Transition metal complexes that can mediate the cleavage of otherwise strong bonds are highly sought after for the purposes of use in synthetic processes. C-H bond functionalization is an important transformation in organic chemistry as it can permit the conversion of cheap and abundant molecules like alkanes into value-added compounds, such as converting methane into methanol. Prior research in this field has shown limited success with the use of platinum complexes, but the need for a stoichiometric platinum oxidant has prevented the work from developing into a practical process. Thus, there is a need for more active and less expensive catalysts for C-H activation. Work in the O’Connor lab is focused on the synthesis of new electrophilic iridium complexes that are capable of catalytically activating strong C-H bonds, which could then be functionalized. By exploiting the stabilizing effects of chelating, electronically rich ligand scaffolds we hope to attain and stabilize the higher oxidation states on iridium, in particular the Ir(III)-Ir(V) couple. We report here the synthesis and characterization of new [N,N,N]-dianionic pincer ligands and iridium complexes containing these new ligands. Preliminary results highlighting catalytic H/D exchange reactions with benzene are also described. Efficiency of the catalysts has been analyzed in terms of turn-over number and frequency with the end goal of developing more active and selective catalysts for this C-H activation.

Progress toward the synthesis, characterization, and catalysis of iridium complexes containing [N,N,N]-dianionic pincer ligands

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.