Binuclear Triphenylantimony(V) Catecholate Based on Redox-Active Bis-o-Benzoquinone, a Bis-Catechol-Aldimine Derivative

Abstract

The oxidative addition of bis-o-benzoquinone Q–(CH=N–N=CH)–Q (L), in which two 3,5-ditert-butyl-o-benzoquinones are linked to each other in positions 6 via the CH=N–N=CH group, to triphenylstibine gave a new binuclear triphenylantimony(V) bis-catecholate complex, Ph₃Sb(Cat–(CH=N–N=CH)–Cat)SbPh₃ (I). Recrystallization of I from a methanol–trichloromethane mixture resulted in an additional coordination of a methanol molecule to each antimony atom to give the binuclear complex, (CH₃OH)Ph₃Sb(Cat–(CH=N–N=CH)–Cat)SbPh₃(CH₃OH) (I · 2CH₃OH), the crystals of which (I · 2CH₃OH) · 2CH₃OH · CHCl₃ (II) contain additionally two methanol solvate molecules, which fix the geometry of the nitrogen-containing bridging group, and a trichloromethane molecule. The molecular structure of compound II in the crystalline state was determined by X-ray diffraction (CIF file CCDC no. 1560840).