Tetra(para-tolyl)antimony ferrocene carboxylate: synthesis and structure. Synthesis and structure

The reaction of penta(para-tolyl)antimony with ferrocene carboxylic acid in benzene (heating at 80 °C for 15 minutes) leads to the formation of tetra(para-tolyl)antimony ferrocene carboxylate (4-MeC6H4)4SbOC(O)C5H4FeC5H5 (1). Complex 1 has been characterized by IR spectroscopy, 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 fragment 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, a = 68.92(5), β = 81.26(7), g = 65.71(7) deg., V = 1648(5) Å3, Z = 2, rcalc = 1.442 g/cm3, 2q 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···p-type interactions.