Mechanistic Insights into Molecular Oxygen Reactivity with Late Transition Metal–Hydride Bonds
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide A gold complex, [( t Bu PCP)Au–H] + ( t Bu PCP = 2,6-bis(di- tert -butylphosphinomethyl)benzene), has been recently reported to insert O 2 into the Au(III)–H bond, leading to a stable Au(III)–OOH complex with an observed kinetic behavior sharing similarities with those of previously reported Pd(II)–H (nonradical) and Pt(IV)–H (autoaccelerated radical chain) reactions with O 2 . In this work, we computationally investigate, by inclusion of spin–orbit coupling (SOC) effects, along the adiabatic PES, this elusive reaction mechanism in connection with the Au(III)–H bond nature and in comparison with recent case studies involving isostructural Pd(II)–H ([( t Bu PCP)Pd–H]) or different ligand supported Au(III)–H ([(CNC)Au–H], CNC = 2,6-bis(alkylimidazol-2-ylidene)-pyridine) bonds. The M–H (M = Au, Pd) bonds in these complexes are shown to be mainly of electron-sharing nature, featuring, however, a decreasing degree of M(δ+)–H(δ−) polarization in the order [( t Bu PCP)Pd–H] > [( t Bu PCP)Au–H] + > [(CNC)Au–H], which we propose to be related to their reactivity with dioxygen, with the M–H bond displaying no reactivity ([(CNC)Au–H]), a radical chain ([( t Bu PCP)Au–H] + ), and a nonradical ([( t Bu PCP)Pd–H]) reactivity. The decisive factors in dictating the M–H bond polarity and, consequently, the preferred pathway lie in the nature of both the ligand and the metal, demonstrating how the fine-tuning of the electronic structure of these complexes causes mechanistic pathways to diverge.
Source: Inorganic Chemistry
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4412372504