Redox-Active Tin(IV) Complexes Based on Sterically Hindered Catecholate Ligands

The oxidative addition of sterically hindered 3,6-dicyclohexyl-o-benzoquinone (L¹), 3,5-di-tert-octyl-o-benzoquinone (L²), 4-tert-octyl-o-benzoquinone (L³), and 3,5-bis(2-phenylpropyl)-o-benzoquinone (L⁴) to tin(II) chloride in THF affords the corresponding tin(IV) catecholate complexes with the general formula RCatSnCl₂·2THF, where Cat is the catecholate fragment; and R is 3,6-с-Hex (I), 3,5-tert-Oct (II), 4-tert-Oct (III), and 3,5-C(Me)₂Ph (IV), regardless of the molar ratio of the starting reactants. The molecular structures of substituted o-benzoquinone L⁴ and complexes I and III in the crystalline form are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2259370 (L⁴), 2259371 (I), and 2259372 (III)). The oxidation–reduction properties of synthesized compounds I–IV are studied by cyclic voltammetry.