Iodosyl sulfate

The parent iodine(III) oxide, I2O3, is unknown however, several its inorganic derivatives of types OIOR or I(0R)3 have been reported in the literature. Historically, the first of these derivatives was iodosyl sulfate, (10)2804, which was first isolated as early as 1844 [20]. Iodosyl sulfate and the selenate, (I0)2Se04, can be prepared by the interaction of iodine with iodine pentoxide in concentrated sulfuric or selenic acid [4,21,22]. A convenient procedure for the preparation of iodosyl sulfate by heating iodine and sodium metaperiodate, NaI04, in concentrated sulfuric acid was reported by Kraszkiewicz and Skulski in 2008 [23]. X-Ray crystallographic analysis of iodosyl sulfate shows a polymeric structure with infinite (-0-I -0-) spiral chains linked by SO4 tetrahedra [24]. Studies of (10)2804 by IR and Raman spectroscopy in the solid state [22] and by cryoscopic and conductometric measurements of the solution in sulfuric acid [25], were also reported. 

Iodosyl fluorosulfate, OIOSO2F and the triflate, OIOTf, can be prepared as thermally stable, hygroscopic yellow solids by the reaction of iodine with iodine pentoxide or iodic acid in fluorosulfonic or trifluoromethanesulfonic acids, respectively [5]. Raman and infrared spectra of these compounds indicate a polymeric structure analogous to iodosyl sulfate [5], Iodine tris(fluorosulfate), I(0S02F)3 and tris(triflate), I(OTf)3, are also known [6,26]. I(0S02F)3 can be prepared by the reaction of iodine with peroxydisulfuryl ditluoride [26]. Salts such as KI(0S02F)4 have also been prepared and investigated by Raman spectroscopy [26,27]. I(OTf)3 was prepared from iodine tris(trifluoroacetate) and trifluoromethanesulfonic acid [6]. 

Symmetrical iodonium salts. Arenes, including non-activated compounds such as nitrobenzene, react with the powerful electrophile iodosyl fluorosulfate (FS020I0, obtained from iodine, iodine pentoxide and fluorosulfonic acid) to give directly diaryliodonium hydro sulfates. The reaction is performed at low temperature (Scheme 32) [97]. 

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