Synthesis, Characterization, and Reversible Multielectron Redox Properties of a Biradical Yttrium Complex Containing Bis(2‐isopropylaminophenyl)amide

The redox‐active ligand bis(2‐isopropylaminophenyl)amide (NNN) was used to prepare ionic yttrium complex [(NNN sq · ) 2 Y] – [Li(thf) 4 ] + ( 2 ; sq = semiquinonate form). A solid‐state magnetic measurement on 2 ( µ eff = 2.40 µ B ) indicated the presence of two unpaired electrons on two separate NNN ligands. The paramagnetic compound 2 was characterized by EPR spectroscopy in a dilute frozen solution of thf, which suggested there was no intramolecular radical–radical interaction. Electrochemistry of 2 featured a quasireversible two‐electron reduction process at –1.193 V attributed to the 2 2– / 2 redox couple, and two successive one‐electron oxidation processes at –0.406 V and –0.156 V attributed to the reversible 2 / 2 + redox couple and quasireversible 2 + / 2 2+ redox couple, respectively.