Wang Ling-Fei, Xie Lu, Fang Hong-Ling, Li Yun-Fei, Zhang Xiao-Bin, Wang Bin, Zhang Yong-Fan, Huang Xin
Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, PR China.
Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, Fujian 361005, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Oct 15;131:446-54. doi: 10.1016/j.saa.2014.04.094. Epub 2014 Apr 30.
Density functional theory (DFT) calculations are carried out to investigate the structural and electronic properties of a series of hexanuclear vanadium oxide clusters V6On(-/0) (n=12-15). Generalized Koopmans' theorem is applied to predict the vertical detachment energies (VDEs) and simulate the photoelectron spectra (PES) for V6On(-) (n=12-15) clusters. Extensive DFT calculations are performed in search of the lowest-energy structures for both the anions and neutrals. All of these clusters appear to prefer the polyhedral cage structures, in contrast to the planar star-like structures observed in prior model surface studies for the V6O12 cluster. Molecular orbitals are performed to analyze the chemical bonding in the hexanuclear vanadium oxide clusters and provide insights into the sequential oxidation of V6On(-) (n=12-15) clusters. The V6On(-) (n=12-15) clusters possess well-defined V(5+) and V(3+) sites, and may serve as molecular models for surface defects. Electron spin density analyses show that the unpaired electrons in V6On(-) (n=12-14) clusters are primarily localized on the V(3+) sites rather than on the V(5+) sites. The difference gas phase versus model surface structures of V6O12 hints the critical roles of cluster-substrate interactions in stabilizing the planar V6O12 cluster on model surfaces.
进行密度泛函理论（DFT）计算以研究一系列六核钒氧化物簇V6On(-/0)（n = 12 - 15）的结构和电子性质。应用广义库普曼定理预测V6On(-)（n = 12 - 15）簇的垂直脱附能（VDE）并模拟光电子能谱（PES）。进行了大量DFT计算以寻找阴离子和中性分子的最低能量结构。与先前对V6O12簇的模型表面研究中观察到的平面星状结构相比，所有这些簇似乎都更喜欢多面体笼状结构。进行分子轨道分析以研究六核钒氧化物簇中的化学键，并深入了解V6On(-)（n = 12 - 15）簇的顺序氧化。V6On(-)（n = 12 - 15）簇具有明确的V(5+)和V(3+)位点，可作为表面缺陷的分子模型。电子自旋密度分析表明，V6On(-)（n = 12 - 14）簇中的未成对电子主要定域在V(3+)位点而非V(5+)位点上。V6O12的气相结构与模型表面结构的差异暗示了簇 - 底物相互作用在稳定模型表面上的平面V6O12簇中的关键作用。
