Submitted by Chip Nataro / Lafayette College on Tue, 08/26/2025 - 13:34
My Notes
Categories
Prerequisites
First Semester Inorganic Chemistry / Foundation Course in Inorganic Chemistry
General Chemistry
Corequisites
No Corequisites
Course Level
Second year
Upper Division/Graduate
Topics Covered
Bonding models: Discrete molecules
Chemical literature
Computer modeling
Coordination chemistry
Electronic spectroscopy
Group theory & applications
Molecular structure
Organometallic chemistry
Physical methods / analytical techniques
Reaction mechanisms
Symmetry
Synthesis and reactivity
Thermodynamics
Subdiscipline
Coordination Chemistry
Molecular Structure and Bonding
Organometallic Chemistry
Spectroscopy and Structural Methods
Description

This literature discussion is in honor of Dr. Josh Figueroa, recipient of the 2026 F. Albert Cotton Award in Synthetic Inorganic Chemistry. Josh has done some tremendous work with isocyanide ligands and this paper is but a brief glimpse into this field. The complexes of interest contain carbonyl ligands and isocyanide ligands, so there are plenty of opportunities for students to use group theory to predict the number of IR-active vibrations for these ligands. There is a surprisingly small amount of electron counting that is presented using the CBC method. While there is ample NMR presented, the primary focus in this LO is on the 19F NMR spectra. The specific paper of interest can be found here.

Attachment Size
Questions for students 173.88 KB
Questions for students 712 KB
Learning Goals

Through completing this literature discussion, students will be able to

  • Use the CBC electron counting method to classify coordination compounds; determine the electron number, ligand bond number, metal valence, and dn count..
  • Use group theory and infrared data to determine which geometric isomers of various coordination complexes are formed.
  • Use 19F NMR data to determine which geometric isomers of various coordination complexes are formed.
  • Use molecular orbitals and explain the donor-acceptor nature of carbonyl and isocyanide ligands. 
Related activities
IR Spectroscopy of Rhodium Carbonyl Clusters
In-Class Review Questions for Metal Carbonyl Complexes
Molecular Structure - The Curious Case of Iron Tetracarbonyl
Electron Counting and CBC Assignments for Organometallic Complexes
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
More Electron Counting and CBC Assignments for Organometallic Complexes
Implementation Notes

I have not used this LO in class yet, but it might just be my first exam in my senior class in the fall of 2025. There is certainly more that could be talked about in this short paper. The supporting information presents the actual 19F spectra, and students could certainly gain a lot from that analysis as well as thinking about the 1H and 13C spectra NMR. I am going to be particularly interested to see how the students handle the misassignment of the IR data for one of the compounds. I think that will provide an interesting point for discussion as the mistake (I am confident it was inadvertent) got past not only the authors, but also the reviewers. 

Time Required
50 minutes at least
Web Resources
Paper from the Figueroa lab
Paper containing information on [Re(CO)6]+
Second paper containing information on [Re(CO)6]+
Evaluation
Evaluation Methods

Again, this has not been used in class yet. Once it is I hope to update this section.

Creative Commons License
Attribution, Non-Commercial, Share Alike CC BY-NC-SA