Polymorphism of triphenylantimony(V) bis-cumylperoxide

Two polymorphs of triphenylantimony(V) bis-cumylperoxide were obtained by the interaction of triphenylantimony(V) dihalides with cumene hydroperoxide in an aromatic hydrocarbon in the presence of ammonia or aqueous potassium hydroxide solution. The structure of two polymorphic modifications I and II was determined by the single crystal X-ray diffraction analysis, revealing the crystallization in monoclinic P2₁/n and P2₁/c space groups, respectively, with Z = 4. To our knowledge, this is the first report of polymorphism of peroxo complexes. The polymorph I was characterized by elemental and thermal analyses, Fourier transform infrared and Raman spectroscopies, and powder X-ray diffraction. Analysis of crystal structure databases revealed the similarity between peroxide, hydroperoxide, and organoperoxide ligands in the corresponding p-block element complexes.