Thermodynamic and Structural Factors That Influence the Redox Potentials of Tungsten–Alkylidyne Complexes
The thermodynamic and structural factors that influence the redox properties of an extensive set of tungsten–alkylidyne complexes (W(CR)L4X) are analyzed by combining synthesis, electrochemistry, and computational modeling based on free energy calculations of oxidation potentials at the density functional theory level. The observed linear correlations among oxidation potentials, HOMO energies, and gas-phase ionization energies are found to be consistent with the approximately constant solvation free energy differences between reduced and oxidized species over the complete set. The W–X bond length, trans to the alkylidyne ligand, is found to be a good descriptor of the positioning of the key frontier orbitals that regulate the redox properties of the complexes.