4-Sulfophenylphosphonic Acid: A Novel Precursor to Fabricate Polyfunctional Acid Materials
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- 作者：Enzo Montoneri ; Guido Viscardi ; Stefano Bottigliengo ; Roberto Gobetto ; Michele R. Chierotti ; Roberto Buscaino ; Pierluigi Quagliotto
- 刊名：Chemistry of Materials
- 出版年：2007
- 出版时间：May 15, 2007
- 年：2007
- 卷：19
- 期：10
- 页码：2671 - 2678
- 全文大小：117K
- 年卷期：v.19,no.10(May 15, 2007)
- ISSN：1520-5002
文摘
A major application of polyfunctional acid materials is the fabrication of solid electrolytes exhibitingproton conductivity in the solid state for operation in fuel cells at medium temperature (<160 
C). Becausethe 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 H2O3PC6H4SO3H2·2 H2O (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 aromaticsulfophosphonic 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 ofbenzenephosphonic acid yields only metasubstituted derivatives. Investigation of the solid-state structureat variable temperature indicates that IA yields the anhydrous compound H2O3PC6H4SO3H2 (IB) at 190-210 C. Solid state 13C and 31P NMR data and FT-IR measurements are consistent with intermolecularH-bonding between the sulfonic and phosphonic acid groups, and/or protonation of the phosphonic acidby the sulfonic acid group, depending on the presence of water. Ar-SO3-H3O+···O=P(Ar)(OH)2···
H2 
Ar-SO3-H3O+···O=P(Ar)(OH)-O-···H3O+; Ar-SO3-H3O+···O=P(Ar)(OH)2···H2 Ar-SO3-H2O···[HO-P(Ar)(OH)2]+···OH2; Ar-SO3-H2O···[HO-P(Ar)(OH)2]+····H2 Ar-SO3-H2O···(HO)2P(Ar)=O···H3O+; 
+ 2nH2O.These interactions are very important in determining proton conductivity in relation to the possible useof 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 conductingelectrolytes.
C). Becausethe 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 H2O3PC6H4SO3H2·2 H2O (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 aromaticsulfophosphonic 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 ofbenzenephosphonic acid yields only metasubstituted derivatives. Investigation of the solid-state structureat variable temperature indicates that IA yields the anhydrous compound H2O3PC6H4SO3H2 (IB) at 190-210 C. Solid state 13C and 31P NMR data and FT-IR measurements are consistent with intermolecularH-bonding between the sulfonic and phosphonic acid groups, and/or protonation of the phosphonic acidby the sulfonic acid group, depending on the presence of water. Ar-SO3-H3O+···O=P(Ar)(OH)2···H2 Ar-SO3-H3O+···O=P(Ar)(OH)-O-···H3O+; Ar-SO3-H3O+···O=P(Ar)(OH)2···H2 Ar-SO3-H2O···[HO-P(Ar)(OH)2]+···OH2; Ar-SO3-H2O···[HO-P(Ar)(OH)2]+····H2 Ar-SO3-H2O···(HO)2P(Ar)=O···H3O+; + 2nH2O.These interactions are very important in determining proton conductivity in relation to the possible useof 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 conductingelectrolytes.