Preparation and Characterization of Preyssler-type Phosphotungstic Acid, H15n[P5W30O110Mn], with Different Encapsulated Cations (M = Na, Ca, Bi, Eu, Y, or Ce), and their Thermal Stability and Acid Catalyst Properties

作者：Takahashi Keita; Sano Tsuneji; Sadakane Masahiro^*

来源：Zeitschrift fur Anorganische und Allgemeine Chemie, 2014, 640(7): 1314-1321.

DOI：10.1002/zaac.201400038

• Polyanion
• Acidity
• Tungsten
• Heteropolyacid
• Acid catalyst

Preyssler-type phosphotungstic acid, H15-n[P5W30O110Mn+], with different encapsulated cations (M = Ca2+, Bi3+, Eu3+, Y3+, Ce3+) were prepared and characterized using P-31 NMR and IR spectroscopy, acid-base titration, and elemental analyses. The pK(a) value of an internal proton of Ca-encapsulated derivative, [P5W30O110CaHin](12-), was estimated to be 5.9. Their thermal stabilities and acid catalyst properties were compared with a parent Na-encapsulated Preyssler-type phoshotungstic acid, H-14[P5W30O110Na]. Thermal stability of the Preyssler-type molecule was increased by exchanging the encapsulated Na+ with Bi3+, Eu3+, or Ce3+, with keeping their high acidic properties.

• 出版日期2014-6