The migratory insertion reaction is one of the "four" main reactions in organometallic chemistry. It involves the formation of an acyl group by insertion of a CO molecule into a metal alkyl bond. The reaction is sometimes called the carbonyl insertion reaction because the product appears to be a result of direct insertion of the CO into the metal alkyl, but that name implies a mechanistic pathway that may not be in operation.
The reaction of methyl pentacarbonyl manganese(I), MeMn(CO)5, was studied extensively by Calderazzo in the mid 1960s. The use of C13 labeled CO and IR spectroscopy allowed for the identification of the mechanism for the reaction among the likely possibilities of direct insertion, alkyl migration, or carbonyl migration. This guided inquiry exercise presents some of the data from the Calderazzo paper and has students interpret it to determine the mechanism of the reaction in this system.
It should be noted that there are examples of all three mechanisms operating in different chemical systems, so this exercise is specific to the manganese substrate, though it is usually more generally applied.
Students will interpret and analyze IR data of metal carbonyls
Students will calculate IR bands for 13C labeled peaks in the IR
Students will predict product distributions for the three likely mechanisms (direct insertion, carbonyl migration, alkyl migration).
Students will compare expected and observed product distributions and identify the mechanism operating
Students will discover and discuss the concept of "negative evidence."
In my course, we usually cover isotopic labeling and its application to IR spectroscopy. We also use group theoretical methods to predict and assign M-CO stretches the correct symmetry labels and whether they are IR active or not. These two factors could be removed from the guided inquiry and presented as additional data to the students if you don't cover these topics. The rest of the activity is self contained. Access to the paper is not required, as the IR bands are in the document but a reference is provided.