Origin of Intramolecular versus Intermolecular C–H Arene Activation Selectivity by Cyclopentadienyl–Triphenylphosphine Iridium DOI
Bowen Zhang, Daniel H. Ess, Michael B. Hall

et al.

Inorganic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: April 14, 2025

Photolysis of (η5-C5Me5)Ir(PPh3)(H)2 in benzene generates the 16-electron (16e-) complex (η5-C5Me5)Ir(PPh3) that undergoes competitive intramolecular ortho-metalation with a phenyl group from -PPh3 and intermolecular C-H activation benzene. Previous density functional theory (DFT) studies identified π-complex intermediates their corresponding transition states. However, neither mechanism interconversion between these nor origin versus pathway selectivity has been established. Here, we characterized open-shell 16e- iridium species extensively mapped out energy landscape for activation. Also, performed DFT-based direct dynamics simulations, results suggest is determined dynamically within picoseconds as evolves into coordinatively saturated structure. During this process, π-complexes are formed concurrently with, instead prior to, hydrides, which could not be explained by kinetic models assume cleavage rate-limiting step. These findings demonstrate simulations addition to DFT calculations needed more complete mechanistic understanding photoinduced reactions, product can influenced atomic motion.

Language: Английский

Origin of Intramolecular versus Intermolecular C–H Arene Activation Selectivity by Cyclopentadienyl–Triphenylphosphine Iridium DOI
Bowen Zhang, Daniel H. Ess, Michael B. Hall

et al.

Inorganic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: April 14, 2025

Photolysis of (η5-C5Me5)Ir(PPh3)(H)2 in benzene generates the 16-electron (16e-) complex (η5-C5Me5)Ir(PPh3) that undergoes competitive intramolecular ortho-metalation with a phenyl group from -PPh3 and intermolecular C-H activation benzene. Previous density functional theory (DFT) studies identified π-complex intermediates their corresponding transition states. However, neither mechanism interconversion between these nor origin versus pathway selectivity has been established. Here, we characterized open-shell 16e- iridium species extensively mapped out energy landscape for activation. Also, performed DFT-based direct dynamics simulations, results suggest is determined dynamically within picoseconds as evolves into coordinatively saturated structure. During this process, π-complexes are formed concurrently with, instead prior to, hydrides, which could not be explained by kinetic models assume cleavage rate-limiting step. These findings demonstrate simulations addition to DFT calculations needed more complete mechanistic understanding photoinduced reactions, product can influenced atomic motion.

Language: Английский

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