The O'Hare group has studied complexes of the permethylpentalene ligand, and recently reported the reaction of a zirconium complex of this ligand with CO₂ to form the carbamate. A series of three different complexes were prepared, each with slightly different products upon reaction with CO₂, illustrating subtle differences in reactivity based on either sterics or electronics. To further tangle the web, entropic and enthalpic considerations can also be considered. 

Various topics ranging from coordination chemistry, electrochemistry, solid state chemistry and point group and symmetry are discussed from the JACS article published by Smaranda C. Marinescu and her co-workers.  The article describes the conversion of CO₂ to CO by using cobalt aminopyridine macrocycle catalysts.

The discussion covers a 2021 publication by the Chirik group (Nature Chemistry, 2021, DOI: 10.1038/s41557-020-00614-w) which details the discovery of a new way to polymerize butadiene through iron-catalyzed [2+2] cycloadd