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Preparation and Characterization of Preyssler‐type Phosphotungstic Acid, H 15– n [P 5 W 30 O 110 M n + ], with Different Encapsulated Cations ( M = Na, Ca, Bi, Eu, Y, or Ce), and their Thermal Stability and Acid Catalyst Properties
Ist Teil von
Zeitschrift für anorganische und allgemeine Chemie (1950), 2014-06, Vol.640 (7), p.1314-1321
Erscheinungsjahr
2014
Link zum Volltext
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
Abstract
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.