Synthesis and structure of bis(2,3,4,5-tetrafluorobenzoyloxy)triphenylantimony and tetraphenylantimony 2,3,4,5-tetrafluorobenzoate

Abstract

Bis(2,3,4,5-tetrafluorobenzoyloxy)triphenylantimony Ph3Sb[OC(O)C6HF4-2,3,4,5]2 (3) has been synthesized in 91 % yield by the reaction of triphenylantimony (1) with 2,3,4,5-tetrafluorobenzoic acid (2) and tert-butyl hydroperoxide (in the mole ratio of 1:2:1) in diethyl ether. Tetraphenylantimony 2,3,4,5-tetrafluorobenzoate Ph4SbOC(O)C6HF4-2,3,4,5 (5) has been obtained by the interaction between pentaphenylantimony (4) and compound 3 in benzene (95 % yield), as well as by the reaction of pentaphenylantimony 4 with 2,3,4,5-tetrafluorobenzoic acid 2 (86 % yield). According to the X-ray diffraction data, in compounds 3, 5 the antimony atoms have a trigonal bipyramidal coordination with the oxygen (3) or carbon and oxygen (5) atoms in axial positions. The sum of the equatorial CSbC angles in 3 and 5 is equal to 359.98(11)° and 356.52(6)°, respectively. The average value of the equatorial SbC bonds in 3 (2.104(3) Å) is less than in 5 (2.1132(16) Å). The SbO bond lengths in 3 (2.117 (2), 2.134 (2) Å) are significantly shorter than in 5 (2.2998 (13) Å). Molecular packing in crystals 3 and 5 is characterized by the presence of intermolecular contacts Sb⋯OC: 3.110(3), 2.982(2) Å, and 3.233(2) Å, respectively.