Solvent dependent C−H Bond Strength in a Nickel Pincer Complex

Metal coordination can substantially weaken the bond strength of X−H bonds in coordinated ligands. Despite the importance for redox catalysis, this phenomenon is surprisingly scarcely examined for C−H bonds of organometallic compounds. We here report a nickel(I) pincer complex with a remote methylene group in the ligand backbone that exhibits an unusually solvent dependent C−H bond dissociation free energy (BDFEC−H). Structural and thermochemical characterization in MeCN and THF indicates that the BDFEC−H strongly depends on solvent binding to the metal within the NiII/NiI redox couple.