The structure of molten Na2W2O7 has been investigated by the radial distribution function based on X-ray scattered intensity data collected at ≈810°C and has been analysed by the correlation method. The coexistence of WO4 tetrahedra and WO 6 octahedra in molten Na2W2O7 is considered to be plausible. The mean W-O distance in the molten state is found to be 1.80 Å. Four models, i.e., three crystalline modification models: (1) Na2W2O7; (2) Li2W 2O7; (4) K2Mo2O7; and (3) W2O7 tetrahedral model, are examined by the correlation method. The possible model which gives the best agreement with the observed intensity curve of molten Na2W2O7 is concluded to be the Na2W2O7 crystalline model. The structure of the molten state almost preserves that of the crystalline state within the range r < 4.5 Å. The long-range order within one [(W 2O7)2-]∞ anion chain is suggested to be almost lost and and neighbouring chains may be almost randomly orientated with respect to one another in the molten state.
|Number of pages||5|
|Journal||Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics|
|Publication status||Published - Dec 1 1978|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry