The Inorganic Illustrator: A 3-D Graphical Supplement for Inorganic and Bioinorganic Chemistry Courses Distributed on CD-ROM

The visualization of molecular and solid state chemical structures in three dimensions is a particularly difficult problem for students to overcome when the primary means of communication is the two-dimensional world of textbooks, blackboards, and overhead projector screens. Recent editions of popular textbooks in organic, inorganic, and biochemistry have included stereoviews of molecules to aid the student, and stereoviews of crystal structures have been used in inorganic chemistry publications for many years. These are powerful aids for visualizing complex molecules, but with the exception of the biochemistry text mentioned above, they are limited to single, static images generally in black and white. Molecular model kits are routinely used very effectively in organic chemistry but their utility in inorganic chemistry is limited to all but the most simple molecules encountered. Now that personal computers are generally accessible and multimedia tools are starting to make an appearance in chemistry lecture halls (1), we can make our inorganic and bioinorganic chemistry and crystallography lectures come alive with the aid of the computer-based resources, which are the essence of this project.

As part of this project we are accumulating a database of representative crystal structures of main group molecules, coordination complexes, organometallic compounds, small metalloproteins, bioinorganic model complexes, clusters, and solid state materials in Chem3D Plus format to be viewed with Chem3D Viewer, which is free software from Cambridge Scientific Computing. We are also generating a library of high-quality graphic images of these same molecules and structures using Cerius2 package from Molecular Simulations. These include polyhedral representations of clusters and solid state structures (see Fig. 1).

Figure 1. Representation of the user interface: the title page and an example of polyhedral and ball-and-stick representation of an octanuclear iron-oxo cluster.

The files of solid state structures will not be limited to single unit cells that are common in textbooks, but will present multiple cells such that the extended lattice of the material is evident. Navigation through these resources is through a unique open hypertext-based interface using Authorware, which allows the user to create complex applications that support movies, animation, and other graphics seamlessly.

Chem3D Viewer is a powerful program that allows not only multiple visualization modes, but also the detailed analysis of both bonded and nonbonded distances and angles. This is particularly useful for recognizing symmetry elements within molecules, as the student can precisely align atoms along the screen's Cartesian axes or within its planes and subsequently rotate the molecules about the axes at precise angles. We are developing stand-alone interactive tutorials to assign point groups to molecules and clusters. In addition, tutorials are being developed that show how the Chem3D Viewer software can be most effectively used in a classroom setting for lectures or for home or lab use by the students.

The Inorganic Illustrator will be made available to the education community for the cost of materials plus shipping and handling.

Acknowledgment

We would like to thank the NSF for financial support through the Division of Undergraduate Education Course and Curriculum Program (DUE-CCD 9455567).