Experiments and Direct Dynamics Simulations That Probe η²-Arene/Aryl Hydride Equilibria of Tungsten Benzene Complexes.

ABSTRACT: Key steps in the functionalization of an unactivated arene often involve its dihaptocoordination by a transition metal followed by insertion into the C-H bond. However, rarely are the η²-arene and aryl hydride species in measurable equilibrium. In this study, the benzene/phenyl hydride equilibrium is explored for the {WTp(NO)(PBu₃)} (Bu = n-butyl; Tp = trispyrazoylborate) system as a function of temperature, solvent, ancillary ligand, and arene substituent. Both face-flip and ring-walk isomerizations are identified through spin-saturation exchange measurements, which both appear to operate through scission of a C-H bond. The effect of either an electron-donating or electron-withdrawing substituent is to increase the stability of both arene and aryl hydride isom

SUBMITTER: Smith JA 

PROVIDER: S-EPMC7778736 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature