Two Alkali Metal Germanophosphates Na₃[Ge（OH）（PO₄）₂]·2H₂O and Li₂Na[GeO（HPO₄）（PO₄）]:Crystal Structures and Thermal Stability

【摘要】 Two new alkali metal germanophosphates, namely, Na₃[Ge（OH）（PO₄）₂]·2 H₂ O and Li₂Na[GeO（HPO₄）（PO₄）], have been prepared by solvothermal method, and their crystal structures were determined by single-crystal X-ray diffraction. The title two compounds crystalize in the same orthorhombic space group Pbcm（No. 57） and feature similar chain-like structure which is built from zig-zag GeO₆ octahedral thread loop branched by PO₄ tetrahedra. For Na₃[Ge（OH）（PO₄）₂]·2 H₂ O, a = 10.1650（9）, b = 13.1975（12）, c = 6.9751（7） ?, V = 935.73（15） ?³, Z = 4, R = 0.0356 and wR = 0.1109; and for Li₂ Na[GeO（HPO₄）（PO₄）], a = 6.9855（5）, b = 14.5809（18）, c = 6.6620（5） ?, V = 678.56（11） ?³, Z = 4, R = 0.0286, and w R = 0.0762. The partial substitution of Na ions by Li ions not only significantly influences the total structural features and the water molecule contents, but also impacts on their thermal stabilities. Li₂ Na[GeO（HPO₄）（PO₄）] is thermally stable up to 400 ℃, whereas only 150 ℃ for Na₃[Ge（OH）（PO₄）2]·2 H₂ O.更多还原

【Abstract】 Two new alkali metal germanophosphates, namely, Na₃[Ge（OH）（PO₄）₂]·2 H₂ O and Li₂Na[GeO（HPO₄）（PO₄）], have been prepared by solvothermal method, and their crystal structures were determined by single-crystal X-ray diffraction. The title two compounds crystalize in the same orthorhombic space group Pbcm（No. 57） and feature similar chain-like structure which is built from zig-zag GeO₆ octahedral thread loop branched by PO₄ tetrahedra. For Na₃[Ge（OH）（PO₄）₂]·2 H₂ O, a = 10.1650（9）, b = 13.1975（12）, c = 6.9751（7） ?, V = 935.73（15） ?³, Z = 4, R = 0.0356 and wR = 0.1109; and for Li₂ Na[GeO（HPO₄）（PO₄）], a = 6.9855（5）, b = 14.5809（18）, c = 6.6620（5） ?, V = 678.56（11） ?³, Z = 4, R = 0.0286, and w R = 0.0762. The partial substitution of Na ions by Li ions not only significantly influences the total structural features and the water molecule contents, but also impacts on their thermal stabilities. Li₂ Na[GeO（HPO₄）（PO₄）] is thermally stable up to 400 ℃, whereas only 150 ℃ for Na₃[Ge（OH）（PO₄）2]·2 H₂ O.更多还原