Triphenylantimony(V) Catecholates Based on o-Quinones, Derivatives of Benzo[b][1,4]-Dioxines and Benzo[b][1,4]-Dioxepines

New catecholate complexes of triphenylantimony(V), (Etgly-3,6-DBCat)SbPh3 (I), (Propgly-3,6-DBCat)SbPh3 (II), and (Cat-3,6-DBCat)SbPh3 (III), based on analogs of sterically hindered 3,6-di-tert-butyl-o-benzoquinone, 5,8-di-tert-butyl-2,3-dihydrobenzo[b][1,4]dioxine-6,7-dione (L1), 6,9-di-tert-butyl-2,3-dihydrobenzo[b][1,4]dioxepine-7,8-dione (L2), and 1,4-di-tert-butyl-dibenzo[b,e][1,4]dioxine-2,3-dione (L3), which are the 2,3-dihydrobenzo[b][1,4]dioxine, 2,3-dihydrobenzo[b][1,4]dioxepine, and dibenzo[1,4]dioxine derivatives, respectively, have been synthesized. At room temperature catecholates I and II react with molecular oxygen adding an O2 molecule to form the corresponding spiroendoperoxides IV and V. Catecholate III reacts with oxygen with the deep oxidation of the complex and formation of neutral o-benzoquinone. The molecular structures of complexes I and III are determined by X-ray diffraction analysis (CIF files CCDC nos. 1840299 (I · toluene) and 1840300 (III)).