On the electronic and atomic structures of small AuN- (N=4-14) clusters:: A photoelectron spectroscopy and density-functional study
On the electronic and atomic structures of small AuN- (N=4-14) clusters:: A photoelectron spectroscopy and density-functional study
复制标题
DOI：
10.1021/jp035437i
复制
发表时间：
2003-08-14
影响因子：
2.9
通讯作者：
Wang, LS
中科院分区：
文献类型：
--
作者：
Häkkinen, H;Yoon, B;Wang, LS
我们报道了对最多14个原子的小金团簇的电子结构和原子结构的联合实验和理论研究。在几个光子能量下获得了Au-N(-)(N=1-14)的高分辨光电子能谱。观察到偶数尺寸的团簇(除Au-10(-)外)在最低结合能峰和光谱的其余部分之间显示出能隙，表明所有中性的偶数尺寸的团簇都有闭合的壳层。Au-10(-)谱揭示了异构体的存在，基态团簇表现出极高的电子结合能。在N=4，8，12和13的光谱中也观察到了多异构体的证据。用第一性原理模拟方法研究了N=4-14范围内的金团簇阴离子的结构。在这个范围内的阴离子团簇的一个显著特征是出现平面基态结构，这是在早期的理论研究中预测的(Hakkinen，H.；等人)。太棒了。莱特牧师。2002年，89,033401)，并在离子迁移率实验中观察到(Furche，F.；et al.J·化学。太棒了。2002、117、6982)和近距离同分异构体的存在。将计算的电子脱离能和态密度与实验数据进行了比较，证实了阴离子的基态结构。实验发现，实验观察到的主要异构体确实由平面团簇组成，直到Au-12(-)，而对于Au-13(-)和Au-14(-)，三维异构体的理论结果与实验结果更符合，进一步支持了以前的离子迁移率实验所得出的Au-12(-)处的2D到3D结构转变。我们还发现，较小的中性团簇有形成高达13个原子的二维结构的趋势。
We report a joint experimental and theoretical study of the electronic and atomic structures of small gold clusters with up to 14 atoms. Well-resolved photoelectron spectra were obtained for Au-N(-) (N = 1-14) at several photon energies. Even-odd alternations were observed, where the even-sized clusters (except Au-10(-)) exhibit an energy gap between the lowest binding energy peak and the rest of the spectrum, indicating that all the neutral even-sized clusters have closed shells. The Au-10(-) spectrum reveals the existence of isomers, with the ground-state cluster exhibiting an extremely high electron binding energy. Evidence of multiple isomers was also observed in the spectra of N = 4, 8, 12, and 13. The structures of the gold cluster anions in the range N = 4-14 were investigated using first-principles simulations. A striking feature of the anionic clusters in this range is the occurrence of planar ground-state structures, which were predicted in earlier theoretical studies (Hakkinen, H.; et al. Phys. Rev. Lett. 2002, 89, 033401) and observed in ion-mobility experiments (Furche, F.; et al. J. Chem. Phys. 2002, 117, 6982) and the existence of close-lying isomers. The calculated electron detachment energies and density of states were compared with the measured data, which confirmed the ground-state structures of the anions. It is found that the main isomers observed experimentally indeed consist of planar clusters up to Au-12(-), Whereas for Au-13(-) and Au-14(-) the theoretical results from three-dimensional isomers agree better with the experiment, providing further support for the 2D to 3D structural transition at Au-12(-), as concluded from previous ion mobility experiments. We also find that small neutral clusters exhibit a tendency to form two-dimensional structures up to a size of 13 atoms.