Three new o-thioetherphenol ligands have been synthesized: 1,2-bis(3,5-di-tert-butyl-2-hydroxyphenylsulfanyl)ethane (H 2 bse), 1,2-bis(3,5-di-tert-butyl-2-hydroxyphenylsulfanyl)benzene (H 2 bsb), and 4,6-di-tert-butyl-2-phenylsulfanylphenol (Hpsp). Their complexes with copper(II) were prepared and investigated by UV-Vis-, EPR-spectroscopy; their electro- and magnetochemistry have also been studied: [Cu I I (psp) 2 ] (1), [Cu I I 2 (bse) 2 ] (2), [Cu I I 2 (bsb) 2 ] (3), [Cu I I (bsb)(py) 2 ] (4). The crystal structures of the ligands H 2 bse, H 2 bsb, Hpsp and of the complexes 1, 2, 3, 4 have been determined by X-ray crystallography.