The Mechanism of CO sub(2) Insertion into Iridium(I) Hydroxide and Alkoxide Bonds: A Kinetics and Computational Study

• Published in: Chemistry : a European journal 2015-04, Vol.21 (18), p.6930-6935
• Main Authors: Truscott, Byron J, Kruger, Hedi, Webb, Paul B, Buehl, Michael, Nolan, Steven P
• Format: Article
• Language: English
• Subjects: Alkoxides; Amides; Carbon capture and storage; Carbon dioxide; Correlation; Hydroxides; Insertion; Reaction kinetics
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201406509

The facile insertion of CO sub(2) into iridium(I) hydroxide, alkoxide, and amide bonds was recently reported. In particular, [Ir(cod)(IiPr)(OH)] (IiPr=1,3-bis(isopropyl)imidazol-2-ylidene) reacted with CO sub(2) in solution and in the solid state in a matter of minutes to give the novel [{Ir(cod)(IiPr)} sub(2)( mu - Kappa super(1)O: Kappa super(2)O,O-CO sub(3))] complex. In the present study, this reaction is probed using kinetics and theoretical studies, which enabled us to analyse its facile nature and to fully elucidate the reaction mechanism with excellent correlation between the two methods. The insertion of CO sub(2) into iridium(I) hydroxide and alkoxide bonds is examined from both a kinetics and thermodynamic perspective. The two methods showed excellent correlation, shedding much needed light on the mechanism of CO sub(2) fixation by Ir super(I) complexes.