Submitted by Wes Farrell / United States Naval Academy on Wed, 05/15/2024 - 14:34
My Notes

This is a literature discussion regarding electron counting.  It involves several opportunities for students to use CBC to determine electron counts themselves.  Then, it demonstrates the first case of a 21-electron complex, which leads to great discussion regarding the 18-electron rule.  Throughout the discussion, students are introduced to many structural and spectrochemical analyses, some of which may be new to them.

Attachment Size
Student Questions 20.14 KB
Learning Goals

Use CBC to perform electron counting

Learn to interpret structural and spectrochemical data to support assumptions made about bonding in CBC

Be exposed to violations of the 18-electron rule

Learn various synthetic techniques in organometallic chemistry

Implementation Notes

I provide the paper and the questions to students to work on ahead of class independently.  Depending on time constraints, students can compare answers in the classroom, and then turn in their answered questions.  We then review as a class, getting as much participation as possible.  Some questions are in regard to more advanced spectroscopy techniques, so these typically do not get good answers and require more explanation.

Time Required
20 minutes in class
Evaluation Methods

I usually grade for completeness and effort.  The goal is to have students reading more primary literature.

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


Chip Nataro / Lafayette College

Really cool LO Wes. Looks like you do CBC a little different. The Cp2Co- should be treated as neutral equivalent class. That would make the ML4X2- into ML5X. That gives you 11 electrons from the ligands and 9 from Co to give you 20. Ultimately, like all of this, it is just a method of counting, so nothing critical.

Fri, 06/21/2024 - 11:44 Permalink