Functional Inorganic Materials Lab, Department of Chemistry, University of Konstanz , Universitaetsstrasse 10, 78457 Konstanz, Germany.
ACS Nano. 2016 Nov 22;10(11):10041-10048. doi: 10.1021/acsnano.6b04677. Epub 2016 Nov 7.
The solvent-mediated ability for molecularly encoded self-assembly into states of higher order (micelles, lyotropic liquid crystals) embodies the basis for many applications of surfactants in science and society. Surfactants are used frequently in recipes for nanoparticle synthesis. Because ordinary surfactants comprise insulating constituents (alkyl groups as side-chains and charged organic heads), such nanostructures are wrapped in an electrically inactive barrier, and this is a large disadvantage for future developments in nanotechnology. Implications of micelles with electrically conducting walls made from either "metallic" or "semiconducting" surfactants are huge, also in other areas such as nanoelectrocatalysis or micellar energy storage. We cross this frontier by replacing not only the hydrophilic chain but also the hydrophilic head by electronically conducting entities. We report the synthesis of surfactants with oligo para-phenylene-ethynylene as a π-conjugated side-chain attached to a redox-active, inorganic polyoxometalate cluster as charged head. It is proven that electronic communication between head and tail takes place. Hybridization on the molecular level leads to the emergence of advanced surfactant features such as semiconductor properties (E = 2.6 eV) in soft lyotropic systems (micelles, liquid crystals).
溶剂介导的分子编码自组装成更高阶状态（胶束、溶致液晶）的能力体现了表面活性剂在科学和社会中许多应用的基础。表面活性剂经常用于纳米粒子合成的配方中。由于普通表面活性剂包含绝缘成分（烷基作为侧链和带电有机头），因此这种纳米结构被包裹在非活性的电屏障中，这对纳米技术的未来发展是一个很大的劣势。由“金属”或“半导体”表面活性剂制成的具有导电壁的胶束的影响是巨大的，在纳米电催化或胶束储能等其他领域也是如此。我们通过不仅取代亲水链，而且取代亲水头来跨越这一边界，使用电子导电实体。我们报告了具有聚对亚苯基乙炔作为侧链连接到氧化还原活性的无机多金属氧酸盐簇作为带电头的表面活性剂的合成。事实证明，头和尾之间确实存在电子通信。分子水平上的杂交导致在软溶致液晶体系（胶束、液晶）中出现高级表面活性剂特性，如半导体性质（E = 2.6 eV）。
