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Yu-RedElim.pdf (1.05 MB)

Force-Modulated Reductive Elimination from Platinum(II) Diaryl Complexes

preprint
submitted on 18.09.2020, 19:20 and posted on 21.09.2020, 10:12 by Yichen Yu, Liqi Wang, Chenxu Wang, Yancong Tian, Roman Boulatov, Ross Widenhoefer, Stephen Craig

Coupled mechanical forces are known to drive a range of covalent chemical reactions, but the interplay of mechanical force applied to a spectator ligand and transition metal reactivity is relatively unexplored. Here we report the effect of mechanical force on the rate of C(sp2)-C(sp2) reductive elimination from platinum(II) diaryl complexes containing macrocyclic bis(phosphine) force probe ligands. Compressive forces decreased the rate of reductive elimination whereas extension forces increased the rate of reductive elimination relative to the strain-free MeOBiphep complex with a 3.4-fold change in rate over a ~290 pN range of restoring forces. The natural bite angle of the free ligand changes with force, but 31P NMR analysis strongly suggests no significant force-induced perturbation of the ground state geometry of the (P–P)PtAr2 complexes. Rather, the force/rate behavior observed across this range of forces (from ca. 65 pN in compression to >200 pN in extension) for reductive elimination is attributed to the coupling of force to the elongation of the OO distance in the transition state for reductive elimination. The results suggest opportunities to experimentally map geometry changes associated with reactions in transition metal complexes and potential strat-egies for force-modulated catalysis.


Funding

Multi-State Catalysts Modulated by Mechanical Force

Basic Energy Sciences

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ACI-1548562

TG-CHE140039

58885-ND7

Chemomechanics: a bridge across the formidable gap

Engineering and Physical Sciences Research Council

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History

Email Address of Submitting Author

stephen.craig@duke.edu

Institution

Duke University

Country

USA

ORCID For Submitting Author

0000-0002-8810-0369

Declaration of Conflict of Interest

No conflict of interest

Version Notes

submitted v1 sept2020

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