I recently stumbled upon a free App for the iPad that I plan to introduce to my students during our upcoming organic unit. This is just the first topic that I am using the app for. There are many more uses for the App in a number of units. If you don't have iPads in your classroom, there is also a ChemTube3D website offering similar functionality.
As described on the "About" page, ChemTube3D is an app that
"…contains interactive 3D animations for some of the most important organic chemistry reactions covered in school, college and undergraduate degree courses. The 'Structure and Bonding' section contains some information about types of bonding with an interactive window providing a 3D visualization. The 'Organic Reactions' section contains some information about each reaction mechanism, followed by an interactive reaction scheme…"
Figure 1 - Menu items available for "Organic Reactions"
Figure 2 - Menu items available for "Structure and Bonding."
Screenshots from the "Simple SN2 reaction" animation.
Diagram 1 - Showing the mechanism with some curly arrows. Clicking on the reaction arrow in the reaction diagram below the model will generate an animation of the nucleophilic attack, formation of the transition state, then the products.
Diagram 2 - Showing the transition state. The animation described above is great - but each step can be shown as a static image as well.
Diagram 3 - Showing the products of the substitution, with the sterochemistry inverted. This example is obviously not chiral, but the animation certainly allows students to consolidate their understanding of how this would matter for a chiral molecule.
MORE TO EXPLORE
What is not shown above is a brief animation of the process, from reactants to products - showing the transition state along the way. The real benefit that I can envision is the ability to move the models around on the screen and see the stereochemistry of the SN2 reaction. The inversion of the chiral carbon has always been difficult to show. Some textbooks, for example, use a diagram of an umbrella being inverted to show the stereochemistry but I have always found that analogy to be lacking a bit. With this app, my students will be able to manipulate an actual reaction and see the inversion themselves.
The variety of reactions is quite large - and certainly inclusive of most of the organic mechanisms I will be teaching in IB Chemistry. And the content available within "Structure and Bonding" is quite large as well. It also includes atomic and molecular orbitals with lots of examples, stereochemistry, and shapes of some molecules based on VSEPR.
Have a look at ChemTube3D and let me know what you think.