Synthesis and structure investigation of organic compounds of antimony (V) with unsaturated carbonic acids Ph3Sb[OC(O)R]2

Triphenylantimony dicarboxylates Ph3Sb[OC(O)CH=CH2]2, Ph3Sb[OC(O)C(CH3)=CH2]2, Ph3Sb[OC(O)CH=CHCH3]2, Ph3Sb[OC(O)CH=CHC4H3O]2, Ph3Sb[OC(O)CH=CHPh]2, Ph3Sb[OC(O)CH=CHC6H4NO2- m ]2, Ph3Sb[OC(O)CH=CHC6H4OMe- p ]2, Ph3Sb[OC(O)CH=CHCH=CHCH3]2 were obtained with the reaction of triphenylantimony and carboxylic acids in the presence of hydrogen peroxides in ether or THF. Triphenylantimony dicarboxylate yields were 59-86 %. The structure of the obtained products was confirmed by elemental analysis, IR, 1H-NMR spectroscopy. According to the X-ray diffraction data, the antimony atom can be in a trigonal-bipyramidal, tetragonal-pyramidal, and “intermediate” configuration. In all compounds additional coordination of the antimony atom with carbonyl oxygen atoms is observed, and this effect is most pronounced in triphenylantimony m -nitrocinnamate. In the case of a distorted trigonal-bipyramidal configuration, the two angles in the equatorial plane vary within 104,03(4)-112,59(9), the third angle significantly exceeds these values 135,43(9)-149,81(8). This fact is associated with the location of carbonyl oxygen atoms O2 and O4 between the phenyl substituents. The sum of the angles in the equatorial plane is 360º. Ranges of the Sb-O and Sb-C bond lengths are 2,104(2)-2,163(7) Å and 2,103(16)-2,128(1) Å. The O1-Sb-O3 bond angles are 172,18 (6)-78,00 (4)º. The intramolecular Sb…O2 and Sb…O4 distances are equal to 2,583-3,060 Å. The carboxylate residue of unsaturated carboxylic acids has a flat structure, all valent angles are close to 120º, which confirms the participation of all carbon and oxygen atoms in the formation of the single conjugate C=C-C(O)OSb system. In this case multiple bonds are shortened, while single bonds are elongated compared to those in acids. Intermolecular interactions in triphenylantimony acrylate, methacrylate, crotonate, and sorbate with the C=C double bonds of unsaturated carboxylate fragments of neighboring molecules have been revealed. In some compounds there is a co-crystallized solvent, which is included in the molecular packing.