Students are asked to find a coordination complex in the recent literature and analyze its structure. This homework or in-class activity is a great way for the instructor to crowd source the discovery of interesting new complexes to use as material in future exams.
After completing this activity, students should be able to:
- browse the inorganic literature
- draw coordination complexes
- identify a complex’s coordination number
- identify the oxidation state of a metal and count its d electrons
I have assigned this problem as a take-home problem after my first lecture about coordination complexes. However, it could potentially be used as an in-class activity instead.
I compile the students’ complexes into a review document that I give them for extra practice before the exam on coordination complexes. I take images of the structures directly from the journal articles rather than draw them myself, but an instructor could just as easily ask the students to re-draw the structures using Chem Draw as part of the assignment. Some of my students have had little practice using Chem Draw, especially for more complex molecules. After a few years of assigning this problem, I now have a large repository of complexes to draw from in writing exam questions.
I review nomenclature rules in my advanced inorganic class, but I don’t put a lot of emphasis on requiring students to be able to name complexes. They do seem to enjoy making the connection between a long and complicated name and the complex’s structure.
Some students run into trouble accessing the journal from off-campus computers; our campus library does provide a way to do this, but many students need a reminder about how to log in and get permission.
This assignment takes the “ionic” approach to electron counting in coordination complexes, but it could be adapted to ask students to use the “covalent” approach instead.
I have graded this problem on a “complete” vs “incomplete” basis as part of my daily homework system. (For a description of the system, see the forum discussion here: https://www.ionicviper.org/forum-topic/creative-solutions-homework ) It turns out that many of the solutions to the problem (ie, metal oxidation state) can often be found in the journal article. This doesn’t bother me too much because my main goals for the problem are to give students the experience of browsing an online journal and to gather complexes for use in future problems.
Most students do well on this assignment. I think student performance mostly depends on the amount of time I’ve given the topic in lecture before the problem is assigned.