Publication Date:
2014-03-15
Description:
Preyssler-type phosphotungstic acid, H 15– n [P 5 W 30 O 110 M n + ], with different encapsulated cations ( M = Ca 2+ , Bi 3+ , Eu 3+ , Y 3+ , Ce 3+ ) were prepared and characterized using 31 P NMR and IR spectroscopy, acid-base titration, and elemental analyses. The p K a value of an internal proton of Ca-encapsulated derivative, [P 5 W 30 O 110 CaH in ] 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 [P 5 W 30 O 110 Na]. Thermal stability of the Preyssler-type molecule was increased by exchanging the encapsulated Na + with Bi 3+ , Eu 3+ , or Ce 3+ , with keeping their high acidic properties.
Print ISSN:
0044-2313
Electronic ISSN:
1521-3749
Topics:
Chemistry and Pharmacology
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