Dekkiche Hervé, Gemma Andrea, Tabatabaei Fatemeh, Batsanov Andrei S, Niehaus Thomas, Gotsmann Bernd, Bryce Martin R
Department of Chemistry, Durham University, Durham, DH1 3LE, UK.
Nanoscale. 2020 Sep 28;12(36):18908-18917. doi: 10.1039/d0nr04413j. Epub 2020 Sep 9.
We report the synthesis and the single-molecule transport properties of three new oligo(phenyleneethynylene) (OPE3) derivatives possessing terminal dihydrobenzo[b]thiophene (DHBT) anchoring groups and various core substituents (phenylene, 2,5-dimethoxyphenylene and 9,10-anthracenyl). Their electronic conductance and their Seebeck coefficient have been determined using scanning tunneling microscopy-based break junction (STM-BJ) experiments between gold electrodes. The transport properties of the molecular junctions have been modelled using DFT-based computational methods which reveal a specific binding of the sulfur atom of the DHBT anchor to the electrodes. The experimentally determined Seebeck coefficient varies between -7.9 and -11.4 μV K in the series and the negative sign is consistent with charge transport through the LUMO levels of the molecules.
我们报道了三种新型低聚（亚苯基乙炔）（OPE3）衍生物的合成及其单分子输运性质，这些衍生物具有末端二氢苯并[b]噻吩（DHBT）锚定基团和各种核心取代基（亚苯基、2,5 - 二甲氧基亚苯基和9,10 - 蒽基）。通过金电极之间基于扫描隧道显微镜的断结（STM - BJ）实验测定了它们的电子电导和塞贝克系数。使用基于密度泛函理论（DFT）的计算方法对分子结的输运性质进行了建模，结果表明DHBT锚定基团的硫原子与电极之间存在特异性结合。在该系列中，实验测定的塞贝克系数在 - 7.9至 - 11.4 μV K之间变化，且负号与通过分子最低未占分子轨道（LUMO）能级的电荷传输一致。
