Tri-para-Tolylantimony Dicarboxylates (4-MeC6H4)3Sb[OC(O)R)]2, R = C6H4(NO2-3), C6H3(NO2)2-3,5, CH2Br: Synthesis and Structure

Abstract

Tri-para-tolylantimony bis(3-nitrobenzoate) (I), tri-para-tolylantimony bis(3,5-dinitrobenzoate) (II), and tri-para-tolylantimony bis(bromoacetate) (III), in which the Sb atoms have a trigonal bipyramidal coordination according to X-ray diffraction analysis, have been synthesized by the reaction of tri-para-tolylantimony (4-MeC₆H₄)₃Sb with 3-nitrobenzoic, 3,5-dinitrobenzoic, and bromoacetic acids in the presence of tert-butyl hydroperoxide. The OSbO axial angles are 171.83(12)°, 173.06(9)°, and 173.82(10)°. The Sb-O and Sb-C bond lengths are 2.109(3), 2.123(3), and 2.095(4)–2.111(5) Å in I, 2.108(2), 2.133(3), and 2.095(4)–2.103(3) Å in II, 2.126(3), 2.133(3), and 2.102(3)–2.115(3) Å in III. The Sb⋯O intramolecular distances (3.105(5), 3.168(5) in I, 3.060(4), 3.096(4) in II, 3.069(4), 3.100(4) ⋯ in III) are ∼0.5 ⋯ smaller than the sum of the antimony and oxygen van der Waals radii.