Structural Phases of Ordered FePc-Nanochains Self-Assembled on Au(110)
Structural Phases of Ordered FePc-Nanochains Self-Assembled on Au(110)
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DOI：
10.1021/la302192n
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发表时间：
2012-09-18
期刊：
影响因子：
3.9
通讯作者：
Pedio, Maddalena
中科院分区：
文献类型：
--
作者：
Betti, Maria Grazia;Gargiani, Pierluigi;Pedio, Maddalena
沉积在Au（110）重构通道上的铁酞菁分子组装成一维分子链，随着分子密度的增加，其空间分布演变成不同的结构相。Au通道的可塑性首先诱导具有5 × 5对称性的有序相，然后是由相对于裸Au表面具有5 × 7周期性的密集链组成的第二长程有序结构，如在低能电子衍射（LEED）和掠入射X射线衍射（GIXRD）图案中观察到的。通过扫描隧道显微镜（STM）确定了FePc分子组装在Au纳米线中的几何形状。对于5 × 7相，GIXRD分析确定了Au表面沿[001]方向沿着的“4-3”行分布和顶部FePc吸附位点，密度泛函理论（DFT）计算进一步证实了这一点。后者还揭示了界面态的电子混合。链组装是由分子-分子相互作用驱动的，链通过中心金属原子与Au纳米轨道相互作用，而不同结构相中的链-链距离主要由Au表面的塑性驱动。
Iron-phthalocyanine molecules deposited on the Au(110) reconstructed channels assemble into one-dimensional molecular chains, whose spatial distribution evolves into different structural phases at increasing molecular density. The plasticity of the Au channels first induces an ordered phase with a 5X5 symmetry, followed by a second long-range ordered structure composed by denser chains with a 5X7 periodicity with respect to the bare Au surface, as observed in the low-energy electron-diffraction (LEED) and grazing incidence X-ray diffraction (GIXRD) patterns. The geometry of the FePc molecular assemblies in the Au nanorails is determined by scanning tunneling microscopy (STM). For the 5X7 phases, the GIXRD analysis identifies a "4-3" rows profile along the [001] direction in the Au surface and an on-top FePc adsorption site, further confirmed by density functional theory (DFT) calculations. The latter also reveals the electronic mixing of the interface states. The chain assembly is driven by the molecule-molecule interaction and the chains interact with the Au nanorails via the central metal atom, while the chain-chain distance in the different structural phases is primarily driven by the plasticity of the Au surface.