Structural determination of niobium-doped silicon clusters by far-infrared spectroscopy and theory.
Structural determination of niobium-doped silicon clusters by far-infrared spectroscopy and theory.
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DOI：
10.1039/c5cp07298k
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发表时间：
2016-02
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通讯作者：
Xiaojun Li;P. Claes;M. Haertelt;P. Lievens;E. Janssens;A. Fielicke
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文献类型：
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作者：
Xiaojun Li;P. Claes;M. Haertelt;P. Lievens;E. Janssens;A. Fielicke
本文采用红外多光子解离（IR-MPD）和密度泛函理论（DFT）相结合的方法，研究了SinNb（+）（n = 4-12）团簇的结构.通过与使用随机“随机踢”算法结合BP 86 GGA泛函识别的SinNb（+）的低能结构的计算IR光谱进行比较，对SinNb（+）的氩络合物的实验IR-MPD光谱进行了分配。发现Nb掺杂剂倾向于结合在Sin骨架的顶点位置（n = 4-9）和具有高配位数的表面位置（n = 10-12）。对于较大的掺杂团簇，它建议，多种异构体共存，并有助于实验光谱。SinNb（+）团簇的结构演化类似于V掺杂的硅团簇（J. Am.化学会，2010，132，15589-15602），除了所研究的最大尺寸（n = 12），因为V在Si 12 V（+）中占据内面位置。与Nb原子及其部分未填充的4d轨道的相互作用导致Sin框架的显著稳定性增强，如例如通过高结合能和大HOMO-LUMO间隙所反映的。
In this work, the structures of cationic SinNb(+) (n = 4-12) clusters are determined using the combination of infrared multiple photon dissociation (IR-MPD) and density functional theory (DFT) calculations. The experimental IR-MPD spectra of the argon complexes of SinNb(+) are assigned by comparison to the calculated IR spectra of low-energy structures of SinNb(+) that are identified using the stochastic 'random kick' algorithm in conjunction with the BP86 GGA functional. It is found that the Nb dopant tends to bind in an apex position of the Sin framework for n = 4-9 and in surface positions with high coordination numbers for n = 10-12. For the larger doped clusters, it is suggested that multiple isomers coexist and contribute to the experimental spectra. The structural evolution of SinNb(+) clusters is similar to V-doped silicon clusters (J. Am. Chem. Soc., 2010, 132, 15589-15602), except for the largest size investigated (n = 12), since V takes an endohedral position in Si12V(+). The interaction with a Nb atom, with its partially unfilled 4d orbitals leads to a significant stability enhancement of the Sin framework as reflected, e.g. by high binding energies and large HOMO-LUMO gaps.