Distal scaffold flexibility accelerates ligand substitution kinetics in manganese(I) tricarbonyls: flexible thianthrene rigid anthracene scaffolds.

This work investigates the effect of molecular flexibility on fundamental ligand substitution kinetics in a pair of manganese(I) carbonyls supported by scaffold-based ligands. In previous work, we reported that the planar and rigid, anthracene-based scaffold with two pyridine 'arms' (, 2) serves as a bidentate, donor set, akin to a strained bipyridine (bpy). In the present work, we have installed a more flexible and dynamic scaffold in the form of thianthrene (, 1), wherein the scaffold in the free ligand exhibits a ∼130° dihedral angle in the solid state.