This in-class activity walks students through the preparation of a molecular-orbital diagram for methane in a square-planar environment. The students generate ligand-group orbitals (LGOs) for the set of 4 H(1s) orbitals and then interact these with carbon, ultimately finding that such a geometry is strongly disfavored because it does not maximize H/C bonding and leaves a lone pair on C.
Having been inspired by a number of wonderful LOs, I introduced group theory in my 'sophomore' inorganic class this spring. In addition to learning to determine the point group of a molecule, students were taught how to construct a qualitative MO diagram though the use of LGOs. While a little more than 5 slides, this is what I used in lecture to cover the material.
Having been inspired by a number of wonderful LOs, I introduced group theory in my 'sophomore' inorganic class this spring. In addition to learning to determine the point group of a molecule, students were taught how to construct a qualitative MO diagram though the use of LGOs. While this course can be taken with or without the laboratory component, it seemed only natural to include a lab on this material. A previous lab had introduced the students to computational methods for geometry optimization.
Two excellent video presentations on symmetry. The Ted Talk by Marcus du Sautoy is an excellent introduction to the concept of symmetry and systematically describing it. In "Impossible Crystals" Nobel Laureate and physicist Paul Steinhardt discusses the creation of "Impossible crystals": quasi-crystals with five-fold symmetry previously believed impossible.
This exercise was developed to help students predict bonding between s,p and d atomic orbitals.
This activity is meant to teach students an MO theory interpretation of hypervalency that goes beyond the simple (and somewhat unsatisfying) explanation that atoms that are in the third row and below use d-orbitals for bonding in addition to s- and p-orbitals. Specifically, students will be learning how to construct MO diagrams for multicenter bonding schemes (i.e., 3c4e).
This presentation provides a short introduction to Quantitative Structure-Activity Relationships and its use in Inorganic Chemistry. A brief introduction to Linear-Free Energy Relationships and the Hammett Equation is given, followed by three examples of how QSARs have been used in inorganic chemistry.
This in-class activity traces the many contributions leading to the correct assignment for the solid-state structure of triiron dodecacarbonyl, [Fe3(CO)12], with the aim of reinforcing ideas about IR spectroscopy and group theory. I give this activity to my advanced inorganic chemistry class (graduate students and senior undergrads). The activity is loosely based on the paper: Desiderato, R., Jr.; Dobson, G. R. J. Chem. Educ. 1982, 59, 752-756 and incorporates questions about symmetry and group theory for metal carbonyls.
Students work individually, then compete in teams, to identify symmetry elements and operations present in a high-symmetry structure, such as an octahedron or tetrahedron (without showing the character table until the end of the activity). Students often visualize symmetry elements differently from one another. Creating teams, allows them to work collaboratively, and the competition adds an incentive for finding the most elements. Since some students are better at seeing some symmetry elements (and operations) than others, it allows for them to work in small groups to both teach and lea
Chimera is a program for interactive visualization and analysis of molecular structures and related data, including density maps, supramolecular assemblies, sequence alignments, docking results, trajectories, and conformational ensembles. High-quality images and animations can also be generated. Chimera includes documentation and tutorials, and can be downloaded free of charge for academic, government, non-profit, and personal use. Chimera was developed at UCSF and was funded by the National Institute of Health.