This LO grew out of my interest in understanding (deeply) the machinery behind the Evans method calculations. I did these calculations as a grad student to characterize my compounds, and I teach it in both my lecture and lab. Currently I use the metal acac synthesis lab to motivate the problem.
After I teach my students about magnetism and magnetic properties in coordination compounds, I spend a day showing how the data is collected and analyzed. I teach them about the Gouy balance, the Evans method of determining magnetism by NMR, and SQUID magnetometry. I also show them real data that I collected as an undergraduate or graduate student, and have them interpret and analyze it.
The only experiment that we can do locally is the Evans method, so I spend more time on this technique. We use the method during the metal acac laboratory.
This literature discussion focuses on a paper from the Angelici lab that examines the heat of protonation of [CpʹIr(PR3)(CO)] compounds. The compounds presented in the paper provide good introductory examples for electron counting in organometallic compounds. The single carbonyl ligand in these compounds provide an excellent probe to monitor the electron richness at the metal center which is impacted by the electron donor ability of the ligands.
The colors of transition metal compounds are highly variable. Aqueous solutions of nickel are green, of copper are blue, and of vanadium can range from yellow to blue to green to violet. What is the origin of these colors? A simple geometrical model known as crystal field theory can be used to differentiate the 5 d orbitals in energy. When an electron in a low-lying orbital interacts with visible light, the electron can be promoted to a higher-lying orbital with the absorption of a photon. Our brains perceive this as color.
Students work in groups to derive the ligand-field diagram for a square-pyramidal vanadium(III) oxo complex using octahedral V(III) as a starting point. The activity helps students to correlate changes in orbital energies as a function of changing ligands and geometry as well as rationalizing why certain geometries can be particularly good (or bad) for particular complexes. The activity also helps students see why oxo complexes of early metals are frequently best described as triple bonds.
I used this as an in class activity but it may work better as a problem set for your class. I had the students read the pertinent chapters of the textbook which go through symmetry and molecular vibrations, including using both stretches and cartesian axes as bases. In class, I divided the students up into four groups. Each group did one of the problems for 30 minutes and during the last 20 minutes of class, they reported out their solution. The students had not seen the Hooke’s law in the textbook so I included it as part of the activity.
This list includes a number of LOs to help in teaching nanomaterials subjects; however, it is not exhaustive.
Updated June 2018.
ColourLex (colourlex.com) is an amazing website that mixes chemistry and art. The creators of this website have extensively catalogued paintings and the pigments that were used to create them. The pigments range from artificial to natural and organic to inorganic. You can search for the specific combination that you want to see.
In this experiment, students will synthesize and characterize a series of Ru(II) p-cymene piano-stool complexes.
The Cambridge Crystallographic Data Centre (CCDC) provides many free programs that can be used to view and manipulate crystal structures. Additionally, they have made a subset of the Cambridge Structural Database (CSD) available for teaching purposes and many educational activities have been created to go along with this teaching subset (see link below). This teaching subset can be freely viewed through the WebCSD interface or can be used in the freely-available Mercury program. (Mercury is avaliable for Mac, Windows, and Linux systems.)