Issue 33, 2021

Force-modulated reductive elimination from platinum(ii) diaryl complexes


Coupled mechanical forces are known to drive a range of covalent chemical reactions, but the effect of mechanical force applied to a spectator ligand on transition metal reactivity is relatively unexplored. Here we quantify the rate of C(sp2)–C(sp2) reductive elimination from platinum(II) diaryl complexes containing macrocyclic bis(phosphine) ligands as a function of mechanical force applied to these ligands. DFT computations reveal complex dependence of mechanochemical kinetics on the structure of the force-transducing ligand. We validated experimentally the computational finding for the most sensitive of the ligand designs, based on MeOBiphep, by coupling it to a macrocyclic force probe ligand. Consistent with the computations, compressive forces decreased the rate of reductive elimination whereas extension forces increased the rate relative to the strain-free MeOBiphep complex with a 3.4-fold change in rate over a ∼290 pN range of restoring forces. The calculated natural bite angle of the free macrocyclic ligand changes with force, but 31P NMR analysis and calculations strongly suggest no significant force-induced perturbation of ground state geometry within the first coordination sphere of the (P–P)PtAr2 complexes. Rather, the force/rate behavior observed across this range of forces is attributed to the coupling of force to the elongation of the O⋯O 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 strategies for force-modulated catalysis.

Graphical abstract: Force-modulated reductive elimination from platinum(ii) diaryl complexes

Supplementary files

Article information

Article type
Edge Article
11 Jun 2021
19 Jul 2021
First published
26 Jul 2021
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2021,12, 11130-11137

Force-modulated reductive elimination from platinum(II) diaryl complexes

Y. Yu, C. Wang, L. Wang, C. Sun, R. Boulatov, R. A. Widenhoefer and S. L. Craig, Chem. Sci., 2021, 12, 11130 DOI: 10.1039/D1SC03182A

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