How Frustrated Lewis Acid/Base Systems Pass through Transition‐State Regions: H2 Cleavage by [tBu3P/B(C6F5)3]. Issue 14 (8th August 2014)

• Record Type: Journal Article
• Authors: Pu, Maoping; Privalov, Timofei
• Is Part Of: Chemphyschem. Volume 15:Issue 14(2014)
• Page Start: 2936
• Page End: 2944
• Publication Date: 2014-08-08
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201402450
• Languages: English
• ISSNs: 1439-4235

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>We investigate the transition‐state (TS) region of the potential energy surface (PES) of the reaction <italic>t</italic>Bu₃P+H₂+B(C₆F₅)₃→<italic>t</italic>Bu₃P‐H⁽⁺⁾+⁽⁻⁾HB(C₆F₅)₃ and the dynamics of the TS passage at room temperature. Owing to the conformational inertia of the phosphane⋅⋅⋅borane pocket involving heavy <italic>t</italic>Bu₃P and B(C₆F₅)₃ species and features of the PES <italic>E</italic>(P⋅⋅⋅H, B⋅⋅⋅H | B⋅⋅⋅P) as a function of P⋅⋅⋅H, B⋅⋅⋅H, and B⋅⋅⋅P distances, a typical reactive scenario for this reaction is a trajectory that is trapped in the TS region for a period of time (about 350 fs on average across all calculated trajectories) in a quasi‐bound state (scattering resonance). The relationship between the timescale of the TS passage and the effective conformational inertia of the phosphane⋅⋅⋅borane pocket leads to a prediction that isotopically heavier Lewis base/Lewis acid pairs and normal counterparts could give measurably different reaction rates. Herein, the predicted quasi‐bound state could be verified in molecular collision experiments involving femtosecond spectroscopy.</p> </abstract>