O-centered tetranuclear vanadium selenoiodide [V₄OSe₈I₅]_∞ (1) was synthesized by an ampoule method from the elements with addition of water. Its X-ray crystal structure (space group C2/c, a = 21.146(2) Å, b = 5.8953(5) Å, c = 18.735(1) Å, β = 126.421(2)°, V = 1879.4(3) ų, T = 150 K, Z = 4) is a packing of chains built from O-centered tetranuclear [V₄(μ₄-O)(μ-Se₂)₄(μ₄-I)_2/2I₄] fragments. In the O-centered fragment, vanadium atoms form a distorted tetrahedron around an oxygen atom, V atoms are bridged by four μ₂-(Se₂)²⁻ and two I⁻ ligands. The latter iodide ligands bridge the neighboring fragments, thus forming a chain [V₄(μ₄-O)(μ-Se₂)₄(μ₄-I)_2/2I₄]_∞. The synthesis of the chain [V₄OSe₈I₅]_∞ takes place at the temperature of 290 °C, while at lower temperatures (220–250 °C) molecular compounds [V₄OSe₈I₆]·X form. The direct ‘cluster to chain’ transformation is also observed and discussed in this work. Electrical resistance of the [V₄OSe₈I₅]_∞ polycrystalline pressed sample shows that the compound 1 is a narrow gap semiconductor, which is in agreement with the DFT calculations.

中文翻译：

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钒 O 中心配合物 [V4OSe8I5]∞ 中的延长链：合成和结构


O 中心四核硒代碘化钒 [V4OSe8I5]∞ （1） 是通过安瓿法从添加水的元素合成的。其 X 射线晶体结构（空间群 C2/c，a = 21.146（2） Å，b = 5.8953（5） Å，c = 18.735（1） Å，β = 126.421（2）°，V = 1879.4（3） Å3，T = 150 К，Z = 4）是由 O 中心四核 [V4（μ4-O）（μ-Se2）4（μ4-I）2/2I4] 碎片构成的链堆积。在 O 中心碎片中，钒原子围绕氧原子形成扭曲的四面体，V 原子由四个 μ2-（Se2）2– 和两个 I– 配体桥接。后者的碘化物配体与相邻的片段桥接，从而形成一条链 [V4（μ4-O）（μ-Se2）4（μ4-I）2/2I4]∞。链 [V4OSe8I5]∞ 的合成发生在 290°С 的温度下，而在较低的温度 （220-250°С） 下，分子化合物 [V4OSe8I6]·X 形式。这项工作还观察和讨论了直接的 “集群到链 ”转换。[V4OSe8I5]∞ 多晶压制样品的电阻表明化合物 1 是窄间隙半导体，这与 DFT 的计算结果一致。