Organic Chemistry involves reactions of molecules that have three dimensional structure. This subject is often difficult for students because they are not accustomed to thinking in a visual manner. Understanding the shapes of molecules and the reactions between them is greatly facilitated when students can "see" the molecules. Hand held molecular models can make this visualization process easier. Computer generated "models" can help bridge between the hand held models and the two dimensional representations we draw on paper. It is most important for students to be able to understand the two dimensional representations of chemical structures which chemists use to communicate about molecules and their reactions. My goal is to create a web site with tutorials and quizzes in order to guide students in this visualization process and enable them to make their own mental images of the structures and reactions we discuss in class.
Chemists convey three dimensional information about structures by using drawings with specialized symbols, which the reader must interpret. Computerized images may convey the same three dimensional information by making the images interactive. With molecular modeling software, the user can build and then rotate chemical structures to view them from different perspectives. Structures like these are then "embedded" into web pages in much the same way that other images are. These structural images are then viewed with Chemscape Chime, (http://www.mdli.com/chemscape/chime/chime.html) a browser plug-in which may be downloaded for free from MDL Information Systems (http://www.mdli.com/). Perhaps the most useful feature of this software for organic chemistry students is its ability to display animations of reactions. Unlike normal animations, these animated reactions may be manipulated in three dimensions, allowing a student to get a better perspective on how the chemical structures are changing as a particular reaction proceeds.
Many resources are available to assist students who are trying to learn organic chemistry. These resources include textbook ancillaries (solutions manuals, study guides, and CD-ROMs), as well as many sites on the World Wide Web. At Centre we normally make the textbook solutions manual/study guide available to students. For the past several years our organic students have used Spartan, a molecular modeling software that runs on Unix computers. Chemists routinely use molecular modeling software to make predictions about compounds before preparing them or to aid in their analysis of experimental results. Our students enjoy the opportunity to view and manipulate the images displayed by this software, but using unfamiliar software on a computer with a foreign operating system can be distracting to many students. Thus, a more effective teaching and learning strategy would be to make these computer generated images available to the students on the web rather than requiring them to use the molecular modeling software.
Until now my only use of the World Wide Web in organic at Centre involved a series of links to material developed at other institutions. The most straight forward solution to this visualization problem would be to use web-based materials that already exist. A couple of sites do use Chemscape Chime to show animations of reactions discussed in the organic course, see for example John Nash's animation of an SN2 Reaction at Purdue University (http://www.chem.purdue.edu/courses/chm116/anim/sn2.html), and Richard Johnson's animation of a Diels-Alder Reaction (http://pubpages.unh.edu/~rpj/dielsalder.html) at the University of New Hampshire. However, these sites do not provide the appropriate combination of structural information and text to be most effective for my students.My approach to using the World Wide Web in organic chemistry will focus on improving students' ability to visualize molecules by using Chemscape Chime's ability to display molecules interactively, along with text and buttons that activate scripts to highlight structural features or start and stop appropriate animations. This summer I am beginning to develop these tutorials along with interactive quizzes, with support from a Teagle Grant from Centre College. You may view my work in progress at http://jupiter.centre.edu/~muzyka.faculty.ed.centre/organic/organic.htm. I plan to target a series of topics which students have difficulty visualizing, rather than making my whole course web-based. My tutorial will cover: conformations of alkanes and cycloalkanes, stereochemistry, and nucleophilic substitution reactions.
I will make these tutorials and practice quizzes available to my students during the 1998-99 academic year. Students may like using this web-based tutorial, but the only real benefit will be if they gain the ability to make their own mental images of the structures. The American Chemical Society's standardized exam for organic chemistry is already used for the final exam in this course, so there is an existing mechanism to determine whether overall student learning in this course improves as students use this tutorial. I will monitor student scores with this standardized exam, and I will use that as well as student feedback to revise and improve the tutorials during the summer of 1999.
I am currently using PC Spartan from Wavefunction (http://www.wavefun.com/) as well as Tinker (http://dasher.wustl.edu/tinker/) to build and manipulate the chemical structures. I am also exploring other molecular modeling software (e.g., Hyperchem (http://www.hyper.com/) and Chem3D (http://products.camsoft.com/chem3d/)) to see if another program will be better suited to this task. Chime Resources (http://www.umass.edu/microbio/chime/index.html) by Eric Martz at University of Massachusetts, Amherst has been extremely valuable in helping me to learn how to embed Chemscape Chime objects in my HTML documents.
Last summer (1997) I attended the Mellon ACS Chemistry Workshop at the University of Richmond, and it has helped me see some of the capabilities of web-based teaching materials. This summer (1998), I attended the Web-deployable Educational Technologies Workshop (http://www.furman.edu/~treu/acs/98webdep/) at Furman University; this workshop introduced me to the nuts and bolts of using scripts in various ways, including interactive quizzes. Chime Resources (http://www.umass.edu/microbio/chime/index.html) by Eric Martz at University of Massachusetts, Amherst has been extremely valuable in helping me to learn how to implement Chemscape Chime information in my HTML documents.