Radical Complexes of Nickel(II)/Copper(II) and Redox Non-innocent MB-DIPY Ligands: Unusual Stability and Strong Near-Infrared Absorption at λ_max ∼1300 nm

MB-DIPY-based stable radicals with redox-switchable absorption beyond 1000 nm have been prepared and characterized by spectroscopic and theoretical methods. Stable radical complexes can be either oxidized to regular [M^II(MB-DIPY)]⁺ (M=Cu or Ni) or reduced to [M^II(MB-DIPY)]^- compounds within an ∼400 mV electrochemical window.