MATSUBARA Shizuo National Institute for Education, Chemistry Education, Chief Division, 科学教育センター, 室長 (50132692)
IKUO Akira Tokyo Gakugei University, Faculty of Education, Assistant Professor, 教育学部, 助手 (50159589)
|Budget Amount *help
¥2,400,000 (Direct Cost : ¥2,400,000)
Fiscal Year 1999 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1998 : ¥1,900,000 (Direct Cost : ¥1,900,000)
1. A chemical equation itself is not going to tell us the reason "why" a particular chemical reaction proceeds. It is our aim to produce a teaching material to make students marvel at chemical reactions and experience the joy of discovering the "why" of these reactions. Chemical reaction aminations were produced based on quantum chemical calculations. We call these animations "The Computer Microscope" and is available as a CD-ROM.
2. We chose molecules from high school textbooks, and by using these molecules we focused our study on a method of presentation which can help students understand or discover for themselves various reaction pathways. The animation we have produced are the following : (1) reaction of water and carbon dioxide, (2) reaction of water and sulfur trioxide, (3) reaction of water and dinitrogen tetroxide, (4) reaction of water and phthaic anhydride, (5) reaction of acetic acid and aniline.
3. The transition state of reaction is determined by using Gaussian 98, non empi
rical molecular orbital program package, and the reaction path is determined based on the intrinsic reaction coordinate theory. The animation depicts the molecular structure of each reaction step in such a way that the bond-order of each atom is displayed by the thickness of the "cylindrical bond" so that the thicker a bond, the stronger it is. In order to make a preliminary version, MOPAC, empirical molecular orbital program package, and CAChe, modeling software were used.
4. The computer screen displays a graph of the reaction profile, a curve representing the relationship between potential energy and the intrinsic reaction coordinate (IRC), and by means of blinking light along the curve, shows the current state of the reaction. By clicking on the IRC control bar at the bottom of the screen, students can manipulate the reaction animation manually. This has proven to be very popular with test students because they felt as if they were actually able to manipulate these reactions by hand.
5. The approaching path and geometry of the two molecules to be reacted are limited by the reaction path defined by the IRC theory. In order to ease observation of approaching molecules, the computer screen is divided into two ; the upper window shows the view from the top, and the lower window shows the view from the side. Presently, we are studying the methods for rotating molecules in 3D that may provide better understanding of the geometry of molecules being reacted. Less