Site-selective halogenation of mixed-valent vanadium oxide clusters
Site-selective halogenation of mixed-valent vanadium oxide clusters
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DOI：
10.1039/d0dt01077d
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发表时间：
2020-12-07
影响因子：
4
通讯作者：
Matson, Ellen M.
中科院分区：
文献类型：
--
作者：
Maiola, Michela L.;Petel, Brittney E.;Matson, Ellen M.
在这里，我们扩展了氯官能化多钒酸盐-醇氧化物（pov -醇氧化物）簇的合成和表征，包括混合价钒氧化物的卤化。这些发现建立在我们之前披露的结果的基础上，描述了通过用AlCl3氯化[V6O7(OC2H5)(12)]（2-）制备单阴离子氯化物功能化簇[V6O6Cl(OC2H5)(12)](1-)，旨在了解大块金属氧化物（例如VO2）中引入卤化物缺陷的电子后果。虽然用AlCl3不能氯化化混合价pov -乙氧化物簇，但我们发现可以用TiCl3(thf)(3)与[V6O7(OC2H5)(12)](n) （n = 1-, 0）或WCl6与[V6O7(OC2H5)(12)](0)形成Lindqvist氧化钒簇的氯代氧化衍生物。含氯产物[V6O6Cl(OC2H5)(12)](n) （n = 0,1 +）的表征通过(1)H NMR波谱、x射线晶体学和元素分析完成。通过红外和电子吸收光谱对掺杂cl的pov -醇氧化合物簇的氧化还原系列进行了电子分析，发现所有的氧化还原事件都局限于簇的钒基部分，在1.9 V的窗口内，位点分化的V- iii - cl部分保持其还原氧化态。这些结果为从混合价氧化钒前驱体中获得氯掺杂pov -醇氧化合物簇提供了新的合成途径。
Here, we expand on the synthesis and characterization of chloride-functionalized polyoxovanadate-alkoxide (POV-alkoxide) clusters, to include the halogenation of mixed-valent vanadium oxide assemblies. These findings build on our previously disclosed results describing the preparation of a mono-anionic chloride-functionalized cluster, [V6O6Cl(OC2H5)(12)](1-), by chlorination of [V6O7(OC2H5)(12)](2-) with AlCl3, aimed at understanding the electronic consequences of the introduction of halide-defects in bulk metal oxides (e.g. VO2). While chlorination of the mixed-valent POV-ethoxide clusters was not possible using AlCl3, we have found that the chloride-substituted oxidized derivatives of the Lindqvist vanadium-oxide clusters can be formed using TiCl3(thf)(3) with [V6O7(OC2H5)(12)](n) (n = 1-, 0) or WCl6 with [V6O7(OC2H5)(12)](0). Characterization of the chloride-containing products, [V6O6Cl(OC2H5)(12)](n) (n = 0, 1+), was accomplished via(1)H NMR spectroscopy, X-ray crystallography, and elemental analysis. Electronic analysis of the redox series of Cl-doped POV-alkoxide clusters via infrared and electronic absorption spectroscopies revealed all redox events are localized to the vanadyl portion of the cluster, with the site differentiated V-III-Cl moiety retaining its reduced oxidation state across a 1.9 V window. These results present new synthetic routes for accessing chloride-doped POV-alkoxide clusters from mixed-valent vanadium oxide precursors.