Independent Tuning of the p or the in a Family of Ruthenium Pyridine-Imidazole Complexes.

Two series of Ru(acac)(py-imH) complexes have been prepared, one with changes to the acac ligands and the other with substitutions to the imidazole. The proton-coupled electron transfer (PCET) thermochemistry of the complexes has been studied in acetonitrile, revealing that the acac substitutions almost exclusively affect the redox potentials of the complex (|Δ| ≫ |Δp|·0.059 V) while the changes to the imidazole primarily affect its acidity (|Δp|·0.