We report measurements on gold|single-molecule|gold junctions, using a modified scanning tunneling microscope-break junction (STM-BJ) technique, of the Seebeck coefficient and electrical conductance of a series of bridged biphenyl molecules, with meta connectivities to pyridyl anchor groups. These data are compared with a previously reported study of para-connected analogues. In agreement with a tight binding model, the electrical conductance of the meta series is relatively low and is sensitive to the nature of the bridging groups, whereas in the para case the conductance is higher and relatively insensitive to the presence of the bridging groups. This difference in sensitivity arises from the presence of destructive quantum interference in the π system of the unbridged aromatic core, which is alleviated to different degrees by the presence of bridging groups. More precisely, the Seebeck coefficient of meta-connected molecules was found to vary between −6.1 μV K⁻¹ and −14.1 μV K⁻¹, whereas that of the para-connected molecules varied from −5.5 μV K⁻¹ and −9.0 μV K⁻¹.

中文翻译：

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单分子连接中桥接联苯分子的连接性取决于热功率。

单分子| |我们对金报告测量金结，使用改进的扫描隧道显微镜断结（STM-BJ）技术，塞贝克系数和一系列桥接联苯分子的电导率，用间位连接性，以吡啶基锚组。将这些数据与先前报道的对位连接类似物的研究进行比较。在具有紧密结合模型协议，的电导元系列是比较低的，是对桥基的性质敏感，而在第在这种情况下，电导较高并且对桥接基团的存在相对不敏感。灵敏度上的这种差异是由于未桥接芳族核的π系统中存在破坏性的量子干扰而引起的，该干扰通过桥接基团的存在在不同程度上得到缓解。更精确地，塞贝克系数间-连通分子被发现μVK的变化-6.1 ^-1和-14.1μVķ ^-1，而所述的对位-连接分子从-5.5μVķ变化^-1和-9.0μV K ^-1。