12 research outputs found
CâH Bond Activation by Iridium(III) and Iridium(IV) Oxo Complexes
Oxidation of an iridium(III) oxo precursor enabled the structural, spectroscopic, and quantum-chemical characterization of the first well-defined iridium(IV) oxo complex. Side-by-side examination of the proton-coupled electron transfer thermochemistry revealed similar driving forces for the isostructural oxo complexes in two redox states due to compensating contributions from H+ and eâ transfer. However, CâH activation of dihydroanthracene revealed significant hydrogen tunneling for the distinctly more basic iridium(III) oxo complex. Our findings complement the growing body of data that relate tunneling to ground state properties as predictors for the selectivity of CâH bond activation.</p
Interconversion of Phosphinyl Radical and Phosphinidene Complexes by Proton Coupled Electron Transfer
The isolable complex [Os(PHMes*)H(PNP)] (Mes*=2,4,6âtBu3C6H3; PNP=N{CHCHPtBu2}2) exhibits high phosphinyl radical character. This compound offers access to the phosphinidene complex [Os(PMes*)H(PNP)] by PâH proton coupled electron transfer (PCET). The PâH bond dissociation energy (BDE) was determined by isothermal titration calorimetry and supporting DFT computations. The phosphinidene product exhibits electrophilic reactivity as demonstrated by intramolecular CâH activation
Interconversion of Phosphinyl Radical and Phosphinidene Complexes by Proton Coupled Electron Transfer
The isolable complex [Os(PHMes*)H(PNP)] (Mes*=2,4,6âtBu3C6H3; PNP=N{CHCHPtBu2}2) exhibits high phosphinyl radical character. This compound offers access to the phosphinidene complex [Os(PMes*)H(PNP)] by PâH proton coupled electron transfer (PCET). The PâH bond dissociation energy (BDE) was determined by isothermal titration calorimetry and supporting DFT computations. The phosphinidene product exhibits electrophilic reactivity as demonstrated by intramolecular CâH activation