Enhanced Dihydrogen Activation by Mononuclear Iridium(II) Compounds: A Mechanistic Study

• Published in: Angewandte Chemie Vol. 134; no. 35
• Main Authors: Hidalgo, Nereida, Moreno, Juan José, García‐Rubio, Inés, Campos, Jesús
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 26-08-2022
• Subjects: Chemistry; Computer applications; Dihydrogen; Heavy metals; Iridium; Iridium compounds; Metalloradical; Organometallic compounds; Paramagnetic Compounds; Transition metals
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202206831

The organometallic chemistry of 4d and 5d transition metals has been vastly dominated by closed‐shell states. The reactivity of their metalloradical species is though remarkable, albeit yet poorly understood and with limited mechanistic investigations available. In this work we report the synthesis and characterization of two mononuclear IrII species, including the first dinitrogen adduct. These compounds activate dihydrogen at a dissimilar rate, in the latter case several orders of magnitude faster than its IrI precursor. A combined experimental/computational investigation to ascertain the mechanism of this transformation in IrII compounds is reported.
Two exotic iridium(II) compounds, including the first IrII‐dinitrogen adduct are prepared. The IrII‐dinitrogen adduct activates dihydrogen far more rapidly than its IrI counterpart. A joint experimental/computational effort to elucidate the H2 cleavage mechanism is presented, which enhances the limited mechanistic understanding of reactions mediated by heavier transition‐metal paramagnets.