叶绿素a-富勒烯分子结的电荷转移过程及其电学特性研究

项目名称： 叶绿素a-富勒烯分子结的电荷转移过程及其电学特性研究

项目编号： No.10804041

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 生物科学

项目作者： 王立

作者单位： 南昌大学

项目金额： 24万元

中文摘要： 本项目着眼于生物分子以及平面共轭分子在新型光电转换器件中的应用，特别关注叶绿素a、富勒烯以及红荧烯、酞菁锌这四种典型分子在各类固体表面上的单分子层薄膜以及其构成的分子结的构筑。在超高真空环境下，通过有机分子分子束淀积技术，在硅、金、铜等表面实现了上述单分子层的构筑，利用扫描隧道显微技术，实现了对所构筑的单分子层薄膜以及分子结的结构表征，研究了上述薄膜和分子结的形成机制。在室温条件下，表征了单个富勒烯分子在硅（111）表面上的吸附几何结构，并通过针尖实现了对富勒烯分子的吸附位点、在面内取向以及吸附状态的调控。制备了红茵烯超分子手性结构，揭示了分子间作用力对手性结构的影响，实现了手性在层间的传递；也利用同步辐射光电子谱阐明了氧化过程对红茵烯薄膜电子结构的影响，提出了结构缺陷所导致的带间态模型。在室温下观测了吸附在铜（100）表面的酞菁锌分子的手性特征，揭示了该类手性来源于酞菁锌与铜表面之间的非对称电荷转移，展示了该类手性具有自我手性识别的特点以及识别机制。上述研究成果对基于有机分子的器件设计以及手性提纯和催化具有重要的参考价值，共在Appl. Phys.lett.等杂志发表SCI论文5篇。

中文关键词： 单分子层；吸附几何结构；手性；超分子结构

英文摘要： Formation of monolayers and junctions consisting of biomolecules and conjugated molecules including chlorophyll a，fulleren,rubrene and znic phthalocyanine (ZnPc) on various solid surfaces have been systematically investigated by scanning tunneling microscopy (STM) and synchrotron-based photoemission spectroscopy (PES). Adsorption geometry of single fullerene on Si(111)-(7x7) surface have been clearly observed at room temperature for the first time, and the adsorption status, in-plane orientation and adsorption site of single fullerene on Si surfaces can be controlled by a STM tip. Formation of rubrene chiral supramolecular structures has been achieved on Au(111) surface and such chirality can be transferred from the bottom layer to the upper layer, at least five layers. PES studies reveal that incorporation of oxygen atoms into rubrene films significantly influences the electronic properties of the films and induces a deep state within the valence band. The oxided rubrene molecules in a single crystal are proposed to act as point defects that disturb the long-range periodicity and produce localized acceptor states. The windmill-like chiral nature of individual ZnPc molecules adsorbed on Cu(100) surface at room temperature have been revealed by STM and the origin of such chirality is attributed to asymmetrical charge transfer between the molecules and the copper surface. Such chiral enantionmers do recognize each other in molecular level and spontaneously form second-level chiral supramolecular structures with the same chirality during thermally-driven movements. These results generate 5 SCI publications in top journals including Appl. Phys. Lett. and Phys. Chem. Chem. Phys. and may be invaluable to the optimization of devices based on organic molecule, enantio-selective catalysis and chiral separation.

英文关键词： monolayer;adsorption geometry;chirality;supramolecular structures