4-Sulfophenylphosphonic Acid:  A Novel Precursor to Fabricate Polyfunctional Acid Materials

Abstract

A major application of polyfunctional acid materials is the fabrication of solid electrolytes exhibiting proton conductivity in the solid state for operation in fuel cells at medium temperature (<160°C). Because the advancement of research on solid proton conductors depends on the availability of new precursors, a new acid organosulphur phosphorus compound, i.e., the hydrated 4-sulfophenylphosphonic acid H 2 O 3 -PC 6 H 4 SO 3 H 2 ‚2 H 2 O (IA), has been synthesized by the Tavs reaction starting from the 4-bromo(diethyl)-sulfonate precursor. This synthetic route is opposite that reported for the synthesis of many other aromatic sulfophosphonic acids, which are obtained by sulfonation of the aromatic phosphonic acid precursor. The reason for the different synthetic route in the former case lies in the fact that sulfonation of benzenephosphonic acid yields only metasubstituted derivatives. Investigation of the solid-state structure at variable temperature indicates that IA yields the anhydrous compound H 2 O 3 PC 6 H 4 SO 3 H 2 (IB) at 190-210°C. Solid state 13 C and 31 P NMR data and FT-IR measurements are consistent with intermolecular H-bonding between the sulfonic and phosphonic acid groups, and/or protonation of the phosphonic acid by the sulfonic acid group, depending on the presence of water. Ar-These interactions are very important in determining proton conductivity in relation to the possible use of IA as solid electrolyte component in fuel cells operating at medium temperature. On this basis, 4-sulfophenylphosphonic acid seems an interesting precursor for the fabrication of solid proton conducting electrolytes.

Systematic Hydrothermal Investigation of Metal Phosphonatobenzenesulfonates by High‐Throughput Methods

“…[53] All other reagents were of analytical grade (Aldrich and ABCR) and used without further purification. High-throughput XRPD experiments were carried out in transmission mode using a STOE high-throughput powder diffractometer equipped with an image-plate position-sensitive detector (IPPSD).…”

Synthesis and characterization of new zirconium 4-sulfophenylphosphonates

“…Up to now, only 3-sulfophenylphosphonates were investigated, as 3-sulfophenylphosphonic acid can be prepared directly by sulfonation of phenylphosphonic acid [1]. Recently, 4-sulfophenylphosphonic acid has been synthesized from ethyl 4-bromobenzenesulfonate by the reaction with triethylphosphite in the presence of NiCl 2 (the Tavs reaction) [2]. Its use for the preparation of metal phosphonates has not been reported up to now, to the best of our knowledge.…”

“…From the numerous studies of these zirconium phosphonates it was inferred that the structure of these compounds is derived from the structure of alpha modification of zirconium hydrogen phosphate monohydrate, Zr(HPO 4 )·H 2 O, in which the OH group is replaced by an organic radical.…”

“…In this paper, we report on the preparation of 4-sulfophenylphosphonic acid in a way different from that described previously [2] and on the synthesis of zirconium 4-sulfophenylphosphonate and zirconium phosphate sulfophenylphosphonate. These phosphonates were characterized using X-ray powder diffraction, thermogravimetry, IR spectroscopy, and solid-state NMR and their protonic conductivity was also investigated.…”

Synthesis of meta and para-substituted aromatic sulfonate derivatives of polydentate phenylazaphosphinate ligands: enhancement of the water solubility of emissive europium(iii) EuroTracker® dyes

“…4 Classically, aryl sulfonation occurs under forcing electrophilic conditions and the methods used for CH functionalisation are generally not suitable for multifunctional compounds with electron-rich or nucleophilic groups. 5 Therefore, various strategies have been devised to create suitable sulfonate protecting groups, typically using electron poor or sterically hindered sulfonate esters (e.g CH 2 CX 3 , X = F, Cl; neopentyl) to suppress the nucleophilic substitution reaction that may cleave the C-O bond.…”