Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
J Org Chem. 2012 Oct 19;77(20):8922-32. doi: 10.1021/jo301306y. Epub 2012 Sep 27.
The dihydroazulene (DHA)/vinylheptafulvene (VHF) photo/thermoswitch has recently attracted interest as a molecular switch for molecular electronics. In this field, Buckminsterfullerene, C(60), has been shown to be a useful anchoring group for adhering a molecular wire to an electrode. Here we have combined the two units with the overall aim to elucidate how C(60) influences the DHA-VHF switching events. Efficient synthetic protocols for making covalently linked DHA-C(60) conjugates were developed, using Prato, Sonogashira, Hay, and Cadiot-Chodkiewicz reactions. These syntheses provide as well a variety of potentially useful DHA and C(60) building blocks for acetylenic scaffolding. The two units were separated by bridges of various lengths, such as oligo(phenyleneethynylene) (OPE2 and OPE3) wires. The distance of separation was found to influence strongly the light-induced ring-opening reaction of DHA to its corresponding VHF. Thus, C(60) was found to significantly quench this conversion when situated closely to the DHA unit.
二氢薁（DHA）/乙烯庚富烯（VHF）光/热开关最近作为分子电子学的分子开关引起了人们的兴趣。在该领域中，富勒烯 C（60）已被证明是将分子线附着到电极上的有用锚固基团。在这里，我们将这两个单元结合在一起，总的目的是阐明 C（60）如何影响 DHA-VHF 开关事件。使用 Prato、Sonogashira、Hay 和 Cadiot-Chodkiewicz 反应开发了用于制备共价连接的 DHA-C（60）缀合物的有效合成方案。这些合成还提供了各种有用的 DHA 和 C（60）用于炔烃支架的构建块。这两个单元通过各种长度的桥（如寡聚（苯乙炔）（OPE2 和 OPE3）线）隔开。发现分离距离强烈影响 DHA 光诱导开环反应生成其相应的 VHF。因此，当 C（60）与 DHA 单元紧密相邻时，发现其显著猝灭了这种转化。
