Synthesis and structure of tetra- and triphenylantimony phenylpropiolates

Tetraphenylantimony phenylpropiolate ( I ) has been synthesized by the reaction between pentaphenylantimony and phenylpropiolic acid or triphenylantimony bis(phenylpropiolate) in toluene. Triphenylantimony bis(phenylpropiolate) ( II ) has been synthesized from triphenylantimony and phenylpropiolic acid in ether in the presence of tert -butylhydroperoxide. According to X-ray diffraction data, the antimony atoms in complexes I and II are in a trigonal bipyramidal coordination, and the axial CSbO and OSbO angles are 178.63(7)° and 177.68(7)°. The Sb-C and Sb-O bond lengths and the equatorial CSbC angles are 2.120(3)–2.166(3) and 2.267(2) Å, and 113.44°, 114.80°, and 128.12° ( I ) and 2.104(2)–2.109(3) and 2.136(2) Å and 108.38°, 108.38°, and 143.23° ( II ), respectively. Sb⋯O=(C) intramolecular contacts are 3.357(3) Å ( I ) and 2.919(5) Å ( II ).