This is a really interesting paper in J. Am. Chem. Soc. (2025, 147, 34641-34646) involving a complex salt in which both the cation and anion are metallocenes. While a majority of the paper is focused on the characterization of two new compounds, it presents some excellent opportunities to practice counting electrons, one of which was a challenge to this author.

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.

This literature discussion was inspired by a talk given by Dr. Nora Radu, recipient of the 2025 ACS Award for Distinguished Service in the Advancement of Inorganic Chemistry. It is a bit 'big picture' in nature in that the hydrocyanation reaction is important for the synthesis of nylon. As such, there is a significant amount of background material relating to nylon-6,6. Students will read an article from C&EN, portions of a patent, and portions of an article from J. Chem.

This Literature Discussion considers the synthesis of the first carbene-bismuthinidene complex by Gilliard and coworkers in 2019. This molecule serves as an illustration of different bonding models, as it can be described by multiple resonance structures invoking fully covalent, zwitterionic, and coordinate/dative bonding forms. Students analyze these resonance structures and their geometrical implications, then compare to the experimental structural evidence to come to a conclusion about which bonding model(s) best describe this molecule!