Triarylantimony(V) catecholates - Derivatives of 4,5-difluoro-3,6-di-tert-butyl-o-benzoquinone

Novel triarylantimony(V) 4,5-difluoro-3,6-di-tert-butylcatecholates have been synthesized. Their electrochemical oxidation proceeds as two consecutive stages with formation of stable mono- and unstable dicationic derivatives. The fluorine substituents in Cat ligand behave as weak donors with positive mesomeric effect: the first oxidation potential “Cat/SQ” is only insufficiently shifted to the anodic region, while the second oxidation step “SQ/Q” is facilitated. Complexes (4,5-F2-3,6-Cat)SbPh3 and (4-Cl-3,6-Cat)SbPh3 form an unusual hexamolecular core [CatSbPh3]6 in crystals.