Students construct computer models of two transition metal complexes, solve their electronic structures, and inspect the resulting d-type molecular orbitals to identify which are non-bonding, sigma* antibonding, or pi* antibonding. After constructing a molecular orbital diagram, they determine which of the two complexes is likely to absorb light at a longer wavelength.
Students should be able to
- carry out electronic structure calculations of transition metal cation complexes
- identify d-type orbitals within a transition metal complex
- explain the role of pi-antibonding orbitals in reducing the crystal field splitting
The exercise is designed to be run on a laptop with Spartan Student version 5.0.1
This learning object is the third in a series of Spartan-based modules in an integrated general chemistry course*. In the preceding two modules, students learn to interpret electrostatic potential mappings of molecules ("Intermolecular forces") and to interpret molecular orbitals ("The MO picture of bonding"). Thus, it is assumed for this activity that students come in already familiar with how to build molecules in Spartan, and how to interpret simple molecular orbitals and orbital diagrams.
*This course is directed at students who took a significant amount of high school chemistry (e.g. AP Chemistry). It is not assumed students have prior expertise in electronic structure calculations, however.