The Minor Product [Ph3Sb(Cl)O]3C•PhH in the Ligand Redistribution Reactions of Pentavalent Antimony Aryl Derivatives
Abstract
One of the reaction products of triphenylantimony dichloride and triphenylantimony bis(2,4-dibromophenoxide) (1:1 mol.) in benzene in air is the compound of three-coordinated carbon [Ph3Sb(Cl)O]3C × PhH (1). The compound has been identified by IR spectroscopy and X-ray diffraction analysis. According to the X-ray diffraction analysis the target product is a benzene solvate [С61H51Cl3O3Sb3, М = 1303.65; the monoclinic system, space group P21/c; a 17.17(2), b 18.75(2); c 17.322(18) Å; α 90.00, β 90.58(5), γ 90.00 град.; V 5576(11) Å3; Z 4; µ 1.630 mm–1; F(000) 2580.0; crystal size 0.28 × 0.22 × 0.11 mm; 2θ for data collection 6.4 - 36.8 degrees; index ranges −15 ≤ h ≤ 15, −16 ≤ k ≤ 16, −15 ≤ l ≤ 15; total reflections 24392; independent reflections 3981; Rint 0.0516; variables 632, GOOF 1.141; R1 = 0.0392; wR2 = 0.0912; residual electron density 0.43/–0.35 e/Å3]. The COSb angles in the compound 1 vary in the interval 123.3(8)-127.1(8)°. The C–O shortened distances (1.365(15)–1.385(15) Å) compared to the sum of the covalent radii of carbon and oxygen atoms (1.51 Å) indicate an increase in the multiplicity of these bonds. The abnormal reduction of Sb–O distances (1.986(7), 2.001(7), 2.011(7) Å) in the neutral molecule 1 compared to the sum of the covalent radii of antimony and oxygen atoms (2.14 Å) implies delocalization of the electron density in the CO3Sb3 core. The Sb – Cl distances are slightly longer than the sum of the covalent radii of antimony and chlorine atoms and are longer than ones in triphenylantimony dichloride. The antimony atoms have a distorted trigonal-bipyramidal coordination with heteroatoms in axial positions. The formation of the crystal structure is due to the formation of weak hydrogen bonds such as С···Н (2.72-2.90 Å) and Сl···Н (2.94 Å). Complete tables of coordinates of atoms, bond lengths and valence angles are deposited at the Cambridge Structural Data Bank (No. 1851485; deposit@ccdc.cam.ac.uk; http:// www.ccdc.cam.ac.uk/data_request/cif).
