Synthesis and Structure of 2,5-Bis[N‑(2,6-mesityl)iminomethyl]pyrrolylcobalt(II): Evidence for One-Electron-Oxidized, Redox Noninnocent Ligand Behavior

The title complex Co­(Mes₂pyr)­Cl₂ is prepared from CoCl₂ and (Mes₂pyr)­H. Instead of the expected (Mes₂pyr)­CoCl complex, a complex with formula (Mes₂pyr)­CoCl₂ is isolated wherein the angle strain of the Mes₂pyr ligand results in metal ligation by only two of the three ligand donor atoms. Careful examination of structural, spectroscopic, and magnetic features indicates this compound is best described as a complex of high-spin Co­(II) with a neutral radical ligand.