侧链位阻效应对芴基分子电导的影响研究  

The effect of side chain steric effects on the conductance of fluorene-based molecules

作　　者：陈益斌 肖博怀 王旭[1] 王治业 孙铭俊 李云川 CHEN Yibin;XIAO Bohuai;WANG Xu;WANG Zhiye;SUN Mingjun;LI Yunchuan(State Key Laboratory of Refractory Materials and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081

出　　处：《湖北大学学报（自然科学版）》2022年第5期629-635,共7页Journal of Hubei University：Natural Science

基　　金：优秀中青年科技创新团队计划项目(T2021002)资助。

摘　　要：为了研究侧链对多苯环芴基分子电导的影响,我们采用扫描隧道显微镜裂结(STM-BJ)技术对分子骨架相同但侧链不同的一系列芴基分子的单分子电导进行测量,同时利用循环伏安法(CV)和密度泛函理论(DFT)计算对分子进行表征.研究表明,3种分子均产生高低不同的两类电导值,其中它们的低电导基本一致,而高电导之间产生明显的差别.高电导的差别可能是分子侧链产生的空间位阻阻碍了分子骨架上的电荷传导,进而使分子结电导减小.本研究有助加深对分子侧链影响单分子结电导的理解.To investigate the effect of side chains on the conductance of polyphenylene ring fluorene-based molecules, we measured the single-molecule conductance of a series of fluorene-based molecules with the same molecular backbone but different side chains using the scanning tunneling microscopy break junction(STM-BJ) technique, and also characterized the molecules using cyclic voltammetry(CV) and density functional theory(DFT) calculations. It was shown that all three molecules yielded two types of conductance values with different high and low values, where their low conductance was essentially the same, while the high conductance yielded a significant difference between them. The difference in the high conductance might be due to the steric effects generated by the molecular side chains that hindered the charge conduction on the molecular backbone, which in turn reduced the molecular junction conductance. This study contributes to the understanding of the effect of molecular side chains on the conductance of single-molecule junctions.

关 键 词：扫描隧道显微镜裂结法 循环伏安法 单分子结电导 分子构型 电子输运 

分 类 号：O626[理学—有机化学]