Tetratungsten oxide clusters W4O(n)(-/0) (n = 10-13): structural evolution and chemical bonding.
Tetratungsten oxide clusters W4O(n)(-/0) (n = 10-13): structural evolution and chemical bonding.
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DOI：
10.1021/jp909676s
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发表时间：
2010-02
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通讯作者：
Bin Wang;Wen-Jie Chen;Bo-Cun Zhao;Yongfan Zhang;Xin Huang
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文献类型：
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作者：
Bin Wang;Wen-Jie Chen;Bo-Cun Zhao;Yongfan Zhang;Xin Huang
采用密度泛函理论（DFT）计算研究了一系列氧化四钨簇W(4)O(n)(-/0) （n = 10-13）的电子和结构性质。应用广义库普曼定理预测了垂直剥离能并模拟了光电子能谱。化学计量W(4)O（12）团簇存在较大的能隙（约2.9 eV），达到体积值。计算表明，W(4)O(12)（-/0）具有平面八元环结构，其中每个钨原子与两个桥接O原子和两个末端O原子呈四面体配位。W(4)O(10)（-/0）和W(4)O(11)（-）可以看作分别从W(4)O(12)（-/0）中去除两个和一个末端O原子。W(4)O（11）中性是一个有趣的物种，它具有五桥结构。我们发现W(4)O(11)（-）含有一个局部的W（3+）位点，它可以很容易地与O(2)反应形成W(4)O(13)（-）簇，而相应的中性W(4)O（13）可以看作是用过氧O(2)单元取代W(4)O（12）中的末端氧。用分子轨道分析方法分析了氧化四钨团簇中的化学键，并阐明了它们的电子和结构演变。
Density functional theory (DFT) calculations are carried out to investigate the electronic and structural properties of a series of tetratungsten oxide clusters, W(4)O(n)(-/0) (n = 10-13). Generalized Koopmans' theorem is applied to predict the vertical detachment energies and simulate the photoelectron spectra (PES). A large energy gap (approximately 2.9 eV) is observed for the stoichiometric W(4)O(12) cluster, which reaches the bulk value. The calculations suggest that W(4)O(12)(-/0) have the planar eight-membered ring structures, in which each tungsten atom is tetrahedrally coordinated with two bridging O atoms and two terminal O atoms. W(4)O(10)(-/0) and W(4)O(11)(-) can be viewed as removing two and one terminal O atoms from W(4)O(12)(-/0), respectively. The W(4)O(11) neutral is an interesting species, which possesses the pentabridged structure. We show that W(4)O(11)(-) contains a localized W(3+) site, which can readily react with O(2) to form the W(4)O(13)(-) cluster, whereas the corresponding neutral W(4)O(13) can be viewed as replacing a terminal oxygen in W(4)O(12) by a peroxo O(2) unit. Molecular orbital analyses are performed to analyze the chemical bonding in the tetratungsten oxide clusters and to elucidate their electronic and structural evolution.