Tetra(Para-Tolyl)Antimony Ferrocene Carboxylate: Synthesis and Structure

Abstract

The reaction of penta(para-tolyl)antimony with ferrocene carboxylic acid in benzene (heat-ing at 80 °C for 15 minutes) leads to the formation of tetra(para-tolyl)antimony ferrocene car-boxylate (4-MeC6H4)4SbOC(O)C5H4FeC5H5 (1). Complex 1 has been characterized by IR spec-troscopy, and its structure has been established by X-ray diffraction analysis. The IR spectrum of 1, recorded on a Shimadzu IRAffinity-1S FTIR spectrometer in KBr matrix contains bands characterizing the vibrations of the Sb–C, Sb–O bonds, the CO2-group, and the ferrocene frag-ment in the range of 4000–400 cm–1. The X-ray structural analysis of the complex was carried out on an automatic four-circle D8 Quest Bruker diffractometer (МоКα-radiation, λ = 0.71073 Å, graphite monochromator) at 293 K. Crystallographic characteristics of 1: triclinic syngony, space group P-1, a = 11.02(2), b = 13.00(2), c = 13.519(19) Å,  = 68.92(5), β = 81.26(7),  = 65.71(7) deg., V = 1648(5) Å3, Z = 2, calc = 1.442 g/cm3, 2 5.674.32 deg., total reflections 96987, independent reflections 16158, number of refined parameters 392, Rint = 0.0701, GOOF 1.060, R-factors for F2 > 2σ(F2) R1 = 0.0829, wR2 = 0.2390, R-factors for all reflections R1 = 0.1224, wR2 = 0.2597, residual electron density (max/min), 3.38/2.04 e/Å3. In the monomeric molecule of crystal 1 the coordination of the antimony atom is distorted octahedral, due to the fact that the carboxylate ligand is a bidentate chelating one. The diagonal angles in the octahedron are 147.5(2), 156.7(2), 167.0(2). The Sb–O(1) and Sb–O(2) distances are 2.475(6) and 2.313(5) Å, the Sb–C bonds differ significantly (2.114(6), 2.142(6), 2.152(6), 2.168(6) Å). The structural organization of the crystal is mainly due to the С–Н•••-type interactions.