Self-assembly of hydroxy(phenyl)iodonium ions in acidic aqueous solution: Preparation, and X-ray crystal structures of oligomeric phenyliodine(III) sulfates

The treatment of [(diacetoxy)iodo]benzene with sodium bisulfate leads to the formation of oligomeric cationic species resulting from self-assembly of hydroxy(phenyl)iodonium ions, [PhlOH] ⁺, in an aqueous acidic media. Depending on the Phl(OAc) ₂:NaHSO ₄ ratio, three new oligomeric products have been isolated and characterized by X-ray crystallography. The treatment of 5 equiv of Phl(OAc) ₂ with 1 equiv of NaHSO ₄-H ₂O affords the previously unknown μ-oxo-[bis(acetoxy)iodo]benzene,Phl(OAc)OI(OAc)Ph, which was structurally characterized by X-ray crystallography. In the solid-state, this μ-oxo product forms an isolated diamond-core dimeric structure with pentagonal-planar iodine centers. The interaction of Phl(OAc) ₂ with 1 equiv of NaHSO ₄· H ₂O affords a solid-state polymeric phenyliodine(lll) sulfate, [(PhlO) ₃ · SO ₃]n, in which bis(μ-oxo)triiodanyl dication repeat units are linked by sulfate anions. Three of these neighboring polymeric chains form pseudo triple-helix supramolecular structure, which translates along crystal-lographic b-axis. The reaction of Phl(OAc) ₂ with 3 equiv of NaHSO ₄ · H ₂O results in the formation of a tetrameric phenyliodine(lll) sulfate, Phl(OH)OSO ₂O(Ph)IOI(Ph)OSO ₂OI(OH)Ph, the solid state structure of which consists of μ-oxodiiodanyl dicationic species linked by sulfate anions to the terminal hydroxy(phenyl)iodonium groups. The pseudo double-helix structure of this compound formed by the strong intermolecular interactions between two neighbor μ-oxodiiodanyl dicationic fragments and four (per pseudo helix dimer) areas of sulfate anions to the terminal hydroxy(phenyl)iodonium groups interactions.