Tebikachew Behabitu E, Li Haipeng B, Pirrotta Alessandro, Börjesson Karl, Solomon Gemma C, Hihath Joshua, Moth-Poulsen Kasper
Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden.
Department of Electrical and Computer Engineering, University of California Davis, Davis, California 95616, United States.
J Phys Chem C Nanomater Interfaces. 2017 Apr 6;121(13):7094-7100. doi: 10.1021/acs.jpcc.7b00319. Epub 2017 Mar 6.
Integrating functional molecules into single-molecule devices is a key step toward the realization of future computing machines based on the smallest possible components. In this context, photoswitching molecules that can make a transition between high and low conductivity in response to light are attractive candidates. Here we present the synthesis and conductance properties of a new type of robust molecular photothermal switch based on the norbornadiene (NB)-quadricyclane (QC) system. The transport through the molecule in the ON state is dominated by a pathway through the π-conjugated system, which is no longer available when the system is switched to the OFF state. Interestingly, in the OFF state we find that the same pathway contributes only 12% to the transport properties. We attribute this observation to the strained tetrahedral geometry of the QC. These results challenge the prevailing assumption that current will simply flow through the shortest through-bond path in a molecule.
将功能分子集成到单分子器件中是朝着基于尽可能小的组件实现未来计算机迈出的关键一步。在这种背景下，能够响应光在高电导率和低电导率之间转换的光开关分子是有吸引力的候选者。在此，我们展示了一种基于降冰片二烯（NB）-四环烷（QC）体系的新型稳健分子光热开关的合成及电导性质。在导通状态下通过该分子的传输由一条通过π共轭体系的路径主导，当体系切换到关断状态时，该路径不再可用。有趣的是，在关断状态下，我们发现同一路径对传输性质的贡献仅为12%。我们将这一观察结果归因于QC的应变四面体几何结构。这些结果挑战了当前流行的假设，即电流将简单地通过分子中最短的键内路径流动。
