Luis Fernando Piedra-Garza - Jacobs University

Chapter I. Iso- and Heteropolyoxometalates. An Introduction
(a)
(b)
Figure 1.11 Tri- and Hexalacunary species of the Wells-Dawson polyanion
(a) [P 2 W 15 O 56 ] 12- , (b) [H 2 P 2 W 12 O 48 ] 12- .
1.2.5 The Henicosatungstodiphosphate and –arsenate
[X2W21O71(H2O)3] 6- (X = P V , As III ) polyanion and their mono- und
dilacunary derivatives
When two [A-α-PPV W9O 34]
units or two [B-α-As III W9O 33] units are bridged by
three octahedrally coordinated W atoms located in the equatorial plane in
sites that correspond to those of the α Keggin isomer, the [X W O (H O) ]
(X = P V , As III ) species are formed (Figure 1.12).
1, 57b, 64
2 21 71 2 3 n-
20