Lambert Christoph, Kriegisch Volker
Universität Würzburg, Institut für Organische Chemie, Am Hubland, D-97074 Würzburg, Germany.
Langmuir. 2006 Oct 10;22(21):8807-12. doi: 10.1021/la061404t.
A versatile synthesis of triarylamine and phenothiazine end-capped oligo(phenyleneacetylene) molecular wires which are terminated by thiol functions is described. The repetitive synthesis allows the preparation of molecular wires with different chain length and different substituents attached to the wire backbone. These molecular wires were used to form dense self-assembled monolayers (SAM) on gold substrates as proved by cyclic voltammetry and quartz crystal microbalance measurements. The heterogeneous electron transfer rate constant of these SAMs was measured by impedance spectroscopy between 1 MHz and 0.1 Hz. The rate constants are somewhat larger for the triarylamine terminated systems than for the phenothiazine compound, due to the higher reorganization energy in the latter. While the molecular wires with electron withdrawing substituents display an electron transfer which is slow enough to be measurable with our impedance setup, we were unable to determine the rate of molecular wires with electron donating substituents.
本文描述了一种通用的合成方法，用于制备由硫醇官能团封端的三芳基胺和吩噻嗪封端的聚（亚苯基乙炔）分子导线。这种重复合成方法能够制备具有不同链长以及连接在分子主链上的不同取代基的分子导线。通过循环伏安法和石英晶体微天平测量证明，这些分子导线可用于在金基底上形成致密的自组装单分子层（SAM）。利用阻抗谱在1 MHz至0.1 Hz之间测量了这些SAM的异质电子转移速率常数。由于吩噻嗪化合物的重组能较高，三芳基胺封端体系的速率常数比吩噻嗪化合物的速率常数略大。虽然带有吸电子取代基的分子导线显示出的电子转移速度足够慢，可以用我们的阻抗装置进行测量，但我们无法确定带有供电子取代基的分子导线的速率。
