This assignment is intended as an introduction to searching the chemical literature to identify an article on specific topic (in this case a specific metal within a specified time range). Once they have located their articles, they are expected to name a metal complex and give the oxidation state, d electron count, and geometry.
After completing the assignment, the student should be able to
- Search an American Chemical Society journal for an article on a specific topic
- Use chemical nomenclature rules to name complexes found in the literature
Each student is assigned a column from the periodic table (such as columns 4-11) for this assignment. I assign this as we are talking about inorganic nomenclature, oxidation states, and d electron counts. We typically have not yet talked about more complex ligands and binding modes and how this affects geometry, so the geometry assignment is intended as a proposed geometry that they usually base off of structures in the articles. You may want to suggest that they look for articles that contain a stuctural image of the complex to aid in their geometry assignment. They are given a week to complete this assignment.
For some students, this is the first time that they have used the chemical literature, so I also provide a walk-through for finding ACS journal articles through our library website and through SciFinder. I have included these walk-throughs, but they will obviously need to be modified for your institution.
I have a tablet PC that I use for grading, so I have students turn this assignment in electronically, which allows the links to the articles to be active (and makes it easier for me to check their work).
Submissions are graded for the following criteria:
- Articles are for the proper metals, within the specified time range, and are from different research groups
- Articles are properly cited according to the ACS Style Guide and include a link to the article
- Metal complexes are named properly according to the nomenclature rules; oxidation state and d electron count are correct; the proposed geometry is accurate
Students generally have no trouble locating appropriate articles and citing them correctly. Students have scored an average of 29/35 for the past two years that I have used this learning object. Points are generally lost for incorrect naming, incorrect oxidation states/d electron counts, or the assignment of geometries that are not consistent with the number of ligands bound. Since we have not discussed multi-hapto ligands, I correct their geometries with these types of ligands but do not take off points. I also do not take off points for d0/d10 complexes with the improper geometry because we have not yet discussed CFSE/LFSE.
The clever students search specifically for complexes they know they can name (i.e. - [Ni(Cl)4]2-), but I have no problem with this, as one of the objectives is to learn how to search the literature for a specific topic, which they clearly can do!