Unprecedented iminobenzosemiquinone and iminobenzoquinone coordinated mononuclear Cu(II) complex formation under air

摘要

Two non-innocent 2-anilino-4,6-di-tert-butylphenol units were connected through an -ortho bridging S atom and provided the ligand H4LS(AP/AP). The ligand reacted with CuCl2 center dot 2H(2)O in the presence of Et3N under air and generated a mononuclear Cu(II) complex (1, [(CuLCl)-Cl-S(IBQ/ISQ)](0)). A single crystal X-ray diffraction analysis confirmed that in the complex one of the two 2-anilido-4,6-di-tert-butylphenol arms was present in its one-electron oxidized iminobenzosemiquinone form, while the other was in its two-electron oxidized iminobenzoquinone form. The monoradical-containing Cu(II) complex was diamagnetic in nature owing to a strong antiferromagnetic coupling between the single electron containing d(x2-y2) magnetic orbital of Cu(II) and the radical-centered unpaired electron.