Tungsten iodide compounds feature a surprising diversity of binary compounds. Their formation conditions and phase equilibria depend very much on the surrounding iodine partial pressure and temperature. Herein we focus on square-pyramidal tungsten iodide cluster compounds with their iodine loss, structural rearrangements, cross-linking behavior, and final transformation into the octahedral cluster compound β-W₆I₁₂ at elevated temperatures. Reactions depart from W₅I₁₆ at different iodine pressures and temperatures. The thermal decomposition of W₅I₁₆ at low iodine pressure passes through a number of cluster compounds (W₅I₁₅, W₅I₁₃·xI₂, β-W₅I₁₂, and W₅I₁₁) under release of iodine. At higher iodine pressures, only one intermediate compound (α-W₅I₁₂) was found. Thermal decomposition of W₅I₁₆ was examined by differential thermal/thermogravimetric analysis, differential scanning calorimetry, and X-ray diffraction (XRD) measurements. New compounds (W₅I₁₅, W₅I₁₃·xI₂, and W₅I₁₁) were structurally characterized by means of XRD techniques. The crystal structure of W₅I₁₁ reveals a nice relationship to its transformation product W₆I₁₂.

中文翻译：

---

W ₅ I _16的碘热损失级联

碘化钨化合物具有令人惊讶的二元化合物多样性。它们的形成条件和相平衡在很大程度上取决于周围的碘分压和温度。本文我们专注于四方锥碘化钨簇化合物与他们的碘损失，结构重排，交联行为，并最终转变成八面体簇化合物β-W ₆余₁₂在升高的温度下。反应在不同的碘压力和温度下从W ₅ I ₁₆离开。W ₅ I ₁₆在低碘压力下的热分解通过许多簇化合物（W ₅ I ₁₅，W₅余₁₃ · X我₂，β-W ₅余₁₂，和W ₅余₁₁下的碘释放）。在较高的压力下碘，只有一个中间化合物（α-W ₅余₁₂）被发现。W ₅ I _16的热分解通过差示热/热重分析，差示扫描量热法和X射线衍射（XRD）测量进行了检查。新化合物（W ₅ I ₁₅，W ₅ I ₁₃ · x I ₂和W ₅ I ₁₁）通过XRD技术进行结构表征。W ₅ I ₁₁的晶体结构与其转化产物W ₆ I _12表现出良好的关系。