Kecking over Electron Counting Formalisms? An In-Class Exercise in Counting Electrons for Ru Complexes with Proton-Responsive Ligands in the CBC and Ionic Methods
Electron counting exercise motivated by a recent paper (J. Am. Chem.
Electron counting exercise motivated by a recent paper (J. Am. Chem.
In-class exercise that helps students learn how to use structural data and other experimental methods to assign structure. Using chemical intuition, students will rationalize the structures of metal complexes that differ by protonation states.
This 5 slides about outlines the basics of lanthanide photophysics as a primer for those new to the topic. These properties are very unique and actually very useful, which is a topic for another time. The intricacies of what causes the Ln luminescence, its strengths and drawbacks are discussed along with how these drawbacks are addressed in molecular complexes. Notes for the instructor are included that explain each slide.
In this literature discussion, students read an Inorganic Chemistry paper (doi: 10.1021/ic503062w) about diarylamido-based PNZ pincer ligands and their Ni, Pd, and Rh complexes. Specifically, this paper uses IR and E1/2 potentials to demonstrate that the redox events occur not on the metal center but on the pincer ligands.
This is a question based approach for a discovery activity about cyclic voltammetry. The slider bar on a movie can used to control a variable and the displayed graph is updated to show the results. (You could also just play the movie to get an idea of what changes.)
The questions to be answered are
What is the shape of a cyclic voltammogram?
How are cyclic voltammograms affected by E0?
How are cyclic voltammograms affected by concentration?
How are redox equilibria affected by scan rate?
What if there are two reductions?
This is a powerpoint presentation that was developed for and used at the 2016 VIPEr workshop on Organometallic chemistry at the University of Michigan. Organometallic chemistry is a broad field, and we have divided ourselves into different classes based on what we study. For example, the reactivity of the third row metals is often quite different from that of the fourth/fifth rows. Early (high oxidation state with anionic ligands typically) and Late (low oxidation state with neutral ligands typically) metal complexes have different properties and d electron counts.
This is an overview of some important principles of ligand design. Topics covered include HSAB theory, the chelate effect, the chelate ring size effect, the macrocyclic effect, the cryptate effect, and steric focus in ligand design.
Many extended structures can be viewed as close-packed layers of large anions, with the smaller cations fitting in between the anions. Larger holes between close-packed anions can hold cations with octahedral coordination. Smaller holes between close-packed anions can hold cations with tetrahedral coordination. The online jsmol resources show these layers and their holes.
This activity introduces students to fundamental types of organometallic reactions, and directs them to examine how each of these reactions affects the total electron count for the organometallic complex and the oxidation state of the central metal. Students are then directed to use these reactions to build a sequence of steps for a catalytic cycle.
This in-class worksheet introduces students to the different ways we describe organometallic ligands – bonding, properties, spectroscopy, etc. – using carbon monoxide as an example. It is structured as an inquiry-based activity, where students work together in small groups but check in with the entire class at appropriate intervals. I plan to use this activity with my advanced inorganic students next year.