Synthesis and X-Ray Crystal Structure of the First Pure and Air-Stable Salt of Peroxymonosulphuric Acid: (Ph)4PHSO5

Abstract

Abstract:In this paper we describe the synthesis of tetraphenylphosphonium peroxymonosulphate, its crystal structure and packing mode. The asymmetric unit accomodates two independent molecules of the monopersulphate anion, which are held together by hydrogen bonds. In the packing mode, rows of such dimers are surrounded by four rows of tetraphenyl cations. The consequence is that the highly water sensitive HSO 5¯ anions are segregated inside hydrophobic channels composed by the lipophilic cations. This circumstance presumably accounts for the exceptional stability of the title compound.

Crystal Structure and Chemical Stabilization of the Triple Salt (KHSO5)2⋅KHSO4⋅K2SO4

“…That this enhanced, i.e., higher than one-dimensional, shielding of the HSO À 5 ions can be realized in the crystals of 1 is clearly due to the triple salt×s stoichiometric richness in K and the comparatively large size of these cations. Recently, tetraphenylphosphonium hydrogenperoxomonosulfate was reported to be chemically well-stabilized since, here, the bulky cations assemble in the crystal to form segregated channels in which the HSO À 5 ions are lined up [8]. Thus, in this case the hydrogenperoxomonosulfate anions are two-dimensionally shielded from chemical attack, ensuring effective protection.…”