µ2-Oxo-Bis[(2,5-Dinitrophenoxo)triarylantimony]: Syntheses, Structures, and Reactions with Pentaarylantimony

Abstract

Antimony aroxides [Ph3SbOC6H3(NO2)2-2,5]2O (I) and [(4-MeC6H4)3SbOC6H3(NO2)2-2,5]2O (II) were synthesized by the oxidation of triarylantimony with tert-butyl hydroperoxide in the presence of 2,5-dinitrophenol. The SbOSb fragments in compounds I and II are bent (the corresponding angles are 139.70(10)° and 142.32(12)°). The Sb−Оbr bonds (1.973(3), 1.980(3) A in I; 1.975(2), 1.977(2) A in II) are substantially shorter than Sb−Ot (2.211(3), 2.213(3) and 2.191(2), 2.191(2) A in I and II, respectively). Aroxides Ar4SbOC6H3(NO2)2-2,5 (Ar = Ph (III) and 4-MeC6H4 (IV)) and carbonates (Ar4Sb)2CO3 (Ar = Ph (V) and 4-MeC6H4 (VI)) are formed from Ar5Sb and compounds I and II in the presence of oxygen and carbon dioxide, respectively. In the trigonal bipyramidal molecules of compounds III and IV, the СSbO axial angles are 175.80(7)° and 176.86(10)° (Sb−O 2.290(2) and 2.342(2) A, respectively). One of the antimony atoms in compound V and in crystallographically independent molecules of two types of compound VI is pentacoordinated (the Sb−Oax bond is 2.245(6) A in V and is 2.263(3) and 2.263(3) A in VIа and VIb, respectively), whereas the second antimony atom is hexacoordinated (Sb−O 2.249(6) and 2.273(5) A in V; 2.216(2), 2.251(2) A and 2.217(2), 2.251(2) A in VIа and VIb). The crystallographic data are deposited with the Cambridge Crystallographic Data Centre (СIF files ССDС nos. 1890704 (I), 1890706 (II), 1890713 (III), 1890714 (IV), 994519 (V), and 994177 (VI)).