This literature discussion is based on a 2022 Science paper describing a series of dilanthanide complexes with exceptional magnetic properties due to the presence of metal-metal bonding. These molecules are the first reported species to feature direct bonding between two lanthanides! The paper contains ample material for discussion of molecular symmetry and bonding, oxidation states and electron configurations, and magnetism. The handout includes a description, glossary, discussion questions, and pre-class worksheet.
A student should be able to...
- Assign oxidation states to metal ions in organometallic complexes
- Write a ground-state electron configuration for a metal atom or ion
- Sketch and populate a simple MO diagram featuring metal-metal bonding
- Define Hund's Rule and explain its significance to the magnetic behavior of molecules
- Describe techniques used in the research paper to provide evidence of metal-metal bonding and magnetic properties
I constructed this literature discussion on the basis of a related homework question that I wrote for my upper-level Inorganic Chemistry course. The homework problem was unwieldy and did not quite get students to understand the complexities of this research or appreciate how amazing these molecules are! In the future, I plan to dedicate a full class to this literature discussion to give it the attention it deserves!
The discussion is designed to be used toward the end of the semester to tie multiple previous topics together and introduce ideas about magnetism. The assignment assumes that students have been introduced to the concepts of Hund's Rule and electron configurations, symmetry and group theory, and assigning oxidation states in complexes. The questions about the point group and MO symmetry could be removed if this topic has not been covered. My course's coverage of magnetic behavior is rather limited, so the questions about magnetic moment, magnetic susceptibility, and coercivity could be expanded upon if this topic is more focused on.
I have not yet implemented this literature discussion in my class. In the future, I plan to dedicate a class day to the discussion questions, after assigning the worksheet as a pre-class exercise to be completed for participation credit.
As a homework problem set, this exercise was too unwieldy and did not land for my students. Expanding it to a full-class activity and discussion will give it the attention it deserves!