Abstract—

This paper reports the synthesis of compounds with the pyrochlore and hexagonal tungsten bronze structures via thermal decomposition of heteropolyoxometalates. Using aqueous solutions, we have synthesized tungstophosphatometalates with the Keggin structure and the general formula Ct₅[PW₁₁O₃₉(H₂O)Z]⋅nH₂O, where Ct = Rb⁺ or Cs⁺ and Z = Co²⁺, Ni²⁺, or Cu²⁺. We have studied the thermal decomposition of these compounds and identified their thermolysis products: phases with the pyrochlore and hexagonal tungsten bronze structures. Our results confirm that phosphorus, cobalt, nickel, and copper ions become incorporated into the pyrochlore and hexagonal tungsten bronze structures of the Ct_nxP_xZ_xW_2–2xO₆ compounds. No phases with similar chemical compositions have been reported previously. Their synthesis temperature has been lowered by 200°C and the calcination time has been reduced by a factor of 2 in comparison with conventional synthesis methods. The proposed schemes of thermolysis of rubidium and cesium tungstophosphatometalates will be useful for predicting the thermal properties and phase composition of thermolysis products of analogous heteropolyoxometalates in designing new inorganic materials based on them.

中文翻译：

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烧绿石和六方钨青铜结构化合物的低温合成

摘要——

本文报道了通过杂多金属氧酸盐的热分解合成具有烧绿石和六方钨青铜结构的化合物。使用水溶液，我们合成了具有 Keggin 结构和通式 Ct ₅ [PW ₁₁ O ₃₉ (H ₂ O)Z]⋅ n H ₂ O，其中 Ct = Rb ⁺或 Cs ⁺和 Z = Co ²⁺ , Ni ²⁺ , 或 Cu ²⁺. 我们研究了这些化合物的热分解并确定了它们的热分解产物：具有烧绿石和六方钨青铜结构的相。我们的结果证实磷、钴、镍和铜离子被结合到 Ct _nx P _x Z _x W _{2–2 x} O ₆的烧绿石和六方钨青铜结构中化合物。以前没有报道过具有类似化学成分的相。与传统合成方法相比，它们的合成温度降低了 200°C，煅烧时间减少了 2 倍。提出的铷和钨磷金属酸铯热解方案将有助于预测类似杂多金属氧酸盐的热解产物的热性质和相组成，从而设计基于它们的新无机材料。