Synthesis and Characterization of Metal Oxalatophosphonates and Uranium Silicates and Germanates
博士 === 國立中央大學 === 化學研究所 === 97 === There are six metal oxalatophosphonates and seven uranium silicates and germanates introduced in this thesis. Two of them were obtained via flux-growth method and the others were synthesized under hydrothermal method. These compounds have divided into two series by...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2009
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| Online Access: | http://ndltd.ncl.edu.tw/handle/82063747495364717761 |
| Summary: | 博士 === 國立中央大學 === 化學研究所 === 97 === There are six metal oxalatophosphonates and seven uranium silicates and germanates introduced in this thesis. Two of them were obtained via flux-growth method and the others were synthesized under hydrothermal method. These compounds have divided into two series by their components.
The first series (A1 to A6) represents metal oxalatophosphonates which has been synthesized under mild hydrothermal conditions. We highlight two conclusions of first serise as follows: (a) A1 is the first organically templated gallium oxalatophosphonate. (b) The A5 has a 2D layer structure and the A6 adopts a 1D chain structure. These two compounds contain different hydrogen bond to form 3D frameworks.
The second series (B1 to B7) describes seven uranium silicates and germanates which have been synthesized under high-temperature, high-pressure hydrothermal conditions or flux-growth method. We extract some conclusions as below: (a) B1 and B2 contain three parallel strings of a-UF5 type, which are joined via common corners to form a uranate column with the composition (UO2/2O2/2O2/1)3. This uranate column only occur in U(Ⅴ) compound. (b) B3 and B4 are the first examples of mixed-valence uranium(V,VI) germinates and their structures consist of strings of UO6 polyhedra sharing common corners to give infinite –U6+–O–U5+–O–U6+– chains. (c) B5 is a highly thermal stable extra-large pore uranyl germanate which is stable to 700 °C in air and is able to absorb water reversibly. (d) B6 and B7 are lithium uranyl silicate and germanate.
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