Cation" by Manfredi and McGrew (page A124). Another microscale experiment "1H NMR Analysis of R/S Ibuprofen by the Formation of Diastereomeric Pairs" is provided by Sen and Aniker (page 569).