Binuclear Triphenylantimony(V) Catecholates through N-Donor Linkers: Structural Features and Redox Properties.

A series of binuclear triphenylantimony(V) bis-catecholato complexes - of the type (Cat)PhSb-linker-SbPh(Cat) was prepared by a reaction of the corresponding mononuclear catecholates (Cat)SbPh with a neutral bidentate donor linker ligands pyrazine (Pyr), 4,4'-dipyridyl (Bipy), bis-(pyridine-4-yl)-disulfide (PySSPy), and diazobicyclo[2,2,2]octane (DABCO) in a dry toluene: Cat = 3,6-di-tert-butyl-catecholate (3,6-DBCat), linker = Pyr (); PySSPy (); Bipy (); DABCO (); Cat = 3,5-di-tert-butyl-catecholate (3,5-DBCat), linker = Bipy (); DABCO (); Cat = 4,5-(piperazine-1,4-diyl)-3,6-di-tert-butylcatecholate (pip-3,6-DBCat), linker = Bipy (); DABCO (); Cat = 4,5-dichloro-3,6-di-tert-butylcatecholate (4,5-Cl-3,6-DBCat), linker = Bipy (); DABCO (); and Cat = 4,5-dimethoxy-3,6-di-tert-butylcatecholate (4,5-(MeO)-3,6-DBCat), linker = Bipy (). The same reaction of (4,5-Cl-3,6-DBCat)SbPh with DABCO in an open atmosphere results in a formation of 1D coordination polymer {[(4,5-Cl-3,6-DBCat)SbPh·HO]·DABCO} (). Bis-catecholate complex PhSb(Cat-Spiro-Cat)SbPh reacts with Bipy as 1:1 yielding a rare macrocyclic tetranuclear compound {PhSb(Cat-Spiro-Cat)SbPh∙(Bipy)} ().